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Nexus 1262 /1272

High Performance Socket Meter

Electro Industries/GaugeTech

Installation & Operation ManualRevision 1.01

August 27, 2004Doc #: E151-7-01 V1.01

1800 Shames DriveWestbury, New York 11590

Tel: 516-334-0870 Fax: [email protected] www.electroind.com

“The Leader in Web Accessed Power Monitoring and Control”

Electro Industries/GaugeTech Doc # E151-7-01 V1.01

Nexus 1262/1272Installation and Operation ManualVersion 1.01

Published by:Electro Industries/GaugeTech1800 Shames DriveWestbury, NY 11590

All rights reserved. No part of thispublication may be reproduced ortransmitted in any form or by anymeans, electronic or mechanical,including photocopying, recording,or information storage or retrievalsystems or any future forms of duplication, for any purpose otherthan the purchaser’s use, without the expressed written permission ofElectro Industries/GaugeTech.

© 2004Electro Industries/GaugeTech

Printed in the United States ofAmerica.

Electro Industries/GaugeTech Doc # E151-7-01 V1.01 i

Electro Industries/GaugeTech Doc # E151-7-01 V1.01 ii

Customer Service and SupportCustomer support is available 9:00 am to 4:30 pm, eastern standard time, Monday through Friday.Please have the model, serial number and a detailed problem description available. If the problem concerns a particular reading, please have all meter readings available. When returning any merchandiseto EIG, a return materials authorization number is required. For customer or technical assistance, repairor calibration, phone 516-334-0870 or fax 516-338-4741.

Product WarrantyElectro Industries/GaugeTech warrants all products to be free from defects in material and workmanshipfor a period of four years from the date of shipment. During the warranty period, we will, at our option,either repair or replace any product that proves to be defective.

To exercise this warranty, fax or call our customer-support department. You will receive prompt assistance and return instructions. Send the instrument, transportation prepaid, to EIG at 1800 ShamesDrive, Westbury, NY 11590. Repairs will be made and the instrument will be returned.

Limitation of WarrantyThis warranty does not apply to defects resulting from unauthorized modification, misuse, or use for anyreason other than electrical power monitoring. The Nexus Monitor is not a user-serviceable product.

OUR PRODUCTS ARE NOT TO BE USED FOR PRIMARY OVER-CURRENT PROTECTION. ANYPROTECTION FEATURE IN OUR PRODUCTS IS TO BE USED FOR ALARM OR SECONDARYPROTECTION ONLY.

THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED,INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR APARTICULAR PURPOSE. ELECTRO INDUSTRIES/GAUGETECH SHALL NOT BE LIABLE FORANY INDIRECT, SPECIAL OR CONSEQUENTIAL DAMAGES ARISING FROM ANY AUTHO-RIZED OR UNAUTHORIZED USE OF ANY ELECTRO INDUSTRIES/GAUGETECH PRODUCT.LIABILITY SHALL BE LIMITED TO THE ORIGINAL COST OF THE PRODUCT SOLD.

Statement of CalibrationOur instruments are inspected and tested in accordance with specifications published by ElectroIndustries/GaugeTech. The accuracy and a calibration of our instruments are traceable to the NationalInstitute of Standards and Technology through equipment that is calibrated at planned intervals by comparison to certified standards.

DisclaimerThe information presented in this publication has been carefully checked for reliability; however, noresponsibility is assumed for inaccuracies. The information contained in this document is subject tochange without notice.

This symbol indicates that the operator must refer to an explanation in the operatinginstructions. Please see Chapter 3, Hardware Installation, for important safetyinformation regarding installation and hookup of the Nexus 1262 & 1272 Meters.

Electro Industries/GaugeTech Doc # E151-7-01 V1.01 iii

About Electro Industries/GaugeTech

Founded in 1973 by engineer and inventor Dr. Samuel Kagan, Electro Industries/GaugeTech changed theface of power monitoring forever with its first breakthrough innovation: an affordable, easy-to-use ACpower meter.

Thirty years later, Electro Industries/GaugeTech, the leader in Web-Accessed Power Monitoring, continues to revolutionize the industry with the highest quality, cutting edge power monitoring and control technology on the market today. An ISO 9001:2000 certified company, EIG sets the industrystandard for advanced power quality and reporting, revenue metering and substation data acquisition andcontrol. The Nexus 1262/1272 transformer-rated, polyphase meter utilizing Accu-Measure© DigitalSensing Technology is an example of this standard. EIG products can be found on site at virtually all oftoday’s leading manufacturers, industrial giants and utilities.

All EIG products are designed, manufactured, tested and calibrated at our facility in Westbury, NewYork.

Applications:

Web-Accessed Multifunction Power Monitoring and Control

Single and Multifunction Power Monitoring

Power Quality Monitoring

Onboard Data Logging for Trending Power Usage and Quality

Disturbance Analysis

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Table of Contents

Quick Start Guide for Nexus Type S Meters Q-1

Chapter 1: Quick Start Up for Nexus S Type Meters1.1: Start-Up and Bench Check . . . . . . . . . . . . . . . . . . . . . . . . . 1-11.1.1: Meters with Auxiliary Power . . . . . . . . . . . . . . . . . . . . . . . 1-11.1.2: Meters without Auxiliary Power . . . . . . . . . . . . . . . . . . . . . . 1-11.2: PC to Nexus Serial Communications . . . . . . . . . . . . . . . . . . . . . 1-21.2.1: Optical Port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-21.2.2: Serial Communications . . . . . . . . . . . . . . . . . . . . . . . . . . 1-21.3: Install Communicator EXT Software & Connect . . . . . . . . . . . . . . . 1-21.4: Configure Programmable Settings . . . . . . . . . . . . . . . . . . . . . . 1-31.5: Device Profile Screens . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-31.5.1: Save the New Program . . . . . . . . . . . . . . . . . . . . . . . . . . 1-61.6: Field Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

Chapter 2: Nexus 1262/1272 Overview2.1: The Nexus 1262/1272 Multiparameter Power Meter . . . . . . . . . . . . . . 2-12.2: Accu-Measure© Technology - Theory of Operation . . . . . . . . . . . . . . 2-12.3: Advanced Measurement Functionality . . . . . . . . . . . . . . . . . . . . 2-42.3.1: Advanced Revenue Billing Capability . . . . . . . . . . . . . . . . . . . 2-42.3.2: Advanced Communications and I/O Capabilities . . . . . . . . . . . . . . . 2-52.3.3: Flicker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-62.3.4: Display Screens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-62.3.5: Additional Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-62.3.6: Nexus External I/O Modules . . . . . . . . . . . . . . . . . . . . . . . 2-62.3.6.1: Optional P40N LED Remote Display . . . . . . . . . . . . . . . . . . . 2-62.3.6.2: Optional P60N Touch Screen Remote Display . . . . . . . . . . . . . . . 2-62.4: Nexus 1262/1272 Forms . . . . . . . . . . . . . . . . . . . . . . . . . . 2-72.5: Nexus 1262/1272 Specifications Overview . . . . . . . . . . . . . . . . . . 2-82.6: Nexus 1262/1272 Logging Specifications . . . . . . . . . . . . . . . . . . 2-102.7: DNP V3.00 Level 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10

Chapter 3: Operating Instructions for Nexus 1262 & 12723.1: Nameplate Information . . . . . . . . . . . . . . . . . . . . . . . . . . 3-13.2: Basic Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-33.3: Display Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-43.4: Nexus 1262/1272 Programmable Display Navigation Map . . . . . . . . . . . 3-53.5: Programmable Display Overview . . . . . . . . . . . . . . . . . . . . . . 3-63.6: Programmable Display Setup . . . . . . . . . . . . . . . . . . . . . . . . 3-73.7: Programmable Display Screens . . . . . . . . . . . . . . . . . . . . . . 3-103.7.1: Programmable Display Screens Modifiers . . . . . . . . . . . . . . . . . 3-12

Chapter 4: Testing for Nexus 1262/12724.1: Testing Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14.1.1: Test Pulse LED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14.1.2: LCD Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2

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4.2: Test Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-24.2.1: Entering Test Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-24.2.2: Using Test Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-34.2.3: Test Mode Exit Delay Setting . . . . . . . . . . . . . . . . . . . . . . . 4-44.2.4: Test Mode Preset Accumulators . . . . . . . . . . . . . . . . . . . . . . 4-54.2.5: Exiting Test Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6

Chapter 5: Serial Communication Wiring5.1: Communication Overview . . . . . . . . . . . . . . . . . . . . . . . . . 5-15.2: Communicating to the Nexus through the ANSI C12.1 Optical Port . . . . . . . 5-25.3: RS-485 Serial Communication . . . . . . . . . . . . . . . . . . . . . . . 5-35.3.1: RS-485 Wiring Fundamentals (Ports 1 & 4) . . . . . . . . . . . . . . . . . 5-35.3.2: RS-485 Connection- Monitor to a Computer or PLC . . . . . . . . . . . . . 5-75.3.3: RJ-11 (Telephone Line) Connection- Meter with INP2 Option to PC . . . . . . 5-75.3.4: RJ-45 Connection- Meter with 10/100BaseT (INP10/100) Option . . . . . . . 5-75.3.5: Modem/Ethernet Connection- Meter with INP102 (Combo Card) Option . . . . 5-75.3.6: RS-485 Connection- Meter to an RS-485 Master . . . . . . . . . . . . . . 5-85.3.7: RS-485 Connection- Monitor to the P40N LED External Display . . . . . . . 5-95.3.8: RS-485 Connection- Monitor to the P60N Touch Screen External Display . . . 5-105.3.9: Communication Ports on the I/O Modules . . . . . . . . . . . . . . . . . 5-115.3.10: RS-485 Connection—Monitor to I/O Modules . . . . . . . . . . . . . . . 5-125.3.11: Steps to Determine Power Needed . . . . . . . . . . . . . . . . . . . . 5-135.3.12: I/O Modules’ Factory Settings and VA Ratings . . . . . . . . . . . . . . 5-135.3.13: Linking Multiple Devices in Series . . . . . . . . . . . . . . . . . . . 5-145.3.14: Remote Communication Over Telephone Lines Using the RS-485 Port . . . . 5-155.3.15: Programming Modems for Remote Communication . . . . . . . . . . . . 5-175.3.16: Selected Modem Strings . . . . . . . . . . . . . . . . . . . . . . . . 5-185.3.17: High Speed Inputs Connection (1272 Only) . . . . . . . . . . . . . . . . 5-185.3.18: IRIG-B Connections (1272 Only) . . . . . . . . . . . . . . . . . . . . 5-195.3.19: Time Synchronization Alternatives . . . . . . . . . . . . . . . . . . . . 5-205.4: INP2 Internal Modem with Dial In/Dial Out Option5.4.1: Hardware Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 5-215.4.2: Hardware Connection . . . . . . . . . . . . . . . . . . . . . . . . . . 5-215.4.3: Dial-In Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-215.4.4: Dial-Out Function . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-225.5: Total Web Solutions5.5.1: Hardware Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 5-235.5.2: Hardware Connection . . . . . . . . . . . . . . . . . . . . . . . . . . 5-235.6: INP102 Ethernet/Modem Combination5.6.1: Hardware Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 5-255.6.2: Hardware Connection . . . . . . . . . . . . . . . . . . . . . . . . . . 5-25

Chapter 6: Hardware Installation6.1: Mounting the Nexus Socket Meter . . . . . . . . . . . . . . . . . . . . . . 6-16.1.1: Cable Color Key . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-46.2: Internal Battery Installation and Maintenance . . . . . . . . . . . . . . . . . 6-56.2.1: Battery Holder Detail . . . . . . . . . . . . . . . . . . . . . . . . . . 6-66.2.2: Battery Safety and Disposal . . . . . . . . . . . . . . . . . . . . . . . . 6-6

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6.3: Mounting the Optional Nexus P40N LED External Display . . . . . . . . . . . 6-76.4: Mounting the Optional Nexus P60N Touch Screen External Display . . . . . . . 6-86.5: Daisy Chain Meters with the P60N . . . . . . . . . . . . . . . . . . . . . 6-96.6: Mounting the Nexus External I/O Modules . . . . . . . . . . . . . . . . . 6-10

Chapter 7: Nexus Time-of-Use7.1: Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-17.2: The Nexus TOU Calendar . . . . . . . . . . . . . . . . . . . . . . . . . 7-17.3: TOU Frozen & Active Registers . . . . . . . . . . . . . . . . . . . . . . 7-27.4: Updating, Retrieving and Replacing TOU Calendars . . . . . . . . . . . . . . 7-27.5: Daylight Savings and Demand . . . . . . . . . . . . . . . . . . . . . . . 7-2

Chapter 8: Transformer Loss Compensation8.1: Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-18.2: Nexus 1262/1272 Transformer Loss Compensation . . . . . . . . . . . . . . 8-38.2.1: Loss Compensation in Three Element Installations . . . . . . . . . . . . . . 8-48.2.1.1: Three Element Loss Compensation Worksheet . . . . . . . . . . . . . . . 8-5

Chapter 9: Using the Nexus External Displays (1262 & 1272)9.1: Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-19.2: Nexus P40N LED External Display . . . . . . . . . . . . . . . . . . . . . 9-29.3: Dynamic Readings Mode . . . . . . . . . . . . . . . . . . . . . . . . . 9-29.4: Navigational Map of Dynamic Readings Mode . . . . . . . . . . . . . . . . 9-49.5: Nexus Information Mode . . . . . . . . . . . . . . . . . . . . . . . . . 9-59.6: Navigational Map of Nexus Information Mode . . . . . . . . . . . . . . . . 9-69.7: Display Features Mode . . . . . . . . . . . . . . . . . . . . . . . . . . 9-79.8: Navigational Map of Display Features Mode . . . . . . . . . . . . . . . . . 9-89.9: Nexus P60N Touch Screen External Display and Screens . . . . . . . . . . . 9-99.10: Navigational Map for P60N Touch Screen External Display . . . . . . . . . 9-149.11: Optional P40N LED External Remote Display Specifications . . . . . . . . . 9-159.12: Optional P60N Touch Screen Remote Display Specifications . . . . . . . . . 9-15

Chapter 10: Nexus External I/O Modules (1262 & 1272)10.1: Hardware Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 10-110.1.1: Port Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-210.2: Installing Nexus External I/O Modules . . . . . . . . . . . . . . . . . . 10-310.2.1: Power Source for I/O Modules . . . . . . . . . . . . . . . . . . . . . 10-410.3: Using Multiple I/O Modules . . . . . . . . . . . . . . . . . . . . . . . 10-510.3.1: Steps for Attaching Multiple I/O Modules . . . . . . . . . . . . . . . . 10-510.4: Factory Settings and Reset Button . . . . . . . . . . . . . . . . . . . . 10-610.5: Analog Transducer Signal Output Modules . . . . . . . . . . . . . . . . . 10-710.5.1: Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-710.5.2: Normal Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-810.6: Analog Input Modules . . . . . . . . . . . . . . . . . . . . . . . . . . 10-910.6.1: Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-910.6.2: Normal Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-10

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10.7: Digital Dry Contact Relay Output (Form C) Module . . . . . . . . . . . . 10-1110.7.1: Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1110.7.2: Communication . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1210.7.3: Normal Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1210.8: Digital Solid State Pulse Output (KYZ) Module . . . . . . . . . . . . . . 10-1310.8.1: Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1310.8.2: Communication . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1410.8.3: Normal Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1410.9: Digital Status Input Module . . . . . . . . . . . . . . . . . . . . . . . 10-1510.9.1: Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1510.9.2: Communication . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1510.9.3: Normal Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1610.10: Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-16

Chapter 11: Electrical Installation for Nexus 1262/1272 (Type S)11.1: Wiring Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-111.2: 9S Meter Mounted in S/A Adapter . . . . . . . . . . . . . . . . . . . . 11-12

Chapter 12: Nexus 1262/1272 Switchboard Meter (Type Z)12.1: Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-112.2: Labels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-212.3: Specifications and Dimensions . . . . . . . . . . . . . . . . . . . . . . 12-312.4: Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-512.5: Wiring Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-6

Chapter 13: Nexus Calculations13.1: Measurements and Calculations . . . . . . . . . . . . . . . . . . . . . 13-113.2: Demand Integrators . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-6

Chapter 14: EN 50160 Flicker14.1: Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-114.2: Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . 14-114.3: Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-314.4: Software - User Interface . . . . . . . . . . . . . . . . . . . . . . . . 14-414.5: Logging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-714.6: Polling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-714.7: Log Viewer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-714.8: Performance Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-8

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Appendix A: Transformer Loss Compensation Excel Spreadsheet with ExamplesA.1: Calculating Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1A.2: Excel Spreadsheet with Example Numbers . . . . . . . . . . . . . . . . . A-1

Appendix B: Blade Configuration for Forms 9S & 36S, 39S and 45SB.1: 1262 and 1272 Forms . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1B.2: Blade Configuration Drawings . . . . . . . . . . . . . . . . . . . . . . . B-1

Appendix C: TFTP Server Program SetupC.1: TFTP Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-1

Appendix D: Three-Phase Power MeasurementD.1: Three-Phase System Configurations . . . . . . . . . . . . . . . . . . . . D-1D.1.1: Wye Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-1D.1.2: Delta Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-3D.1.3: Blondell’s Theorem and Three-Phase Measurement . . . . . . . . . . . . . D-4D.2: Power Energy and Demand . . . . . . . . . . . . . . . . . . . . . . . . D-6D.3: Reactive Energy and Power Factor . . . . . . . . . . . . . . . . . . . . . D-8D.4: Harmonic Distortion . . . . . . . . . . . . . . . . . . . . . . . . . . . D-10D.5: Power Quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-13

Glossary of Terms

List of Figures

Chapter 1: Quick Start Up for Nexus Type S MetersFigure 1.1: The Nexus 1272 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1Figure 1.2: The Nexus 1272 Rear View Diagram . . . . . . . . . . . . . . . . . . . 1-1Figure 1.3: Form 9S & 36S Aux Terminals . . . . . . . . . . . . . . . . . . . . . . 1-1Figure 1.4: Form 45S Aux Terminals . . . . . . . . . . . . . . . . . . . . . . . . 1-1Figure 1.5: SC-1A Smart Coupler . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Chapter 2: Nexus 1262/1272 OverviewFigure 2.1: The Nexus 1272 Meter . . . . . . . . . . . . . . . . . . . . . . . . . 2-1Figure 2.2: How the Nexus 1272 Processes Inputs . . . . . . . . . . . . . . . . . . . 2-2Figure 2.3: How the Nexus 1262 Processes Inputs . . . . . . . . . . . . . . . . . . . 2-3

Chapter 3: Operating InstructionsFigure 3.1: Nexus 1272 Nameplate . . . . . . . . . . . . . . . . . . . . . . . . . 3-1Figure 3.2: Nexus 1262/1272 Switches and Indicators . . . . . . . . . . . . . . . . . 3-3

Chapter 4: Testing for Nexus 1262/1272Figure 4.1: The Nexus 1272 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

Chapter 5: Serial Communication WiringFigure 5.1: Communication Overview . . . . . . . . . . . . . . . . . . . . . . . . 5-1Figure 5.2: Nexus 1272 Optical Port . . . . . . . . . . . . . . . . . . . . . . . . . 5-2

Figure 5.3: SC-1A Smart Coupler . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3Figure 5.4: 1262/1272 2-Wire RS-485 Port Detail . . . . . . . . . . . . . . . . . . . 5-4Figure 5.5: 2-Wire RS-485 Connection . . . . . . . . . . . . . . . . . . . . . . . . 5-5Figure 5.6: Incorrect “T” and “Star” Topologies . . . . . . . . . . . . . . . . . . . . 5-6Figure 5.7: Monitor Connected to an RS-485 Master . . . . . . . . . . . . . . . . . . 5-8Figure 5.8: Nexus Monitor Connected to LED P40N External Display . . . . . . . . . . 5-9Figure 5.9: P60N Touch Screen Display Port . . . . . . . . . . . . . . . . . . . . 5-10Figure 5.10: Communication Ports on the Nexus I/O Modules . . . . . . . . . . . . . 5-11Figure 5.11: Nexus Monitor Connected to Nexus I/O Module . . . . . . . . . . . . . 5-12Figure 5.12: Linking Multiple Devices in Series . . . . . . . . . . . . . . . . . . . 5-14Figure 5.13: Linking Isolated Units in Series . . . . . . . . . . . . . . . . . . . . . 5-14Figure 5.14: Remote Connections-RS-485 . . . . . . . . . . . . . . . . . . . . . . 5-15Figure 5.15: High Speed Inputs Connection . . . . . . . . . . . . . . . . . . . . . 5-18Figure 5.16: IRIG-B Connection . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19

Chapter 6: Hardware InstallationFigure 6.1: Nexus 1262 or 1272 Mounting Dimensions . . . . . . . . . . . . . . . . . 6-1Figure 6.2: Nexus 1272 Rear View Diagram . . . . . . . . . . . . . . . . . . . . . 6-2Figure 6.3: Nexus 1262/1272 Mounted in A-Base Bottom . . . . . . . . . . . . . . . 6-3Figure 6.4: Nexus 1262/1272 Mounted (Side View) . . . . . . . . . . . . . . . . . . 6-3Figure 6.5: Nexus 1272 without Internal Shroud . . . . . . . . . . . . . . . . . . . . 6-5Figure 6.6: Battery Holder Detail . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6Figure 6.7: Nexus P40N LED External Display Mounting Diagrams . . . . . . . . . . . 6-7Figure 6.8: Nexus P60N Touch Screen Display Mounting Diagram . . . . . . . . . . . 6-8Figure 6.9: Nexus P60N Back Detail . . . . . . . . . . . . . . . . . . . . . . . . 6-8Figure 6.10: Cutout for Nexus P60N Touch Screen Display . . . . . . . . . . . . . . . 6-9Figure 6.11: Daisy Chain Meters with the P60N Touch Screen Display . . . . . . . . . . 6-9Figure 6.12: Nexus I/O Modules Mounting Diagram, Overhead View . . . . . . . . . . 6-10Figure 6.13: Nexus I/O Module Communication Ports . . . . . . . . . . . . . . . . 6-10Figure 6.14: Nexus I/O Modules Mounting Diagram, Front View . . . . . . . . . . . . 6-11Figure 6.15: Nexus I/O Modules with PSIO Mounting Diagram . . . . . . . . . . . . 6-11Figure 6.16: I/O Wiring Detail . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-12

Chapter 8: TransformerLoss CompensationFigure 8.1: Low Voltage Metering Installation Requiring Loss Compensation . . . . . . . 8-1Figure 8.2: Joint Ownership Line Metering Requiring Loss Compensation . . . . . . . . 8-1

Chapter 9: Using the Nexus External DisplaysFigure 9.1: Nexus P40N LED External Display . . . . . . . . . . . . . . . . . . . . 9 -1Figure 9.2: Nexus P60N Touch Screen External Display . . . . . . . . . . . . . . . . 9 -9

Screen Captures for All Readings . . . . . . . . . . . . . . . . 9 - 9 - 9 -13

Chapter 10: Nexus External I/O ModulesFigure 10.1: I/O Module Components . . . . . . . . . . . . . . . . . . . . . . . . 10-1Figure 10.2: Nexus Monitor Connected to I/O Module . . . . . . . . . . . . . . . . 10-3Figure 10.3: PSIO Power Source (Side View) . . . . . . . . . . . . . . . . . . . . 10-4Figure 10.4: Power flow from PSIO to I/O Module . . . . . . . . . . . . . . . . . . 10-4Figure 10.5: Labels for the PSIO Power Source . . . . . . . . . . . . . . . . . . . 10-4Figure 10.6: Multiple I/Os . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-5

Electro Industries/GaugeTech Doc # E151-7-01 V1.01 x

Chapter 11: Electrical InstallationFigure 11.1: Form 9S 4-Wire Wye, no PTs, 3 CTs . . . . . . . . . . . . . . . . . . 11-2Figure 11.2: Form 9S 4-Wire Delta, no PTs, 3 CTs . . . . . . . . . . . . . . . . . . 11-3Figure 11.3: Form 9S 4-Wire Wye, 3 PTs and 3 CTs . . . . . . . . . . . . . . . . . 11-4Figure 11.4: Form 36S 4-Wire Wye, 2 PTs, 3 CTs . . . . . . . . . . . . . . . . . . 11-5Figure 11.5: Form 39S 4-Wire Wye, no PTs, 4 CTs . . . . . . . . . . . . . . . . . . 11-6Figure 11.6: Form 39S 4-Wire Wye, 3 PTs, 4 CTs . . . . . . . . . . . . . . . . . . 11-7Figure 11.7: Form 45S 4-Wire Wye, 2 PTs, 3 CTs . . . . . . . . . . . . . . . . . . 11-8Figure 11.8: Form 45S 4-Wire Wye, no PTs, 3 CTs . . . . . . . . . . . . . . . . . . 11-9Figure 11.9: Form 45S 3-Wire Delta, no PTs, 2 CTs . . . . . . . . . . . . . . . . . 11-10Figure 11.10: Form 45S 3-Wire Delta, 2 PTs, 2 CTs . . . . . . . . . . . . . . . . . 11-11Figure 11.11: Form 9S mounted in an S/A Adapter . . . . . . . . . . . . . . . . . 11-12

Chapter 12: Nexus 1262/1272 Switchboard MeterFigure 12.1: 1262/1272 Switchboard Meter, Front View . . . . . . . . . . . . . . . 12-1Figure 12.2: Front View of the 1262/1272 Switchboard Meter . . . . . . . . . . . . . 12-2Figure 12.3: Options Label for the 1262/1272 Switchboard Meter . . . . . . . . . . . 12-2Figure 12.4: Switchboard Meter, Back View . . . . . . . . . . . . . . . . . . . . . 12-3Figure 12.5: Switchboard Meter, Side View . . . . . . . . . . . . . . . . . . . . . 12-4Figure 12.6: Front Case showing Built-In Screws . . . . . . . . . . . . . . . . . . 12-5Figure 12.7: Back Angle View of Switchboard Meter . . . . . . . . . . . . . . . . . 12-6Figure 12.8: Form 9Z 4-Wire Wye, no PTs, 3 CTs . . . . . . . . . . . . . . . . . . 12-7Figure 12.9: Form 9Z 4-Wire Delta, no PTs, 3 CTs . . . . . . . . . . . . . . . . . . 12-8Figure 12.10: Form 9Z 4-Wire Wye, 3 PTs, 3 CTs . . . . . . . . . . . . . . . . . . 12-9Figure 12.11: Form 45Z 3-Wire Delta, no PTs, 2 CTs . . . . . . . . . . . . . . . . 12-10Figure 12.12: Form 45Z 3-Wire Delta, 2 PTs, 2 CTs . . . . . . . . . . . . . . . . . 12-11

Chapter 14: FlickerFigure 14.1: Simulation of Eye Brain Response . . . . . . . . . . . . . . . . . . . 14-3

Appendix B: Blade ConfigurationFigure B.1: Form 9S & 36S Base with Knock Out Holes . . . . . . . . . . . . . . . B-2Figure B.2: Form 39S Base with Knock Out Holes . . . . . . . . . . . . . . . . . . B-2Figure B.3: Form 45S Base with Knock Out Holes . . . . . . . . . . . . . . . . . . B-3

Appendix C: TFTP Server Program SetupFigure C.1: TFTPD32 Program Screen . . . . . . . . . . . . . . . . . . . . . . . C-1Figure C.2: TFTPD32 Settings Screen . . . . . . . . . . . . . . . . . . . . . . . . C-2

Electro Industries/GaugeTech Doc # E151-7-01 V1.01 xi

Electro Industries/GaugeTech Doc # E151-7-01 V1.01 xii

Appendix D: Three-Phase Power MeasurementFigure D.1: Three-Phase Wye Winding . . . . . . . . . . . . . . . . . . . . . . . D-1Figure D.2: Phasor diagram showing Three-phase Voltages and Currents . . . . . . . . . D-2Figure D.3: Three-Phase Delta Winding Relationship . . . . . . . . . . . . . . . . . D-3Figure D.4: Phasor diagram showing Three-phase Voltages, Currents, Delta Connected . . D-3Figure D.5: Phasor diagram showing Three-phase, 4-wire Delta Connected System . . . . D-4Figure D.6: Three-Phase Wye Load . . . . . . . . . . . . . . . . . . . . . . . . . D-5Figure D.7: Power Use Over Time . . . . . . . . . . . . . . . . . . . . . . . . . D-6Figure D.8: Energy Use and Demand . . . . . . . . . . . . . . . . . . . . . . . . D-8Figure D.9: Voltage and Complex Current . . . . . . . . . . . . . . . . . . . . . . D-9Figure D.10: Nondistorted Current Waveform . . . . . . . . . . . . . . . . . . . . D-10Figure D.11: Distorted current wave . . . . . . . . . . . . . . . . . . . . . . . . D-11Figure D.12: Waveforms of the Harmonics . . . . . . . . . . . . . . . . . . . . . D-11

Tables

Table 6.1: Cable Color Key . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4Table 11.1: Nexus 1262/1272 Forms Type S) . . . . . . . . . . . . . . . . . . . . 11-1Table 12.1: 1262/1272 Switchboard Meter Forms (Type Z) . . . . . . . . . . . . . . 12-6Table D.1: Common Phase Voltages on Wye Services . . . . . . . . . . . . . . . . . D-2Table D.2: Power and Energy Relationship Over Time . . . . . . . . . . . . . . . . D-7Table D.3: Typical Power Quality Problems and Sources . . . . . . . . . . . . . . . D-13

Electro Industries/Gauge Tech Doc # E 151-7-01 V1.01 Q-1

Quick Start Guide for Nexus Type S Meters

Q.1: Bench Check Bench Check saves field time.

Q.1.1: Meters with Auxiliary Power Apply appropriate power to Auxiliary power cable. Display information scrolls. See Fig. 1.2.

Q.1.2: Meters without Auxiliary Power Apply appropriate power to voltage terminals. Terminals are determined by Meter Form (on the front plate of the meter). For Forms 9S, 36S & 39S, connect power source to one of the three left most and to the right most voltage terminals (center row of smaller terminals). See Fig. 1.3 & 1.4.

Q.2: PC to Nexus CommunicationsQ.2.1: Optical Port

Connect with Modbus RTU, 9600.Connect SC-1A Smart Coupler (RS-232) from Nexus’Optical Port to a computer serial port (or)

Q.2.2: Serial CommunicationsConnect with Modbus RTU, 57600.Connect Nexus Port 1 (or 4) (RS-485) to PC's RS-232 serial port via a Unicom RS-485/ RS-232 Converter.

Q.3: Install Communicator EXT Software & ConnectEthernet: Connect with Network, Modbus TCP, 57600.Modem: Connection Manager, Modbus ASCII, 57600.

Q.4: Configure Programmable SettingsFrom Main Screen, click Profile Icon. Communicator EXTdisplays the Meter's Initial Profile for editing.

Before making changes, click SAVE to Save the Initial Settingsas Initial Settings.NPS* on hard drive.

Click on the (+/-) icon, double-click on the selected parameter. The screen appears. Make changes. Click OK. Then use buttons at the bottom of the screen to UPDATE DEVICE, SAVE, LOAD, print a REPORT or CANCEL. Section 1.5 reviews screens.

SAVE the new NPS File as Modified Settings.NPS or as a uniqueidentifying name (Example: Unique System ID or Customer’s Name).

To implement changes, click UPDATE DEVICE.To LOAD a new or different file, select a file name.RESET ALL LOGS in Communicator EXT Main screen > Tools > Reset.

Q.5: Device Profile ScreensGeneral SettingsSite Information (CT, PT Ratios)If you are using Block Demand, Transformer Loss Compensation, other than 15 minute demand, or Load Profile Recording (Trending in Communicator EXT)the Initial Settings should be changed. NOTE: Any change to CT settings will automatically update the corresponding Full Scale value in the Limit and Waveform Full Scales settings and will effect all other settings. NOTE: Make sure settings are correct for installation site.

OptionalAuxPowerCable

Fig. Q.1: The Nexus 1272 Fig. Q.2: 1272 Rear Diagram

Fig. Q.3: 9S, 36S Aux Terminals Fig. Q.4: 45S Aux Terminals

Fig. Q.5: 1262/1272 Device Profile

Fig. Q.6: CT & PT Settings

VoltageTerminals

Common

Modem/Ethernet

Hanger

Electro Industries/Gauge Tech Doc # E 151-7-01 V1.01 Q-2

Limit & Waveform Full ScalesThese settings are based on a percentage of Full Scales, which are derived from the CT Ratios andcan be changed without effecting accuracy. Be sure to set the CT Ratios first.

Time Settings (not shown)(Initial Setting is - 5:00 Eastern Time)- 6:00 = Central Time - 9:00 Pacific Time- 7:00 = Mountain Time -10:00 Hawaii- 8:00 = Pacific Time -11:00 Midway IslandAuto DST (Daylight Savings Time) is Enabled.

Communications SettingsPorts 1 & 4 are programmable. Port 4 is INITIALLYSET for External Devices and can be changed. For Internal Modem & Network Options, set Advanced Settings & Dial Out Profile.

Revenue & Energy SettingsBlock Average DemandInput settings for Demand Integration. Click OK.

Display Configuration - Screen AssignmentsUse pull down windows to set up Display Modes & Screens.

Power Quality & Alarm SettingsLimitsDouble-click on a column or setting, change setting. Click OK.

Waveform - CBEMA Profile (PQ Thresholds)Triggers for waveforms are set here based on a percentage of Full Scales (set on the Limit & Waveform Full Scales screen).Set Sampling Rate and Total Captures. Click OK.

Trending Profile SettingsLog Time Intervals (not shown)Set Intervals for Time Stamps from 1 second to 18 Hours. Based on Nexus time. Click OK. Time is set in the Tools Menu.

Trending Setup for Historical Logs (not shown)Using pull down menus, select Type of Snapshot and Channel. Click Add or Remove. A running Total of Bytes Used appears on the screen. Click OK.

NOTE: This card is intended to be a brief tutorial for the Installation and Configuration of the Nexus 1262/1272 Power Meter. This card does not purport to cover all details or variations in equipment. All work should be done by appropriate qualified personnel. For details, refer to later chapters & Communicator EXT Software Manual.

*Alternate access to the Device Profile NPS File (Nexus Programmable Settings File) on www.electroind.com.

Electro Industries/Gauge Tech Doc # E 151-7-01 V1.01 1-1

Chapter 1Quick Start Up for Nexus Type S Meters

The Nexus 1262/1272 Multiparameter Socket Meter can be installed in three ways; Type S Meter, Type A Meter (on an A Base) and Type Z Meter (in a Switchboard case). This Quick Start Guide is meant to give the field technician the basic steps for installation of the Type S Meter. Steps are detailed in later chapters of this manual.

1.1: Start-UUp and Bench CheckPower Up and Bench Check saves field time.

1.1.1: Meters with Auxiliary Power If the meter has an Auxiliary Power cable(Fig. 1.2), apply appropriate power to the 2 leads of the power cable. Meter information scrolls on the display.

1.1.2: Meters without Auxiliary Power To energize meters without Auxiliary Power,apply appropriate power to the voltage terminals of the meter. Terminals vary by Meter Form. The Nexus 1272 Meter Form (FM 9S, 36S, 39S or 45S) is shown in the white block under the display (Fig. 1.1). See Figures 1.3 & 1.4 to determine terminals.

For Form 9S, 36S and 39S meters, connect appropriate power to the one of the threeleft most and to the right most voltage terminals (center row of smaller terminals).They are small, bold terminals in Figures 1.3 & 1.4. (The larger terminals are current terminals.) NOTE: Form 39S uses the same voltage terminals but the current terminals differ.

When the meter is energized, the display lights up and meter information scrolls on the display. This completes a 95% test of meter functionality.

OptionalAuxPowerCable

Cable 1Port 1Port 4IRIG-B

Cable 3Optional KYZ Cable

Cable 2Cable to High SpeedInputs

RJ-45 Ethernet

ModemCable 4RS-485 GatewayCable 5RJ-11 ModemCable 7Battery

EthernetCable 6RJ-45 Ethernet

OPTIONAL COMMUNICATIONCombo Modem / Ethernet

Cable 4RS-485 GatewayCable 5RJ-11 ModemCable 6

Figure 1.1: The Nexus 1272

Figure 1.2: The Nexus 1272 Rear View Diagram

Fig 1.3: Form 9S & 36S Aux Terminals Fig 1.4: Form 45S Aux Terminals

VoltageTerminals

Common


1.2: PC to Nexus Serial Communications

1.2.1: Optical PortConnect with Modbus RTU, 9600 Baud Rate.Verify that there is a fresh battery in the SC-1A Smart Coupler or thatit is powered by the external power supply. Connect the SC-1ASmart Coupler (RS-232) at one end to the Nexus’ Optical Port. Atthe other end, connect to a computer serial port (or)

1.2.2: Serial CommunicationsConnect with Modbus RTU, 57600 Baud Rate.Connect Nexus Port 1 (or 4) (RS-485) serial communications port to PC's RS-232 serial port via a Unicom RS-485/RS-232 Converter.

Programming the Nexus MeterProgramming the Nexus meter is much simpler than other high function meters. Here are somethings you may find different about the Nexus:

• All functions are operating simultaneously in the Nexus meter. There is no need to select which subset of functionality is needed for this application.

• The Nexus meter is shipped with Initial Settings that will get you started. Programming consists primarily of modifying the Initial Settings program. You can be creative or not.

• The key steps to programming a Nexus meter are:1. Setting up communications.2. Entering site information (CT and PT ratios).3. Setting limits.4. Selecting items to be displayed.

1.3: Install Communicator EXT Software & ConnectSee section 1.2 of Communicator EXT Manual for details. The setup process is simple, just insert a Communicator EXT CD into the disc drive; the software walks you through the installation process.

If auto-start doesn't happen, use Windows Explorer:1. Right-click Start Button and select Explorer. 2. Then select the drive with the Communicator EXT CD. 3. To start installation, double click "Nexus Setup.exe".

Use Communicator EXT's Quick Connect (or Connect) function to set up the Communication link.The Command is: Connection > Quick Connect (or Connect).

Ethernet Connection: Connect with Network, Modbus TCP, 57600.Modem: Connection Manager, Modbus ASCII, 57600.

The Device Status Screen appears when the connection is complete.

Fig 1.5: SC-1A Smart Coupler


1.4: Configure Programmable Settings

• From the Communicator EXT Main screen, click the Profile Icon, the left most icon on the Tool Bar. Communicator EXT will then copy the Meter's Initial Profile into computer memory and display it for editing.

NOTE: You have now completed a 98% verification of Meter Function.

• Before making changes, Save the Initial Settings as Initial Settings.NPS* on hard drive by clicking Save.

• Click on the Group (+/-) icon, double-click the selected parameter. The screen appears. Make changes. Click OK. Then use buttons at the bottom of the screen to UPDATE DEVICE, SAVE, LOAD, print a REPORTor CANCEL. Section 1.5 reviews primary screens.

• SAVE the new NPS File as Modified Settings.NPSor as a unique name to identify the file (Unique System ID or Customer’s Name, for example).

• To implement changes, click UPDATE DEVICE.• To LOAD a new or different file, select a file name.• RESET ALL LOGS in Main screen > Tools > Reset.

1.5: Device Profile Screens

General Settings

• CT and PT Ratios and System HookupAny change to CT settings will automaticallyupdate the corresponding Full Scale value in the Limit and Waveform Full Scales settings and will effect all other settings.

NOTE: Chapter 4 of the Nexus Communicator EXTUser Manual has a detailed description of program-ming options for Nexus 1262/1272.

If you are using Block Demand, Transformer Loss Compensation, other than 15 minute demand or Load Profile Recording (Trending) the default values should be changed.

NOTE: Be sure to set the CT and VT ratios to values that are correct for the installation site.


• Limit and Waveform Full Scales These settings are based on a percentage of Full Scales, which are derived from the CT Ratios and can be changed without effecting accuracy. Be sure to set CT Ratios first.

• Time Settings(Initial Setting is - 5:00 Eastern Time)- 6:00 = Central Time - 9:00 Pacific Time- 7:00 = Mountain Time -10:00 Hawaii- 8:00 = Pacific Time -11:00 Midway IslandAuto DST (Daylight Savings Time) is Enabled.

• Communications SettingsPorts 1 and 4 are programmable. Port 4 is INITIALLY SET forExternal Devices and can be changed.

For Internal Modem and Network Options, set Advanced Settingsand Dial Out Profile.

For INP102, the Advanced Settings button accesses the group of screens shown here. Click the INP102 tab.

When settings are complete, click OK to return to the Communications Settings screen.

Click OK to return to Main screen.


Revenue & Energy Settings

• Block Average DemandInput settings for Demand Integration. Click OK.

• Display Configuration - Assign Screens Use pull down windows to set up Display Modes & Screens.

Power Quality & Alarm Settings

• LimitsDouble-click on a column or setting, change setting. Click OK.

• Waveform - CBEMA ProfileTriggers for waveforms are set here based on a percentage of Full Scales (set on the Limit &Waveform Full Scales screen).

Set Sampling Rate and Total Captures.

Click OK.


Trending Profile Settings

• Trending Log Time IntervalsSet Intervals for Time Stamps from 1 second to 18 Hours. Based on Nexus time. Click OK. Time is set in the Tools Menu.

• Trending Setup for Historical LogsUsing pull down menus, select Type of Snapshot and Channel. Click Add or Remove.

A running Total of Bytes Used appears on the screen.

Click OK.

1.5.1: Save the New ProgramClick the SAVE Button on the Device Profile Screen and give your new program an identifiablename.

1.6: Field InstallationYou now have a tested meter with a program for the site where it will be installed. Meter installationis like any other meter of that Form. See Chapter 11 of this manual for Wiring Diagrams.

Electro Industries/GaugeTech Doc # E151-7-01 V1.01 2-1

Chapter 2Nexus 1262/1272 Overview


2.1: The Nexus 1262/1272 Multiparameter Power Meter

The Nexus 1262/1272 transformer-rated, polyphase meter is a unique collection of metering technologiesto fulfill advanced metering requirements. It provides high-accuracy power and energy measurements ofvoltage, current and all power values, data logging and power quality recording. The unit makes the dataavailable through the display, connected systems and historic logs.

2.2: Accu-MMeasure© Technology - Theory of Operation

The advanced metering capability of the Nexus 1262/1272 is a result of EIG’s Accu-Measure© DigitalSensing Technology. Accu-Measure© is a combination of high-speed sampling, high-resolution measurement and high-speed calculation. All voltage and current waveforms are sampled and RMS values calculated continuously every cycle. Values of voltage, current and power are produced everythree cycles and every second.

Figure 2.2 illustrates the key processes operating within the Nexus 1272. The meter allows for fourtypes of inputs and can provide outputs to an integrated display, pulse outputs and several communication ports. Nexus 1262 is illustrated in Figure 2.3.

Voltage and current signals enter the meter and are sampled at up to 256 samples per cycle. Each sampleis resolved to a digital value using 16-bit analog-to-digital converters. Two 16-bit A/D converters areused for the 1272 (one for 1262). The first is for the real-time measurements. The second is for thewaveform recorder. The use of two A/D converters ensures that both signals have maximum resolution,accuracy and integrity. The second also isolates energy sampling and calculations from the waveformfault recording requirements. This provides both advanced energy and advanced waveform analysis.

Mode (Reed)Switch

Infrared TestPulse

Reset Switch

Form FactorDiagram

ExampleScreen

Bar Code

Optical Port

Test ButtonUnder Cover


Figure 2.2: How the Nexus 1272 Processes Inputs

The digitized signals are then passed to the appropriate processor. Real-time measurements are calculated in one processor and made available for meter readings and historical logs. A separateprocessor performs waveform recording. Calculated data and logs are stored in memory for delivery todisplays, external systems and download processes.

The meter includes a time synchronizing input port that accepts an industry standard IRIG-B signal tosynchronize meter time to standard universal time. If there is no IRIG-B signal, the meter uses a timesynchronizing input port that uses line frequency to synchronize meter time to standard universal time.The Line Synchronization Feature may be Enabled or Disabled. If it is not Enabled, the Internal Clockprovides time sychronization. All readings and logs are time stamped to the nearest millisecond.

Eight status channels provide input of status or pulse signals. Status inputs are date/time stamped to thenearest millisecond and placed in the event log. Pulse inputs are multiplied by a user-supplied factorand accumulated in reading registers. These accumulated values can also be totalized. This featuremakes the Nexus 1272 a good fit in universal metering applications. Any one input channel can beselected to accept an End of Interval pulse from another meter.

Meter set-up parameters and all historical log data are stored in nonvolatile RAM. The user has multiplelog functionality. Data is made available through the onboard display. Display screens are described insection 2.3.3. Several additional communication channels operate simultaneously, including the optionalEthernet/Modem Combo Card.. External systems can be connected to either of the RS-485 ports or theEthernet/Modem port. Stored data can be downloaded through the RS-485 ports, the Ethernet/Modemport or the IR port.


Figure 2.3: How the Nexus 1262 Processes Inputs

The meter includes a time synchronizing input port that uses line frequency to synchronize the metertime to standard universal time. The Line Synchronization Feature may be Enabled or Disabled. If thisfeature is not Enabled, the Internal Clock provides the time sychronization. All readings and logs aretime stamped to the nearest millisecond.

Nexus 1262 does not have status input channels and does not have a CBEMA Log or Waveform recording.

Meter setup parameters and all historical log data are stored in nonvolatile RAM. The user has multiplelog functionality. Data is made available through the onboard display. Display screens are described insection 2.3.3. Several additional communication channels operate simultaneously, including the optionalEthernet/Modem Combo Card (separate connections that can be used simultaneously). External systemscan be connected to either of the RS-485 ports or the Ethernet/Modem port. Stored data can be downloaded through the RS-485 ports, the Ethernet/Modem port or the IR port.


2.3: Advanced Measurement Functionality

2.3.1: Advanced Revenue Billing Capability

The Nexus 1262/1272 is a full four-quadrant power meter with accuracy of within 0.06% of reading.Energy measurements include: kWh Delivered & Received, kVARh Delivered & Received, kVAh,kVARh, kWh in each quadrant and Total kVAh. It measures instantaneous power and provides multiple, simultaneous demand measurements, including time-stamped maximum and minimum readings.

Time of UseThe Nexus 1262/1272’s Time of Use functionality offers the following standard capabilities:

• 8 TOU Schedules• Bidirectional Consumption and Demand• 4 Seasons/Year• 20 Year Calendar• Prior Month and Prior Season Readings for each Schedule• Present Month and Present Season Readings for each Schedule• Total to Date Readings for each Month• Total to Date Readings for each Season• Cumulative and Continuous Cumulative Demand

Load Aggregation/ Universal MeteringUsing standard pulse inputs, the Nexus 1272 can count pulses from external meters and accumulate usage. The pulse inputs can be used to totalize electrical usage and utility values, such as water or gas use data. Readings include:

• 8 Pulse Inputs• Individual Accumulating Registers• 4 Totalizing Registers• Totalize with Nexus kWh Readings

Multiple Demand WindowsThe Nexus 1262/1272 simultaneously monitors four demand structures. The unit offers:

• Block Window Demand• Rolling Window Demand• Predictive Demand• Thermal Demand• Interval Length from 1 second to many hours• Up to 15 Sub-Intervals• End of Interval Pulse Output (with Optional 4IPO Internal KYZ capability)• End of Interval Pulse Input

Time Stamped Max/Min DemandsThe unit gathers Time Stamped Max/Min Demands for all power values. Each of the following values is date/time stamped:

• kW Demand, Delivered & Received, Max/Min• kVAR Demand, Delivered & Received, Max/Min• kVAR Coincident with kW Demand• kVA Demand, Max/Min• Amps Demand, Max/Min• Voltage Demand Max/Min


Transformer Loss CompensationTransformer Loss Compensation adjusts for both copper and iron losses with a simple user setup.

2.3.2: Advanced Communications and I/O Capabilities

The Nexus 1262/1272 features advanced communication which utilizes multiple com ports using open protocols. Nexus’ multi-port design allows multiple communication connections simultaneously. TheNexus 1262/1272 System provides a direct digital link to your customer, allowing them to gather selected data without effecting the meter or your data. All of the advanced features of the 1262/1272 aremade available through industry-standard Modbus and DNP 3.0 protocols. No proprietary or closed pro-tocols are used.

Standard Communications• ANSI Type 2 Optical Port (IR Port)• 2 RS-485 Serial Ports• Modbus RTU/ASCII Protocol• DNP 3.0 Level 2 + Protocol• Speeds up to 115k bps

Optional CommunicaionsThe Nexus 1262/1272 allows you to select an additional port for one of the following uses:

• INP2: Internal 56k Modem with noise rejection• INP100: Internal Ethernet TCP/IP (10/100BaseT) with multiple sockets and Modbus TCP

Server Functions• INP102: Combination 56k Modem and Internal Ethernet TCP/IP (10/100BaseT)

Standard Internal I/OExtensive I/O capability is available in conjunction with all metering functions.

• IRIG-B Time Synchronizing to GPS to 1 millisecond resolution.• 8 High-Speed Status Inputs for status detect or of load aggregation/universal metering

inputs.• Line Frequency Time Synchronization

Internal I/OThe Nexus offers four optional KYZ Pulse Outputs which can be programmed to pulse for any accumulated reading. One of the pulse outputs can also be set for an End-of-Interval Sync Pulse.Upgradeable External I/OThe user can select from the following to connect multiple external I/O Modules for enhanced I/O capability.

• Analog Outputs• Analog Inputs• Additional Status Inputs• KYZ Outputs• Relay/ Alarm Outputs

Control Options• ElectroLogic provides user-definable control outputs.• Action and/or alarm on Abnormal Condition.• Action on Boolean Logic Combinations of Inputs or Electrical Conditions.


2.3.3: Flicker

The Nexus 1272 provides Flicker Evaluation in Instantaneous, Short Term and Long Term forms. For adetailed explanation of Flicker, see Chapter 14 of this manual.

2.3.4: Display Screens

The Nexus 1262/1272 features a built-in graphical back-lit FSTN LCD display with extended temperature voltage compensation. This allows you to view energy data and to gather circuit diagnostic data such as voltage, current, harmonics and phasor information. This displayis easily programmable. An example of a programmed screen is shown here. The ProgrammableDisplay is covered in detail in Chapter 3 of this manual.

2.3.5: Additional Switches

The Nexus 1262/1272 has additional switches & signals that help in using the unit (Fig. 2.1).• The Infrared Test Pulse can be set to pulse for +Watt-hour, -Watt-hour, +VAR-hour,

-VAR-hour and VA-hour. The pulse uses a time-modulated pulse integration which allows the pulse to be accurate during short duration pulse tests. The pulse integration uses industry-accepted reference standards.

• The Mode Switch (magnetic reed switch) uses a magnet to switch operating modes.• The Test Button.• The Reset Button.

2.3.6: Nexus External I/O Modules

A variety of optional analog or digital I/O modules mount externally to the Nexus 1262/1272 SocketMeter. The Nexus 1262/1272 Unit DOES NOT SUPPORT I/O MODULES. Use a power supply, suchas EIG PSIO, to provide I/O capability. See Chapter 10 for details on installation and usage of theNexus External I/O Modules.

2.3.6.1: Optional P40N LED Remote Display

The Nexus 1262/1272 Socket Meter features a back-lit LCD display built into the face of the meter. Inaddition, Electro Industries offers two optional external displays, each powered by a power supply (suchas the PSIO). The P40N is the LED display which provides easy-to-use access to information stored inthe Nexus where an additional display is required for remote access. See Chapter 9 for further details.

2.3.6.2: Optional P60N Touch Screen Remote Display

The P60N is the Touch Screen Display which also provides easy access to Nexus readings and datawhere an additional display is required and this data is offered in a graphical touch screen presentation.The P60N also requires an additional power source, such as the PSIO. See Chapter 9 for further details.


2.4: Nexus 1262/1272 Forms

The Nexus 1262/1272 offers four supported S-Based Meter Forms based on the rated voltage and hookup required by the user. Below are the form specifications. See Chapter 11 for corresponding wiring diagrams and Appendix B for Blade Configurations. For Z-Based Forms, see Chapter 12.

NOTE: Form 45S replaces Form 5S and may also be used in 4-wire circuits.

Nexus 1262/1272 Forms

Nexus 1262/1272 Accuracy

Form Rated Voltage Hookup

9S (120 to 480)Vdc 3E, 4W, Wye or Delta

36S (120 to 480)Vac 2 1/2E, 4W, Wye

39S (120 to 480)Vac 3E, 4W, Wye with Neutral

45S (120 to 480)Vac 2 1/2E, 4W Wye or 3W Delta

Value Accuracy

Voltage 0.02%

Current 0.05%

Frequency 0.001Hz

kW 0.06%

[email protected] 0.06%

[email protected] 0.10%

kVAR 0.10%

kVA 0.10%

PF 0.10%


2.5: Nexus 1262/1272 Specifications Overview

Input Voltage• Rated 120 to 277 Volts line-to-neutral; 120 to 480 Volts line-to-line.• Operating 96 to 332 Volts line-to-neutral; 155 to 576 Volts line-to-line.Input Current• Three or four current inputs depending on form (IA, IB, IC and IN).• CT Rated 0-20 amps.• Defined as Class 20 (Class 2 and Class 10 Available).• Transformer Rated Continuous 120% of meter class.• Overload 500% for 1 second, non-recurring.Frequency• 45-62 Hz.Burden (Sense Inputs)• Voltage Inputs: 0.33VA@576V.• Current Inputs: [email protected]• All inputs and outputs isolated to 2500 Volts. • Com Ports isolated from each other to 1000 Volts.Sensing• Accu-Measure© Technology.• 2x16-bit A/D converter (1272). 1x16-bit A/D Converter (1262).• True RMS.• 8-Channel Sample and Hold.Memory• All meter setup parameters, measurements and logs contained in nonvolatile RAM.Compliance• ANSI C12.20 Class 0.2 and IEC687 (Accuracy).• ANSI C37.90.1 (Surge Withstand).• ANSI C62.41 (Surge Immunity).• ANSI C12.18 (Optical Port).• IEC 61000-4-15 (Flicker) (1272).Standard Communications• LCD Display.• ANSI Type 2 Optical Port (IR Port).• Two RS-485 Serial Ports.• Modbus RTU, Modbus ASCII and DNP 3.0 protocols.• Data Speeds of up to 115k bps.Optional Communications• INP2: Internal Modem with data buffering for faster downloads and noise rejection.• INP2: Connect speeds of 300 to 56k bps.• INP100: Internal 10Mbit Ethernet with multiple socket support which is Modbus TCP/IP Web

Ready.• INP102: Ethernet (INP100) / Modem (INP2) CombinationInternal 8-Channel Digital KYZ Pulse/Status Inputs• Type: Self-excited, for dry contacts only.• Wetting Voltage: 12Vdc typical.


Internal 4-Channel KYZ Outputs• Type: Form C.• On Resistance: 23-35Ω.• Peak Voltage: 350Vdc.• Continuous Load Current: 120mA.• Peak Load Current: 350mA (10ms).• Off-State Leakage Current @350Vdc: 1 µA.• Opto Isolation: 3750Vrms (60 Hz, 1 min.).Timing• IRIG-B input for synchronizing to external GPS clock signal.• Line Frequency Synchronization.• Internal Clock.Environmental• Operating Temperature: (-40 to +85)°C.• Display Operating Temperature: (-20 to +70)°C.• Humidity: 95% non-condensing.• Storage Temperature: (-40 to +85)°C.• Lexan Cover.Power Supply (Unit is powered by 3-Phase Voltage Sense Inputs.)• (96 to 550)Vac 50/60Hz (576Vac absolute maximum), Autoranging 3-Phase Power Supply.

Meter power requirement 3VA/Phase @ 120Vac worst case.• Meter power provided by any of the 3-Phase voltage sources being monitored.Aux Power Supply Option (Unit is powered by Aux Pigtail Wire.)• Select Power Supply Option “SE” in ordering information.• Input Voltage: (120 to 230)Vac (±20%) 50/60Hz (125 to 400)Vdc.• Maximum Power Consumption: [email protected]• Hardware lock secures meter settings.• Two 10-character passwords.• One password controls access to read meter digitally.• Separate password controls access to program meter.Internal Battery• Panasonic BR2032 3V Lithium Battery (or equivalent) maintains NVRAM and time during

outages.Modem Battery• 3V Lithium Battery with custom leads and velcro mounting maintains Dial-Back Feature during

outages. Call factory for replacement battery.


2.6: Nexus 1262/1272 Logging Specifications

Logging Specifications Footnotes

1. Assuming Log is storing 4 readings every 15 minutes.2. Number of Events Recorded (assumes 14 parameters monitored).3. Number of Waveform Records. Each record may be from 8 to 64 cycles in duration, depending

upon meter setup.

2.7: DNP V3.00 Level 2

Nexus 1262 and 1272 support DNP V3.00 Level 2.

DNP Level 2 Features:• Up to 136 measurements (64 Binary Inputs, 8 Binary Counters, 64 Analog Inputs) can be

mapped to DNP Static Points (over 3000) in the customizable DNP Point Map.

• Up to 16 Relays and 8 Resets can be controlled through DNP Level 2.

• Report-by-Exception Processing (DNP Events) Deadbands can be set on a per-point basis.

• Freeze Commands: Freeze, Freeze/No-Ack, Freeze4 with Time, Freeze with Time/No-Ack.

• Freeze with Time Commands enable the Nexus meter to have internal time-driven Frozen and Frozen Event data. When the Nexus meter receives the Time and Interval, the data will be created.

For complete details, download the appropriate DNP User Manual from our website www.electroind.com.

Model Memory HistoricalLog 11

HistoricalLog 21

CBEMA/ITIC2

EventLog2

WaveformLog3

OutputLog2

InputLog2

1272 Standard 85 Days 133 Days 512 1024 63 256 1024

1272 Advanced 555 Days 133 Days 512 1024 95 256 1024

FlickerLog2

1536

5120

SystemEvents2

1024

1024

Model Memory HistoricalLog 11

HistoricalLog 11

CBEMA/ITIC2

EventLog2

WaveformLog3

FlickerLog2

OutputLog2

InputLog2

SystemEvents2

1262

1262

Standard

Advanced

69 Days

480 Days

32 Days

133 Days

N/A

N/A

512

512

512

512

1024

1024

1024

1024

N/A

N/A

N/A

N/A

Chapter 3Operating Instructions for Nexus 1262 & 1272

3.1: Nameplate Information

The Nexus 1262/1272 Socket Meters have their operating information represented on the nameplate, which is located on the face of the meter. See Figure 3.1 below for a graphical representation of the 1272 meter nameplate. Serial and Model Numbers are on the Options Label (see below).


Figure 3.1: Nexus 1272 Nameplate

KEY: The numbered list below acts as a key for the label above:

1. Multiply by Constant 6. Test Amperes2. Voltage Transformer Ratio (or PT Ratio) 7. Watt-hour test constant3. Current Transformer Ratio (see Glossary) 8. ANSI C12.20 Form Number4. Primary Watt-hour constant 9. ANSI C12.20 Accuracy Class5. Current class

5 6 8 9

1

2

3

4

7

Graphical LiquidCrystal Display

Form FactorDiagram

ModeSwitch

User Defined Area

PERFORMANCEENHANCED

The Options Label is adhered to the outside of the internal shroud. It is prepared specifically foreach meter showing the ordered options that are included in the meter. The label above is an example of a typical label without the numbers. Below is a list of options available for the meter:

• Memory (1272): Memory (1262)

S (Standard) 2M of RAM S (Standard) 512K of RAM

A (Advanced) 4M of RAM A (Advanced). 2M of RAM

• Input and Output Modules:

8AI1 8 Analog Inputs, 0±1mA 1mAON4 4 Analog Outputs, 0-1mA8AI2 8 Analog Inputs, 0±20mA 1mAON8 8 Analog Outputs, 0-1mA8AI3 8 Analog Inputs, 0±5Vdc 20mAON4 4 Analog Outputs, 4-20mA8AI4 8 Analog Inputs, 0±10Vdc 20mAON8 8 Analog Outputs, 4-20mA8DI1 8 Digital Status Inputs 4RO1 4 Relay Outputs

4PO1 4 Solid State Pulse Outputs

• Communication Options:

INP2 - Dial Out OptionINP100 - Ethernet 10/100BaseTINP102 - Ethernet/Modem Combination

• EIG Number: Model Number plus Option Numbers: (Example below)

Model - Memory - Form - Freq - Power Supply - I/O - Communication1272 - A - 9S - 60Hz - S - 4PO1 - INP100



3.2: Basic Operations

Figure 3.2: Nexus 1262/1272 Switches and Indicators

Switches and Indicators

There are two switches accessible from outside the meter cover.

1. The Mode Switch (also called a Reed Switch) is used to switch from Normal Mode toCircuit Diagnostic Mode or Time of Use Mode.

2. The Reset Switch is used to reset demand.

A third switch, the Test Button, is accessible only when the cover has been removed. The TestButton switches the meter from one of the operational modes to Test Mode and back to NormalMode. The Test Button is also used to access Display Adjustments Mode during Powerup Mode.The Display Adjustments Mode is discussed in section 3.5.

The Optical Port is on the lower left side of the face. The Optical Port facilitates infrared communication with the meter. Using a SC-1A Smart Coupler (or other ANSI C12.13 Type II magnetic optical Communications coupler) and an RS-232 cable from the Smart Coupler to a PC,you can program the meter with Communicator EXT software.

An Infrared Test Pulse is located on the upper left side of the face. Energy pulsing applications canbe configured using Communicator EXT software.

A Phase Indicator is located on the lower right side of the face. “ABC” will stay illuminated if allthree phases of voltage and current are present. “ACB” indicates reversed phase sequence. It willblink A, B or C if one phase is not present. If all phases are not present, the meter will turn off(unless you have an Aux pigtail connected to a power source).

Mode (Reed)Switch

Activate Mode(Reed) Switchwith a Magnetswiped on theside of themeter.


Reset Switch

InfraredTest Pulse

Optical Port

3.3: Display Information

The Nexus 1262/1272 uses a graphical back-lit FSTN LCD Programmable Display with extended temperature voltage compensation. This allows you to view energy data and to gather circuit diagnosticdata such as voltage, current, harmonics and phasor information.

A wide range of values can be defined for display using the User Modes and screens in theProgrammable Display and Communicator EXT software. Three View Modes plus Test Mode and aSelect Compensation Screen allow tremendous flexibility in setting up the Modes and the screens within the modes. View Modes are user created with up to 16 screens each, which display in autosequence every 7 seconds. Most of the screens have a Status Bar across the bottom which displays thedate, time and phase (if there are inputs). View Mode 1 is the primary mode. The other modes willautomatically return to View Mode 1 after a user-set amount of time from last user action.

Low Battery• Lo Batt - NVRam (Internal Battery) or Lo Batt - Modem (Modem Battery) will flash on

the screen being displayed every 10-15 seconds ONLY when the Internal (or Modem) Battery is running low or when it is not “clicked” into place properly. If the batteries are not low, NO INDICATOR will appear.See installation instructions in sections 6.2 and 6.2.1.

Test Mode• Wh Test - Same as kWh screen, except in Wh instead of kWh• VARh Test - Same as kVAR screen, except in VARh (Quadrants)• VAh Test - Same as kVAh screen,except in VAh (Quadrants)• Watt Rolling Demand Test (Delivered and Received)• Watt Block Demand Test (Delivered and Received)

Initial Display ScreensThe Nexus 1262/1272 is shipped with Initial Display Screens, which will scroll on the display assoon as you power up the meter. The Initial Display Screens are a sampling of the many screensavailable for the Programmable Display, which is detailed in sections 3.4 to 3.7.

Typical Initial Display Screens:Meter Data, including Boot, Run, DSP Boot, DSP Run, Serial Number, Protect Enabled, Baud

Wh Delivered Wh ReceivedkVARh per Quadrant kVAh per QuadrantRolling W Demand Delivered Rolling W Demand ReceivedBlock W Demand Delivered Block W Demand ReceivedW Demand Last Reset Cumulative W Demand

BacklightThe Backlight cannot be set to stay on indefinitely. It will turn off after the amount of time selected.One hour is the maximum setting. If the backlight has timed out and is off, you need to hit the Mode Switch once to turn on the backlight and redirect the screen automatically.



3.4: Nexus 1262/1272 Programmable Display Navigation Map


3.5: Programmable Display Overview

The Programmable Display has three configurable User Modes with up to 16 screens each. Thethree modes are displayed in auto sequence every 7 seconds. Using Communicator EXT, the user canassign up to 16 screens to each mode and any of the available screens can be used in any mode. Theuser also assigns a three-digit label that names the mode. The three modes are:

•• Configurable View Mode 1 - Replacing Normal Mode•• Configurable View Mode 2 - Replacing Circuit Diagnostic Mode•• Configurable View Mode 3 - Replacing Time of Use Mode

This feature is very user-friendly and enables the user to determine what data will be displayed and in what order. This feature highlights larger (.56”) digits on many of the screens so that data displayed is much easier to read.

View Mode 1 is the primary mode. The other user modes, View Mode 2 and View Mode 3 are accessed by swiping the Mode Switch twice. Test Mode is accessed by removing the cover(POWER MUST BE OFF), powering up the meter and pushing the Test Button at any time.

View Mode 2 and View Mode 3 will automatically return to View Mode 1 after a user-set amount of time after the last user action. Test Mode will automatically return to View Mode 1 after an amount of time after the last user action with no energy accumulation (or) an amount of time after the last user action plus the demand interval with energy accumulation. The values for the amount of time after the last user action is set on the Miscellaneous screen in the User Inactivity Time Outs section.

The Programmable Display can be edited through Communicator EXT even if the meter is not connected to the computer. Simply click File > Open > Nexus Programmable Display Profile as shown here. The set of programming screens will appear so that changes can be made. The programming screens are detailed below in section 3.6.

See the Communicator EXT User Manual for details on programming the Nexus 1262/1272 andretrieving data.


3.6: Programmable Display Setup

The steps to setup the ProgrammableDisplay are simple:

1. Click Tools > Edit LCDProgrammable Settings.

The following set of screens (Nexus Display Programmable Settings) appears.

2. Click the Meter Display Mode Names Tab.

Enter a three-letter label for each of the three View Modes.

Enter a description for each mode using the Line 1 and Line 2 Description windows.

3. Click on the Screen Assignments tab.

4. Double-click on the screen you want to change.

5. Enter up to 16 screens under each mode on the Screen Assignments screen.

Your Label for each mode will appear at the top of each column.


5. Click on the Power and Energy Display tab. Enter settings for Power and Energy:

Scale: select from Units, Kilounits, Megaunits.

Number of Digits: 4 - 9 (Primary Power).

Decimal Point Location:0 - 3 (Primary Power)

Check Display Leading Zeroes, if desired.

Previews appear at the bottom of the screen.

Settings on this screen control the display of energy related numbers. Care should be given to matchthe values on the display with those in the historical logs. These settings apply to VA-hours, watt-hours(+/-), VAR-hours (+/-) and VAR-hours (each quadrant) in the meter.

Scale Factor is the user-programmable setting that determines what quantity is used in the energy-type registers. Scale Factor applies to primary values ONLY. (Secondary values are alwaysin units.) Scale Factor can be set to: Units, Kilounits or Megaunits.

Scale Factor takes precedence over all other settings, i.e., all other settings are based on this setting.

The Number of Digits Displayed is user-programmable between 4 and 9. This setting controls onlythe display and storage of all digits displayed and it sets the Register Rollover for all energy-typeregisters.

Example: If the Scale setting is Megaunits and the Number of Digits Displayed is 5, the displaywill show up to 99,999 megawatt-hours and associated registers will rollover at 99,999 megawatt-hours.

6. Click on the Miscellaneous tab. The Screen settings replace Adjustments Mode in the default profile.

7. Enter settings in the Miscellaneous screen:

Screen Settings (on the Miscellaneous Screen):Back Light Level: 0-Off to 4-Brightest

Back Light Time (Back Light shuts off): 00min, 30sec - 60min, 00sec

Contrast: 0 - Highest to 7 - Lowest


Scroll Stop: Enabled orDisabled

Phasor Rotation:Clockwise or Counterclockwise

Demand Shown: Cumulative orContinuous Cumulative

Time of Use Demand:Block/Rolling orCumulative

Date Format:Month/Day/YearDay/Month/Year

Optical Port:Baud Rate: 1200, 2400, 4800, 9600, 19200, 38400 or 57600Optical Receive: Normal or Inverted

User Inactivity Time Outs (number of minutes since last user action when Mode reverts to View Mode 1) (Settings are 5 to 60 minutes with 1 minute intervals.):Leave Test Mode After _ Minutes: Reverts with or without energy accumulation.Leave View Mode 2 After _ Minutes: Reverts automatically.Leave View Mode 3 After _ Minutes: Reverts automatically.

8. Use Buttons for Functions below:Update Display: Click to send the new settings to the display.

(After settings have been updated, View Mode 1 is displayed.)Retrieve from Display: Click to Retrieve existing settings.Cancel: Click to Cancel any new settings, return to main Communicator EXT screen.Save: Click to Save new settings to a file.Load: Click to Load saved settings from a file.Help: Click to get Help for this set of screens.

9. When finished making any changes, click Update Display to send the new settings to the display. Pop-up windows will tell you that the changes have been made and you will return to the main Communicator EXT screen.


3.7: Programmable Display Screens

The Nexus Programmable Display screens have some features that make them very user friendly:

1. Many of the screens have larger digits (.56”) which are more legible. 2. There are more screens from which to format your data. 3. The Polling Indicator in the right corner of the Status Line provides two functions:

A. A blinking indicator shows that the display is receiving data from the meter.B. Power Flow is displayed by different shaped icons.

1. When no power is flowing, a solid block is displayed.2. An animated arrow pointing RIGHT indicates positive power flow.3. An animated arrow pointing LEFT indicates negative power flow.

4. Modifiers enhance the flexibility of some screens. See section 3.7.1.

Below is a list of available screens with some example screens:

Screen ScreenNumber Name

1 Wh Delivered2 Wh Received3 +VARh4 -VARh5 VAh11 Rolling W Demand Del12 Rolling W Demand Rec13 Block W Demand Del14 Block W Demand Rec15 W Demand Last Reset16 Phase to Neutral Voltage17 Phase Current18 Phasors20 VAR, PF, Frequency21 Va, Vab Harmonics22 Vb, Vbc Harmonics23 Vc/Vca Harmonics24 Ia Harmonics25 Ib Harmonics26 Ic Harmonics45 Totalizer 146 Totalizer 247 Totalizer 348 Totalizer 449 Totalizer 1 Demand50 Totalizer 2 Demand51 Totalizer 3 Demand52 Totalizer 4 Demand53 Cumulative Demand, Del & Rec


54 Phase to Phase Voltage55 W56 VAR57 PF58 VA59 Frequency60 Segment Check61 Q63 Meter Name64 Optical Port65 Com Port Settings66 Nexus Ststus67 Firmware Versions68 Nexus Info69 Average PF Received (Modifier 7)70 Average PF Delivered (Modifier 7)71 VARh per Quadrant (Modifier 1)72 VAh per Quadrant (Modifier 1)73 Wh per Quadrant (Modifier 1)74 Qh (Modifier 3)75 Cumulative Demand (Modifier 2)76 Rolling Window Demand (Modifier 4)77 Block Window Demand (Modifier 4)78 Power Factor per Phase (Modifier 6)79 Power Factor per Quadrant80 TOU Wh, Rec (Modifier 5)81 TOU VAh, Q1 (Modifier 5)82 TOU VARh, Q1 (Modifier 5)83 TOU VAh, Q4 (Modifier 5)84 TOU VARh, Q4 (Modifier 5)85 TOU Wh, Del (Modifier 5)86 TOU VAh, Q2 (Modifier 5)87 TOU VARh, Q2 (Modifier 5)88 TOU VAh, Q3 (Modifier 5)89 TOU VARh, Q3 (Modifier 5)90 TOU W Demand, Rec (Modifier 5)91 TOU W Demand, Del (Modifier 5) 92 TOU + VAR Demand (Modifier 5) 93 TOU-VAR Demand (Modifier 5)

NOTE: Refer to Programmable Display Screen Modifiers in section 3.7.1.


3.7.1: Programmable Display Screen Modifiers

Many of the Nexus Programmable Display screens have Modifiers that create variations of the basicscreen, if utilized. Below is the list of the modifiers:

Modifier Enumeration1. Quadrant 1-4 Quadrant 0 - 3 (Q1 - Q4)

2. Del or Rec b0 = Rec, b1 = Del

3. + or - b0 = +, b1 = -

4. Del or Rec W Enumeration 0 = VA+ or - VAR 1 = + VARVA 2 = - VAR

3 = Rec W4 = Del W5 - 8 Unassigned (same as VA)

5. Register & Period RegisterPeriod 0 = Frozen 0-7 = R1 - R8

1 = Prior Month 8 = Total2 = Active 9-15 = Unassigned (same as Total)3 = Current Month

6. Inst or Avg b0 = Instantaneous (1 sec)b1 = Average

7. Avg or Max b0 = Average b1 = Maximum

8. N/A or none 1


Chapter 4Testing for Nexus 1262/1272

WARNING!The information contained within this chapter is intended to be an aid to qualified metering personnel. It is not intended to replace the extensive training necessary to install or remove metersfrom service. Any work on or near energized meters, meter sockets or other metering equipmentpresents the danger of electrical shock, personal injury or death. All work on these products mustbe performed by qualified industrial electricians and metering specialists ONLY.All work must be done in accordance with local utility safety practices and the procedures outlinedin the current edition of the Handbook for Electricity Metering. The handbook is available from the Edison Electric Institute, 701 Pennsylvania Avenue N.W., Washington D.C. 20004-2696.

4.1: Testing Tools

The Nexus 1262 and 1272 are equipped with a light-emitting diode (LED) for calibration and a liquid crystal display with test screens. These two standard features provide user interface andequipment interface points for meter testing.

4.1.1: Test Pulse LED

The Test Pulse LED is located in the upper left-hand portion of the meter face as shown in Figure4.1. The Test Pulse LED continuously emits calibration pulses (infrared light). This LED can beused for a variety of pulses including: Individual quadrants for Watthour, VAhour, VARhour andcombined Watthour pulses. Each calibration pulse is equal to the value assigned to Kt (Watthoursper pulse) in the meter’s Device Profile. The millisecond duration of each output pulse is also programmable in the meter’s Device Profile.


Reset Button

InfraredTest Pulse

Optical Port



To program the Test Pulse LED, go to the Device Profile in Communicator EXT, click on KYZOutputs then click on any of Test LED pull-down menus to configure the following settings:

1. Assigned Channel - choose from settings.2. Watthour per Pulse - enter the value in the secondary.3. Pulse Width - can be set from 5ms to 635ms.4. Mode - can be enabled or disabled.5. Form - can be selected between Form A and Form C.

Click OK. Then click Update Device to send the new settings to the meter.

The unit for the calibration pulses is Watthours. The initial value of each pulse (Kt) is 1.800 secondary Watthours per pulse.

4.1.2: LCD Display

In Test Mode, the LCD display provides user access to accumulated real, reactive and apparent energy as well as block demand for real power. There are seven screens in Test Mode: Wh - Del& Rec, VARh - Q1 & Q2, VARh - Q3 & Q4, VAh - Q1 & Q4, VAh - Q2 & Q3, Block Average TotalWatt and Rolling Average Total Watt. See section 4.2.2 for more detail.

The LCD display also includes three phase voltage annunciators. These annunciators are labeled A,B and C to indicate the presence of voltage on the indicated phase. If voltage is not present on onephase, its indicator will not be displayed. These indicators also show whether current is flowing onthe indicated phase. If no current is flowing on a phase, the annunciator will blink. When current isflowing, it will show a continuously illuminated digit. This annunciator indicates phase sequence.

4.2: Test Mode

Test Mode allows the meter to be tested without disturbing billing data or setting a new maximum demand. Test Mode performs the same function as setting the pointers back on anelectromechanical meter after testing.

While operating in Test Mode, the meter uses the same measurement and calculation processes thatare used in Normal Mode. The only difference is that the billing numbers stored in the meter are notupdated with the real-time reading. This preserves the billing numbers while testing is performed.

4.2.1: Entering Test Mode

To enter Test Mode, the user must pass the meter’s security system. In most instances, this requiresthe user to break the meter seal and remove the Lexan cover. In the lower right hand quadrant of themeter face there are two push buttons. Pressing the button on the right for more than one secondwill place the meter in Test Mode. When this occurs, the display will change to indicate the user hasentered Test Mode (the word Test in the lower right corner of the screen).


Upon entering Test Mode, various things occur:

1. All energy, demand and TOU values are stored in nonvolatile memory in the meter.2. Meter log recording is suspended; historical logging continues and entries to historical logs

reflect that Test Mode is in effect during the effected interval(s).

4.2.2: Using Test Mode

The same selected measurement profile quantities (data accumulations) that are calculated duringnormal operation are calculated in Test Mode. Display quantities (Watt-hour, VAR-hour, Volt-Ampere-hour and Block Demand quantities) are displayed in units rather than kilo-units; i.e. thedata is displayed as Wh, VARh, VAh and Watts rather than kWh, kVARh, kVAh and kW. Thesame demand values calculated during normal operation are also calculated in Test Mode. The display formats in Test Mode are changed to provide greater resolution during test operations.

The display does not scroll while in Test Mode. Each item remains displayed until the Test ModeButton is pressed. At that time, the next Test Mode screen is shown.

The following table shows the display screens available in Test Mode and the data displayed on eachscreen and the pulse source for each screen:

Adjacent to the Test Mode Button (T) is the Reset Button (R). A Test Reset is initiated by pressingthe Reset Button while in Test Mode. A Test Mode Reset causes all test quantities to be reset to zeroand a new block interval to be started. The item displayed when the reset occured remains in thedisplay but the value will be initialized. The reset occurs when the Reset Button is released.

Wh - Del & Rec Delivered Wh EnergyReceived Wh Energy

VARh - Q1 & Q2 VARh in Quadrant 1VARh in Quadrant 2

VARh - Q3 & Q4 VARh in Quadrant 3VARh in Quadrant 4

VAh - Q1 & Q4 VAh in Quadrant 1VAh in Quadrant 4

VAh - Q2 & Q3 VAh in Quadrant 2VAh in Quadrant 3

Watt DemandDel & Rec

Watt Block DemandDelivered

Test Mode Displayed Data and Pulse Source

Test Mode Displayed Data Pulse Source

kWh, Del

kVARhr, Del

kVARhr, Rec

kVAhr, Q1

kVAhr, Q3

kWh, Del


While in Test Mode, the Test Pulse LED will pulse at the rate programmed for the meter Kt. Thevalue of the meter Kt can be verified from the meter’s Device Profile. The meter quantity assignedto the Test Pulse LED changes as the user moves from one test screen to another. The assigned values are defined in the Pulse Source column of the table above.

Changing the Kt value does not effect the meter’s performance or accuracy. The Kt value onlyeffects the rate at which the Test Pulse LED blinks. Smaller Kt values produce more pulses for agiven load and shorter test time. The tester should ensure that the allowed test time is long enoughto reduce variability that may be introduced in the starting and stopping of the test procedure.

Individual quadrant tests for VAR-hours can be completed by proper test design. To test strictlyVAR-hours, limit the test parameters to one quadrant during testing.

In the event of a power outage, data for Test Mode Energy, Demand and Power Factor are not saved.Upon power up, the meter returns to Normal Mode. The test data is lost and all registers arerestored to their pretest values.

While in Test Mode, the IR Port and Communications Port 1 are available for communicationwith the meter.

In Test Mode, the user can preset the values of the energy readings that will be restored to themeter when Test Mode is exited. This is accomplished with the Communicator EXT software (see section 4.2.4 (Test Mode Preset Accumulators) below or the programming sections of theCommunicator EXT User’s Manual).

4.2.3: Test Mode Exit Delay Setting

Set Exit Delay Time

1. From the Device Profile screen (section 4.2), click on the “Test Mode” icon or double-click on the“Test Mode Settings” line. The Test Mode Settings screen appears:

NOTE: The “Test Mode” icon and screen appear only if your Display Firmware is LESS THAN 40.If your Display Firmware is greater than 40, this setting will appear in the Programmable Settings.

2. Use the pull down menu to select the delay time in minutes (from 1 to 255 minutes). This is the time inwhich Communicator EXT will exit Test Mode if there is no activity. Click OK to return to the main Device Profile screen. For these changes to take effect, you must click on the Update Device button. This sends the new profile to the Nexus 1262/1272.Meters.


4.2.4: Test Mode Preset Accumulators

There are two reasons why a user might want to use the Preset Accumulators screens:

1. A monitor in Test Mode is out of service and is therefore not monitoring accumulations. The NewValue can be used to adjust for the values not monitored while in Test Mode.

2. When replacing an old meter that has accumulations with a new meter that has no accumulations,the New Value can be set with the value of the accumulations of the old meter.

Setting Test Mode Preset Accumulators

From the menu bar select Tools > Test Mode > Preset Accumulators. The set of screens shown here (Test Mode Preset Screens) appears.

Each screen has a Current Value, New Value and Preset Box for each accumulator. A new meter will have zeros for Current Values.

Click Tabs at the top of the screens to access the individual screens.

Settings can be preset for the following sets of values: Primary Energy, Secondary Energy, Primary Energy (Quadrants), Secondary Energy(Quadrants), Internal Input Accumulators, KYZ Output Accumulators, I & V Squared TAccumulators. Examples of some screens are shown here. Click the Preset Boxes for the values you want to set. Click Set or Cancel.

NOTE: Programmed (Accumulations) Rollover is set in the Device Profile (see section 3.22). If you try to enter a New Value greater than the Rollover value, the software will not let you.


4.2.5: Exiting Test Mode

Test Mode is exited in one of three ways:

1. By pressing and holding the Test Button for more than 3 seconds.2. By the Test Mode Time-Out Timer, if no load is present.3. By the Extended Test Mode Time-Out Timer, if load is present.

Pressing the Test Mode Button for more than three seconds will immediately exit Test Mode.

The Test Mode Time-Out Timer has two modes of operation, depending on whether the meter seesmeasurable load.

If the meter does not recognize measureable load:

The meter watches for user interaction by monitoring activity on the Test Button and the ResetButton. If neither button is pushed within the programmed Exit Delay time, the meter will automatically exit Test Mode and return to Normal Mode. Each time the Test or Reset Button ispressed, the meter starts the Exit Delay Timer again. The Exit Delay time is programmed in themeter’s Device Profile.

If the Meter recognizes measurable load:

It watches the Test and Reset Buttons for activity but uses a different time limit. When load is present, it uses an extended time consisting of the Exit Delay time plus the programmed BlockInterval Time. This insures that the meter can complete a full block demand test without interruption.

All Test Mode data is lost when Test Mode is exited. Upon exiting Test Mode, a new (possiblypartial) demand interval and subinterval are started. The past subinterval as well as the currentsubinterval are zeroed. Upon returning to Normal operating mode, a TOU meter or demand meterwith load profiling will complete the time remaining in the current partial subinterval such that subsequent subintervals will be synchronized with the hourly boundary.

Maximum demand values for each demand integration type are not modified while in Test Mode.The previously recorded maximums will be restored when Test Mode is exited. If the user desires toreset demand data during testing operations, this action can be completed after Test Mode is exited by pressing the Reset Button after the meter has reset to Normal Mode.

NOTE: Normal billing and historical log data accumulation is suspended during Test Mode operation. Upon exiting Test Mode, accumulation of billing and historical log quantities will:

1. Resume from the values in place when Test Mode was entered, or2. Continue from the values Preset while in Test Mode.

Figure 5.1: Communication Overview


Chapter 5Serial Communication Wiring

5.1: Communication Overview

RS-232 communication is used to connect a single Nexus 1262/1272 with another device, such as acomputer, RTU or PLC. The link is viable for up to 50 feet (15.2 m) and is available only throughthe Monitor’s Optical Port with a magnetic coupler (Optical Port to RS-232 Converter) (Fig. 5.2).

RS-485 communication allows multiple meters to communicate with another device at a local orremote site. The I/O modules and external displays use RS-485 to communicate with the meter. AllRS-485 links are viable for up to 4000 feet (1220 m). The Nexus Socket Meter’s Port 1 and 4 aretwo-wire, RS-485 connections (up to 115,200 baud). Optional Communication Connections forINP2 (Internal Modem with Dial In/Dial Out), INP100 (10/100BaseT connection).or INP102(Combination Modem and Ethernet) are cables with appropriate connectors (Fig. 6.2).

RS-232

RS-232

RS-485/232Converter

(Unicom 2500)

Optical Port to RS-232Converter (Smart Coupler)

Telephone Line,Fiber Optic Link or

Radio LinkRS-485/232 Converter(Modem Manager)

RS-485MODEMRS-232

OpticalPort

RS-485

Meter

Meter

Meter

4000 Feet 50 Feet

50 Feet

50 Feet4000 Feet

EElleeccttrroo IInndduussttrriieess//GGaauuggee TTeecchh Doc # E151-7-01 V1.01 5-2

Figure 5.2: Nexus 1272 Optical Port

Optical Port

5.2: Communicating to the Nexus through the ANSI C12.1 Optical Port

Use the ANSI C12.1 Optical Port on the face of the Nexus 1262/1272 Socket Meter for RS-232communication. The Optical Port is compatible with all standard ANSI C12.13 Type II magneticoptical communications couplers, SC-1A Smart Coupler, for example. See Figure 5.3.

One end of the magnetic coupler simply snaps onto the optical port; the magnet keeps it in place.The other end is an RS-232 connection. Insert that end into a port on a computer or other device.

The RS-232 standard limits the cable length to 50 feet (15.2m).


Figure 5.3: SC-1A Smart Coupler

5.3: RS-4485 Serial Communication

5.3.1: RS-4485 Wiring Fundamentals - (Port 1 and Port 4)

S Shield: It is not an earth-ground connection. You must also connect the shield toearth-ground at one point. Do not connect the shield to ground at multiple points; itwill interfere with communication.

A(+)/B(-)) Two-wwire, RS-4485 communication terminals: Connect the A(+) terminal of the MeterPort to the (+) terminal of the device. Connect the B(-) terminal of the Meter Port tothe (-) terminal of the device.

RS-232Connection

MagneticCoupler


For All RS-485 Connections:

Use Belden 3074F and 9841 cable types or twisted pair cable 22 AWG (0.33 mm2 ) or larger, grounding the shield at one end only.

Establish point-to-point configurations for each device on a RS-485 bus: Connect (+) terminals to(+) terminals; connect (-) terminals to (-) terminals.

Protect cables from sources of electrical noise.

Avoid both “star” and “tee” connections (see Figure 5.6). No more than two cables should be connected at any one point on an RS-485 network, whether the connections are for devices, converters or terminal strips.

Include all segments when calculating the total cable length of a network. If you are not using anRS-485 repeater, the maximum length for cable connecting all devices is 4000 feet (1219 meters).

Connect devices using the diagrams on the following pages. A correct connection requires 1/4 wattresistors connected to the (+) and (-) terminals of each device at the end of a straight-line bus. Theline impedance of the cable and the resistor should match. Generally, a 100- or 120-Ohm resistorwill work.

RS-485 communication allows multiple devices to communicate on a bus. The Meter’s Port 1 andPort 4 are RS-485 terminals, viable for a distance of up to 4000 feet (1219 m). Below is a detail ofa 2-wire RS-485 port.

Figure 5.4: 1262/1272 2-Wire RS-485 Port Detail


Correct Connection

Figure 5.5: 2-Wire RS-485 Connection

2-Wire RS-485 Connection

**NOTE 1: The Nexus 1262/1272 Meter may be shipped with connectors on the ends of cables or they may be shipped as pigtails (no connectors). In this case, a generic terminal block will be shipped with the meter. The terminal block has up to 12 connectors and can be cut into smaller sections with a utility knife. Please refer to the Cable Color Key on page 6-4, if you are using pigtails or if you have any question about which connector is which.

*NOTE 2: Termination Resistors are only needed with runs typically more than 500 feet. The meter has some level of termination internally and usually resistors are not needed.

**Cables may not haveconnectors. Pleasesee NOTE 1 below.

(For runs typically longer than 500 feet) See NOTE 2 below.

(For runs typically longerthan 500 feet)

*

*


Incorrect Connection: “T”

Figure 5.6: Incorrect “T” and “Star” Topologies

Incorrect Connection: “Star”

“Star” Connection Incorrect!

The three wires connected ina “Star” shape on both the(+) and (-) terminals willcause interference problems.

RS-485 Ports

RS-485 Port

“Tee” Connection Incorrect!

The three wires connected ina “T” shape on both the (+)and (-) terminals will causeinterference problems.


5.3.2: RS-4485 Connection—Monitor to a Computer or PLC

Use Port 1 or Port 4. For information on connecting the Monitor to a modem, see section 5.3.13 ofthis manual.

The link using RS-485 is viable for up to 4000 feet (1219 meters). You may need to use an RS-485to RS-232 converter.

5.3.3: RJ-111 (Telephone Line) Connection—Meter with INP2 (Internal Modem with Dial In/Dial Out Option) to a PC

Use RJ-11 Standard Telephone Line to connect with the Meter. The RJ-11 line is connected to Cable5 from the back of the Meter with Internal Modem Option. The RJ-11 connector is supplied.

The length of the connection using RJ-11 into the Meter is virtually unlimited. To connect withother Monitors in either local or remote locations, you MUST use Cable 5.

For more information on the Monitor with the INP2 Option, see section 5.4 of this manual.

5.3.4: RJ-445 Connection—Meter with INP100 (10/100BaseT) Option

The INP100 Option conforms to the IEEE 802.3, 10/100BaseT specification using unshielded twisted pair (UTP) wiring. This allows the use of inexpensive RJ-45 connectors and CAT 3 or bettercabling. The RJ-45 connector is supplied with the meter (Cable 6).

Using this LAN connection allows multiple PC’s to access the meter concurrently. The RJ-45 line isinserted into the RJ-45 connector on Cable 6 coming from the back of the Nexus with EthernetOption. The connection using RJ-45 into the Meter connects the Meter to a network usingModbus/TCP protocol over Ethernet.

For more information on the Meter with the INP100 (10/100BaseT), see section 5.5 of this manual.

5.3.5: Modem/Ethernet Connection—Meter with INP102 (Combo Card) Option

The INP102 is an extension of INP100. It has all the features of INP100 plus a built-in Modem.Modem and Ethernet capabilities can be used simultaneously.

The communication protocol supported by the modem is Modbus ASCII. The Communication protocol supported by the RS-485 Ethernet/Modem Gateway is Modbus RTU. INP102 converts allincoming modem Modbus ASCII requests to Modbus RTU for internal and gateway communication.It then converts all response Modbus RTU messages into Modbus ASCII protocol before it sends theresponses to the modem.

Some of the fixed parameters for the Ethernet/Modem Gateway are: 8 Data Bits, Even Parity, 1 StopBit. Ethernet/Modem Gateway’s Baud Rate and Delay Time are configurable.


5.3.6: RS-4485 Connection—Meter to an RS-4485 Master

To establish communication between a Monitor and any RS-485 master, use a shielded, twisted paircable.

Use an RS-485 port (Port 1 or Port 4) on the Monitor. Connect the A(+) and B(-) terminals on theMeter to the (+) and (-) terminals on the master. Provide jumpers only on a 4-wire master, linkingits two (-) terminals and two (+) terminals. RS-485 communication is viable for up to 4000 feet(1219 meters).

Connect the shield to the Ground (G) terminal on the Master. You must also connect the shield toearth-ground at one point.

Provide resistors at each end, connected to the (+) and (-) lines. RT is ∼120 Ohms.

NOTE: Termination Resistors are only needed with runs typically more than 500 feet. The meter hassome level of termination internally and usually resistors are not needed.

Figure 5.7: Monitor Connected to an RS-485 Master

Port on RS-485Master

RS-485 Port on1262/1272 Monitor **Cables may not have

connectors. Please refer to Cable Color Key, page 6-4 and NOTE 1, page 5-5.

* (For runs typically longer than 500 feet)


P40N LED Display, Back View


5.3.7: RS-4485 Connection—Monitor to the P40N LED External Display

Insert the communication wires of the supplied RS-485 cable into the Port 4 connection of theMonitor. Port 4 is factory-set to match the LED Display’s baud rate of 115200. To use a port otherthan Port 4, you must set the port’s baud rate to 115200 using the communication software (see the accompanying User Manual). Insert the other end of the communication wires into the back of theP40N LED Display.

Nexus 1262/1272 Power Supply DOES NOT SUPPLY POWER TO EXTERNAL DISPLAYS. Youmust use a power source, such as the EIG PSIO. See Figure 5.8 for wiring details. RS-485 communication is viable for up to 4000 feet (1219 meters). Be sure to do the following:

• Connect the shield to the shield (S) terminal on the Display port. The (S) terminal on the Nexusis used to reference the Nexus port to the same potential as the source. It is not an earth-ground connection. You must also connect the shield to earth-ground at one point.

• Provide termination resistors at each end, connected to the A(+) and B(-) lines. RT is approximately 120 Ohms.

Figure 5.8: Monitor Connected to P40N LED External Display

LED Display Port

1262/1272 Port 4

RT

RT *

V+

V-S

B(-)

A(+)

Top

Bottom

**Cables may not have connectors. Please refer to Cable Color Key, page 6-4 and NOTE 1, page 5-5.



P60N Touch Screen Display, Back View (Detail)

Top

Bottom

5.3.8: RS-4485 Connection—Monitor to P60N Touch Screen External Display

To connect the Touch Screen External Display, follow the wiring directions for the P40N in section 5.3.7 and follow the wiring diagram in Figure 5.8. The only difference between the two displays is that the port on the P60N is in the lower right hand corner of the back of the display (not in the center of the back) as shown below.

Touch ScreenDisplay Port

Figure 5.9: P60N Touch Screen Display Port

P60N Touch Screen Connection Key

LCD Meter

5 DCIN (12-30Vdc)

4 (GND)

V+

V-

3 (485+) A(+)

2 (485-) B(-)

1 (GND) S

Factory TestConnector


5.3.9: Communication Ports on the I/O Modules

Female RS-485 Side Port: use to connect to another module’s male RS-485 side port.

Male RS-485 Side Port: use to connect to the Monitor’s Port 4 (see section 5.3.6) or to connect toanother module’s female RS-485 side port.

I/O Port: use for functions specific to the type of module; size and pin configuration varies depending on type of module. For more detail, refer below to section 5.3.10 and to Chapter 10 ofthis manual.

Figure 5.10: Communication Ports on the I/O Modules

I/O Port(Size and pin

configuration vary)

Female RS-485 Side Port

Male RS-485 Side Port

Mounting Brackets

LEDs


5.3.10: RS-4485 Connection—Monitor to I/O Modules

RS-485 cable harness is supplied with the purchase of MBIO (mounting brackets). Insert one end ofthe cable into Port 4 of the Monitor.

Insert the other end of the cable into the communication pins of the I/O module’s male RS-485 sideport (see Figure 5.9). See section 10.3 for details on using multiple I/O modules.

Nexus 1262/1272 Power Supply WILL NOT SUPPLY POWER TO THE I/O MODULES. You mustuse a power source, such as the EIG PSIO (12V). RS-485 communication is viable for up to 4000feet (1219 meters). (See section 10.2.1 for PSIO details.)

Follow the wiring diagram below and be sure to:

• Connect the A(+) and B(-) terminals on the Meter to the A(+) and B(-) terminals of the femaleRS-485 port. Connect the shield to the shield (S) terminal. The (S) terminal on the Meter is usedto reference the Meter port to the same potential as the source. It is not an earth ground connection. You must also connect the shield to earth-ground at one point.

• Provide termination resistors at each end (see note below), connected to the A(+) and B(-) lines. RT is approximately 120 Ohms.

NOTE: Termination Resistors are only needed with runs typically more than 500 feet. Themeter has some level of termination internally and usually resistors are not needed.

Figure 5.11: Monitor Connected to I/O Module

RT *

RT

Male Side Port onI/O Module

1262/1272 Port 4

* (For runs typically longer than 500 feet) See NOTE above.

* (For runs typically longer than 500 feet) See NOTE above.


5.3.11: Steps to Determine Power Needed

• Nexus 1262/1272 Power Supply DOES NOT SUPPLY POWER to the I/O Modules.

• Refer to the table in the next section (Section 5.3.11) to determine the VA Ratings for I/Omodules and displays.

• Add together the VA Ratings for I/Os and Displays in use.• Determine Power Needed.• Each PSIO will supply 12 VA @ 12Vdc. For details on PSIO, see section 10.2.1.

5.3.12: I/O Modules’ Factory Settings and VA Ratings

All I/Os are shipped pre-programmed with a baud rate of 57600 and individual addresses. The tablebelow details the factory-set address for each module and the VA Ratings for I/O modules and displays. Refer to the previous section (section 5.3.11) for the steps to determine the powerrequired. For programming details, refer to the accompanying Communicator EXT User Manual.

I/O MODULES’ FACTORY SETTINGS AND VA RATINGS

MODEL NUMBER

1mAON4

1mAON8

20mAON4

20mAON8

8AI1

8AI2

8AI3

8AI4

4RO1

4PO1

8DI1

MODULE

0-1mA, 4 Analog Outputs




±0-1mA, 8 Analog Outputs

±0-20mA, 8 Analog Outputs

±0-5Vdc, 8 Analog Outputs

±0-10Vdc, 8 Analog Outputs

4 Latching Relay Outputs

4 KYZ Pulse Outputs

8 Status Inputs (Wet/Dry)

DISPLAYS’ VA RATINGS

ADDRESS VA RATING

128 2.7 VA

128 3.2 VA

132 5.0 VA

132 8.5 VA

136 2.3 VA

140 2.3 VA

144 2.3 VA

148 2.3 VA

156 2.7 VA

160 2.7 VA

164 1.0 VA

P40N

P60N

LED Display

Touch Screen Display

8 VA

5 VA


Figure 5.13: Linking Isolated Units in Series

RS-485 PortRS-485 PortNexus RS-485 Master

Up to 31 1262/1272 Monitors Maximum

5.3.13: Linking Multiple Devices in Series

You may connect a total of 31 Monitors in series on a single bus using RS-485. The cable lengthmay not exceed 4000 feet (1219 meters). Before assembling the bus, each Monitor must be assigneda unique address; see the accompanying Communicator EXT User Manual.

Connect the A(+) and B(-) terminals of each device.

Break shield between RS-485 Master and between device segments per Figure 5.12. It is not anearth ground connection. You must also connect the shield to earth-ground at one point.

Provide resistors at each end, connected to the (+) and (-) lines. RT is ~120 Ohms.

Figure 5.12: Linking Multiple Devices in Series

NOTE: Alternative wiring for ISOLATED UNITS is shown below.

* For runs typically longer than 500 feet. See NOTE 2, page 5-5.

*

*

*

* See above


Telephone Line Remote Modem

NULL Modem Adapter(Not required if Modem Manager is used)

RS-485

OriginateModem

RS-232 to RS-485Converter

(Modem ManagerRecommended)

Nexus 1262/1272Monitor

PC at office

Figure 5.14: Remote Connections—RS-485

5.3.14: Remote Communication Over Telephone Lines Using the RS-4485 Port

Use modems (dedicated or dial-up) when devices are at great distances. We recommend using RS-485 wiring with a Modem Manager.

Remote Connection—RS-485


Use Port 1 or Port 4 for RS-485 communication. The link using RS-485 is viable for up to 4000 feet(1219 meters).

Use Communicator EXT software to set the port’s baud rate to the appropriate speed for your hardware and/or network and enable Modbus ASCII protocol. See the Communicator EXT Manual.

You must use an RS-485 to RS-232 converter and a Null Modem. EIG recommends using itsModem Manager. This converter has a built-in null modem and also provides line data buffering,making the telephone line communication reliable; most commercial modems do not. For this reason, EIG recommends the Modem Manager to alleviate any communication line errors that mightoccur.

Using the Modem Manager also eliminates the need to program default settings into the modem.This makes installation simpler.


5.3.15: Programming Modems for Remote Communication

When a modem speaks to most RS-485 or RS-232-based devices, it must be programmed to certain settings for the communication to work. This task is often quite complicated. Modem Manager wasdesigned to eliminate this step.

If you are not using a Modem Manager device, you must follow the steps below to communicate withthe remote Monitor(s). Consult your modem’s manual for the proper string settings or see section 5.3.16for a list of selected modem strings.

Modem Connected to a Computer (the Originate Modem):

• Restore modem to factory settings. This erases all previously programmed settings.

• Set modem to display Result Codes. The computer will use the result codes.

• Set modem to Verbal Result Codes. The computer will use the verbal result codes.

• Set modem to use DTR Signal. This is necessary for the computer to ensure connection with theoriginate modem.

• Set modem to enable Flow Control. This is necessary to communicate with remote modem connected to the Meter.

• Tell modem to write the new settings to activate profile. This places these settings into nonvolatile memory; the setting will take effect after the modem powers up.

Modem Connected to the Monitor (the Remote Modem):

• Restore modem to factory settings. This erases all previously programmed settings.

• Set modem to auto answer on N rings. This sets the remote modem to answer the call after Nrings.

• Set modem to ignore DTR Signal. This is necessary for the Meter to ensure connection withoriginate modem.

• Set modem to disable Flow Control. RS-232 communication does not support this feature.

• Tell modem to write the new settings to activate profile. This places these settings into nonvolatile memory; the setting will take effect after the modem powers up.

• When programming the remote modem with a terminal program, make sure the baud rate of theterminal program matches the Monitor’s baud rate.


5.3.16: Selected Modem Strings

Modem String/SettingCardinal modem: AT&FE0F8&K0N0S37=9Zoom/Faxmodem VFX V.32BIS(14.4K): AT&F0&K0S0=1&W0&Y0Zoom/Faxmodem 56Kx Dual Mode: AT&F0&K0&C0S0=1&W0&Y0USRobotics Sportster 33.6 Faxmodem: AT&F0&N6&W0Y0 (for 9600 baud)

DIP switch setting: Up Up Down Down Up Up Up DownUSRobotics Sportster 56K Faxmodem: AT&F0&W0Y0

DIP switch setting: Up Up Down Down Up Up Up Down

C1

+

235678

Optional 150Vdc Max for wet contacts

5.3.17: High Speed Inputs Connection

The High Speed Inputs can be used in multiple ways (1272 Only):

1. Attach the KYZ pulse outputs from other meters for pulse counting and totalizing.2. Attach status contacts from relays, breakers or other devices for status or waveform initiation.

Refer to the accompanying User Manual for information on programming the functionality ofthese versatile inputs.

The High Speed Inputs can be used with either dry or wet field contacts. For WET contacts, the common rides on a unit-generated 15Vdc. No user programming is necessary to use either wet or dry field contacts.

Figure 5.15: High Speed Inputs Connection

4


++

-

IRIG-B Port

5.3.18: IRIG-BB Connections

IRIG-B is a standard time code format that synchronizes event timestamping to within 1 millisecond.An IRIG-B signal-generating device connected to the GPS satellite system will synchronize Nexus1270 and 1272 Monitors located at different geographic locations. Nexus 1272 utilizes anUNMODULATED signal from a satellite-controlled clock (such as the Arbiter 1093B). For detailson installation, refer to the User’s Manual for the satellite-controlled clock in use. Below areinstallation steps and tips that will help you. (Nexus 1262 Monitors do not use IRIG-B.)

-

IRIG-B TimeSignal

GeneratingDevice

GPS Satellite Connection

Figure 5.16: IRIG-B Connection

Installation:1. Set Time Settings for the monitor being installed. From Communicator EXT, Device

Profile, Click Time Settings. Set the Time Zone and Daylight Savings Time. Click Update Device Profile to save the new settings. (See Communicator EXT User’s Manual.)

2. Before connection, check that the date on the satellite clock is correct (or, within 2 MONTHSof the actual date). This provides the right year for the clock (GPS does not supply the year).

3. Connect the (+) terminal of the Monitor to the (+) terminal of the signal generating device; connect the (-) terminal of the Monitor to the (-) terminal of the signal generating device.

Troubleshooting Tip: The most common source of problems is a reversal of the two wires. Tryreversing the wires.


5.3.19: Time Synchronization Alternatives (See Communicator EXT User’s Manual fordetails.)

IRIG-B:All Nexus Monitors, except 1262, are equipped to use IRIG-B for Time Sychronization. If IRIG-B is connected, this form of Time Synchronization takes precedence over the InternalClock. If the GPS Signal is lost, the Internal Clock takes over time keeping at the precise moment the signal is lost..

Line Synchronization:All Nexus Monitors are equipped with Line Synchronization, which may be Enabled or Disabled for use instead of IRIG-B. If Line Synchronization is Enabled and power is lost, the Internal Clock takes over at the precise moment power is lost.

Internal Clock:All Nexus Monitors are equipped with Internal Clocks, which can be used if IRIG-B is not connected and/or Line Sync is not Enabled. If either of the above Time Sync Tools fails, the Internal Clock will take over at the precise moment the synchronization tool in use fails.

Time Setting Tools:

1. Tools, Set Nexus Time: For manual or PC Time Setting.

2. Script & Scheduler: Time Stamps Retrieved Logs and Data.

3. MV90: Can synchronize time on retrievals in the form of a Time Stamp.


5.4: INP2 Internal Modem with Dial-IIn In/Dial-OOut Option

5.4.1: Hardware Overview

The INP2 Option for the Nexus 1262/1272 meter provides a direct connection to a standard telephone line. No additional hardware is required to establish a communication connection betweenthe meter and a remote computer.

The modem operates at up to 56k baud. The internal connection between the modem and the meterincludes a memory buffer. This enables the modem to connect to the phone line at any speed and tochange speed during the communication connection to the remote PC. The buffer between the meterand the modem allows the meter to communicate into the modem at a constant speed while themodem telephone line speed can vary. This eliminates the synchronizing problems that are commonwith other devices. It also increases the effective throughput of the communication channel. This, inturn, decreases connection time and connection costs.

The modem supports both incoming calls (from a remote computer) and automatic dial-out callswhen a defined event must be automatically reported.

5.4.2: Hardware Connection

When the INP2 Option is ordered, there are two RJ-11 jacks that pigtail from the back of the meter (1. Line connection for the outside line 2. Phone connection for your phone). A standard telephone RJ-11 plug can connect the meter to a standard PSTN (Public Switched Telephone Network). The phone jack is the override of the modem function when the phone is in use.

With the device configured with the INP2 Option, the meter has dial-in capability and providesremote access to other Modbus-based serial devices via the meter’s RS-485 Gateway over your phone line. The meter will recognize and respond to a Modbus Address of 1. With any other address, the command will pass through the gateway and become a virtual connection between the Remote Modbus Master and any Modbus Slave connected to the RS-485 Gateway.

5.4.3: Dial-IIn Function

The modem continuously monitors the telephone line to detect an incoming call. When an incomingcall is detected, the modem will wait a user-set number of rings and answer the call.

The modem can be programmed to check for a password on an incoming call. If the correct password is not provided the modem will hang up on the incoming call. If several unsuccessfulincoming call attempts are received in a set time period, the modem will lock out future incomingcalls for a user-set number of hours.

When an incoming call is successfully connected, the control of communications is passed to thecalling software program. The modem will respond to computer commands to download data orother actions authorized by the meter passwords.

Refer to the Communicator EXT Software Manual for instructions on programming the modem.


5.4.4: Dial-OOut Function

The Dial-Out Function (INP2) is intended to allow the meter to automatically report certain conditions without user intervention. The modem is normally polling the meter to determine if anyabnormal or reportable conditions exist. The modem checks the following meter conditions and programmed events (set in Communicator EXT) to determine if a call should be placed.

• Are any meter set-point limits exceeded?• Has status of high-speed inputs changed?• Has waveform been recorded?• Has power quality event been recorded?• Has a control output changed?• Has meter experienced a loss of control power?• Is either history log approaching a full condition?• Is the event log approaching a full condition?• Is any other log approaching a full condition?• Has the Modem Password failed?• Has Communication with the Nexus failed?

If any of the monitored events exist, the modem will automatically initiate a call to a specified location to make a report or perform some other function. For log full conditions, the meter willautomatically download the log(s) that are nearing the full state. The modem can be programmed tocall two different numbers to make the required reports, Primary and Backup.

The modem can be programmed with an ASCII string for identification purposes. If this string inpresent the modem will play the string to the host computer upon connection to identify the meter tothe host software. Refer to the Communicator EXT Software Manual for programming details.

The modem includes a connection for an external 3V Lithium Battery (with custom leads and velcromounting) to power the modem if the meter loses control power. Using the battery, the modem willbe able to complete a reporting call even if power to the meter has been disconnected. This featureallows the meter to report power outage conditions. Under normal conditions, the battery shouldprovide in excess of 10 years of service during storage conditions (disconnected from terminals) orwhen properly installed in an energized meter. The battery should provide more than one year ofservice during outage conditions (on battery backup). A LOW BATTERY indicator will appear onthe display screen (ONLY when there is a low battery). Call the factory for a replacement battery.

Replacement of the battery is simple. The battery is attached to a cable (if ordered) which pigtails from the back of the meter with a connector (see NOTE below and Fig. 6.2 and Table 6.1). Installation steps:

1. Remove the old battery by disconnecting it at the connector.2. Install the new battery by snapping it into the connector.3. Peel and stick the velcro adhesive somewhere outside the meter (or use the old adhesive to fasten

the battery in place).

NOTE: Custom leads and Velcro mounting are not included in some earlier versions of the SwitchboardMeter. Call the factory for installation/replacement part BATT4384.


5.5: Total Web Solutions

The 10/100BaseT Ethernet Option (INP100) is a fully customizable web server that uses XML to provide access to real-time data via Internet Explorer. EIG’s name for this dynamic system is TotalWeb Solutions. The system incorporates a highly programmable network card with built-in memorythat is installed in the 100BaseT Option meters. Each card can be programmed to perform an extensivearray of monitoring functions and the system is much faster than the 10BaseT Ethernet Option.

NOTE: Nexus meters with the INP10 Option do not support Total Web Solutions.


The Nexus 1262/1272 with the 10/100BaseT Ethernet Option (INP100) has all the components ofthe standard Nexus PLUS the capability of connection to a network through an Ethernet LAN orthrough the Internet via Modbus TCP, HTTP, SMTP, FTP and/or DHCP.

The Internal Network Option of the Nexus Monitor is an extremely versatile communication tool.· Adheres to IEEE 802.3 Ethernet standard using TCP/IP.

· Utilizes simple and inexpensive 100BaseT wiring and connections.

· Plugs right into your network using built-in RJ-45 jack.

· Programmable to any IP address, subnet mask and gateway requirements.

· Communicates using the industry standard Modbus/TCP protocol.


Use Standard RJ-45 10/100BaseT cable to connect with the Nexus. The RJ-45 line is inserted into the RJ-45 Port coming from the back of the Nexus with INP100 Ethernet Option.

To make the software connection, use the following steps.

1. Using Port 1 or Port 4 (RS-485 connection), connect a PC to the meter. An RS-232/RS-485 Converter may be required (Example: Electro Industries Unicom 2500).

2. Double click on Communicator EXT Software to open.

3. Click the Quick Connect or the Connection Manager icon in the icon tool bar. Click the Serial Port button. Make sure data matches the meter then click Connect.

Set the Network Settings using the following steps: (Refer to Section 3.6 of the Communicator EXT User Manual for more details).

1. From the Device Profile screen, double-click on the Communications Ports line, then double-click on any of the ports. The Device Profile Communications Settings screen appears.


2. If you are going to use DHCP, click the Advanced Settings Button:

Click the tab at the top of the DHCP screen. Click Enable. DHCP will automatically enter the IP Address and some or all of the Interface Settings. Click OK at the bottom of the screen to return to the Device Profile: Communication Ports screen. You may have to manually enter DNS, Email, Gateway Setting and/or a Unique Computer Name. Click OK.

3. If you are NOT using DHCP, in the Network Settings section, enter data provided by your systems manager:

IP Address: 10.0.01 (Example)Subnet Mask: 255.255.255.0 (Example)Default Gateway: 0.0.0.0 (Example)Computer Name: NETWORK (Example)

Enter the Domain Name Server and Computer Name.

Customize Web Content, if desired. Default Pages with an extensive array of readings comes withthe meter. The content of the pages can be customized using FTP Client.

From the Device Profile: Communications Ports screen, click Advanced Settings. Click the FTPClient tab on the top of the folder. Using FTP, you can easily replace any file by using the SAME FILE NAME as the one you want to replace.

Enter the Email Server IP Address. The Default Settings store ONE Email Server IP Address foradministrative purposes or to send an alarm, if there is a problem. An ADDITIONAL 8 can be configured with FTP Client.

Update FIRMWARE, if needed, with TFTP protocol (see Appendix C).

After the above parameters are set, Communicator EXT will connect via the network using a DeviceAddress of “1” and the assigned IP Address using the following steps:

1. Double click on Communicator EXT icon to open.

2. Click the Connect icon in the icon tool bar. The Connect screen will appear.3. Click the Network button at the top of the screen. The screen will change to one requesting the

following information:

Device Address: 1Host: IP Address (per your network administrator).

Example: 10.0.0.1Network Port: 502Protocol: Modbus TCP

4. Click the Connect button at the bottom of the screen. Communicator EXT connects to the Nexus with the Host IP Address via the Network.


5.6: INP102 Ethernet/Modem Combination

The INP102 Option is an extension of INP100. It has all the features of INP100 plus a built-in modem. The communication protocol supported by the modem is Modbus ASCII. The communication protocol supported by the RS-485 Ethernet/Modem Gateway is Modbus RTU. INP102 converts all incoming Modem Modbus ASCII requests to Modbus RTU for internal and gateway communication. It then converts all response Modbus RTU messages into Modbus ASCII and sends the responses to the modem.


The Nexus 1262/1272 with INP102 Option has all the components of INP100 Nexus PLUS a built-in modem. It has the capability of connection to a network through an Ethernet LAN or through theInternet via Modbus TCP, HTTP, SMTP, FTP and/or DHCP. It can also simultaneously connect with other devices via modem.


There are three cables to connect for the INP102 Option. An RS-485 Gateway cable, an RJ-45 Ethernet cable and an RJ-11 Modem cable are inserted into the cables coming from the back of the Nexus with INP102 Ethernet/Modem Option. Refer to Fig. 6.2 for details on cables.

To make the software connection, use the following steps.

1. Using Port 1 or Port 4 (RS-485 connection), connect a PC to the meter. An RS-232/RS-485 Converter may be required (Example: Electro Industries Unicom 2500).

2. Double click on Communicator EXT Software to open.

3. Click the Quick Connect or the Connection Manager icon in the icon tool bar. Click the Serial Port button. Make sure data matches the meter then click Connect.

Set the Network Settings using the following steps: (Refer to Section 3.6 of the Communicator EXT User Manual for more details).

1. From the Device Profile screen, double-click on the Communications Ports line, then double-click on any of the ports. The Device Profile Communications Settings screen appears.See section 5.5.2 for settings.

2. Once all parameters are set, click the Connect button at the bottom of the screen. Nexus Communicator connects to the Nexus with the Host IP Address via the Network.

3. Follow connection instructions for the modem in section 5.4.

Chapter 6Hardware Installation

6.1: Mounting the Nexus Socket Meter

The Nexus 1262/1272 Socket Meter is designed to mount into a standard meter socket. Follow theInstallation Summary below or follow the installation instructions on the meter socket to ensure thatthe unit is installed securely. The Nexus Socket Meter can be mounted outside or in an enclosedand protected environment, such as in a switchgear cabinet. You may install a switch or circuitbreaker nearby and label it clearly as the Monitor’s disconnecting mechanism.


Figure 6.1: Nexus 1262/1272 Mounting Dimensions

Installation Summary

• Examine the labels to verify that the meter you are installing is, in fact, the correct form factorand service type. Make sure that the socket and meter current class ratings are compatible.

• Make sure that all communication and auxiliary power wiring is accessible in case disconnection is required for any reason.

• Before applying power to the meter, install batteries if not installed at the factory and checkthe connections if they are installed. POWER MUST BE OFF TO INSTALL THEINTERNAL BATTERY! To install the Internal Battery, remove the Internal Shroud and placethe battery into the battery compartment with the + facing UP. Replace the Internal Shroud. Toinstall the Modem Battery, with the Outer Shroud on the meter, locate the battery cable at theback of the meter and insert the cable connector into the cable. Use the velcro (peel and stick)to attach the battery somewhere outside of the meter. See Figure 6.2.

I/OsSide ViewFront View

1.10”1.13”

1.32”

3.44”2.20”


• Measure the enclosure to make sure it accomodates the meter. (If it is standard size, that won’tbe necessary.)

• Make sure that any communications wiring from the back of the meter is fed through the appropriate openings in your socket to allow for clean connections with external devices.

• Insert the meter into the socket, making sure that the unit blades are firmly within the jaws ofthe socket.

• Connect external devices to the appropriate communications wiring. See Figure 6.2 and Table6.1, Cable Color Key, below for communications wiring details. RJ-11 and RJ-45 connectorswill be supplied. All Nexus socket meters are wired like the Nexus 1272 pictured below.

• Make sure the meter is functioning properly by running it through a test circuit.

• The Nexus Socket Meter has its own display built into the face of the meter. However, you maywant to install additional displays in remote locations. Following are the Installation Proceduresfor the Nexus P40N and P60N Displays. Installation Procedures for Nexus I/O Modules arealso provided in this chapter.

Figure 6.2: Nexus 1272 Rear View Diagram

Cable 2Cable to High Speed Inputs

Cable 3Optional KYZ Cable

Cable 1Port 1 Port 4 IRIG-B

OptionalAuxPowerCable OPTIONAL

COMMUNICATION

Combo Modem/EthernetCable 4RS-485 GatewayCable 5RJ-11 ModemCable 6RJ-45 Ethernet

Modem Cable 4RS-485 GatewayCable 5RJ-11 Modem Cable 7Battery

EthernetCable 6RJ-45 Ethernet


Figure 6.3: Nexus 1262/1272 Mounted in A-Base Bottom

Figure 6.4: Nexus 1262/1272 Mounted (Side View)

4.25” 107.95 mm)

7.00”(177.9mm)

10.17”(258.32mm)

0.88”(22.35mm)

2.00”(50.8mm)

6.25”(158.8mm)

6.1.1: Cable Color Key


CABLE

PORT 4 Wiring (RS-485)

Yellow

Green

COLOR

Blue

Black

Brown

Red

Orange

Yellow

Green

Blue

Gray

Purple

Black

Brown

Red

Orange

Yellow

Green

Blue

Purple

Gray

Light Green

Pink

White

IMPORTANT NOTE: Cable colors are subject to change without notice in this manual. Refer to CABLE LABELS for color code verification.

Table 6.1: Nexus 1262/1272 Cable Color Key

Cable 2

Cable 3

NORMALLY OPEN 3

NORMALLY CLOSED 4

COMMON

NORMALLY OPEN 4

COMMON

NORMALLY CLOSED 3

NORMALLY OPEN 2

COMMON

NORMALLY CLOSED 2

NORMALLY OPEN 1

COMMON

NORMALLY CLOSED 1

Optional KYZ Output

COMMON

INPUT 1

INPUT 2

INPUT 3

INPUT 4

INPUT 5

INPUT 6

INPUT 7

INPUT 8

HIGH SPEED INPUTS

Tx/Rx +

IRIG-B

Tx/Rx -

Tx/Rx +

SIGNAL NAMEPORT 1 Wiring (RS-485)

SHIELD

Tx/Rx +

COLORCABLE SIGNAL NAME

Cable 4

RS-485 Gateway

SHIELD

Tx/Rx+

Blue

Tx/Rx-

Green

Red

Cable 5

Cable 6

Cable 7

RJ-11 Modem

RJ-45 Ethernet

Battery

Blue

BlueLabel attached

Label attached

BlackLabel attached

Black

Tx/Rx -

Brown

Red

Cable 1

PurpleTx/Rx -

SHIELD Orange

+

Doc #: E151-7-01 V1.01 Electro Industries/GaugeTech

InternalBattery

Fig. 6.5: Nexus 1272 without Internal Shroud

6-5

CAUTION - BATTERY INSTALLATION OR REPLACEMENT MUST BE DONE WITH POWER OFF!

The Internal Battery is a 3V Lithium Battery (Panasonic BR2032 or equivalent) that maintains NVRAM and timeduring outages. It is located on one of the vertical panels inside the Internal Shroud (see Fig. 6.5 above). Undernormal conditions, the battery should provide in excess of 10 years of service during storage conditions (disconnectedfrom terminals) or when properly installed in an energized meter. The battery should provide more than one year ofservice during outage conditions (time on battery backup). A LOW BATTERY indicator on the display screen willtell you when replacement is needed. Installation steps:

1. If you are replacing a battery, download all memory files to your computer. Data may be lost.2. Remove power from the meter.3. Remove the external meter cover and the internal shroud.4. Remove the old battery with a screwdriver or similar tool.5. Place the new battery in the battery holder according to the directions in Section 6.2.1 below.

Make sure you place the + facing up.6. Replace the internal shroud and the external meter cover.7. Energize the meter.8. Reset Time using Communicator software. If IRIG-B is connected, time is synchronized automatically.

6.2: Internal Battery Installation and Maintenance

6.2.1: Battery Holder Detail

NOTE: It is very important to insert the replacement battery into the holdercorrectly. Otherwise proper contact will not be achieved and the meter maylose log memory and time functions.

Figure 6.6: Battery Holder Detail

• STEP A: Make sure the + on the battery is facing UP and toward you.Insert the RIGHT SIDE of the battery UNDER the 2 clips on the right side of the holder whilegently pushing the battery against the INSIDE RIGHT WALL of the battery holder (Arrow A).

• STEP B: Gently push the LEFT SIDE of the battery in until it snaps into place (Arrow B).

6.2.2: Battery Safety and Disposal

• Do not expose battery to temperatures above 100 degrees C. Do not incinerate, puncture, crush,recharge, short-circuit or over-discharge battery.

• Do not expose contents of battery to water or to high humidity for extended periods of time.

• Dispose of batteries in accordance with local, state and federal hazardous waste regulations.

NOTE: The replacement of the Modem Battery is detailed in section 5.4.4.



6.3: Mounting the Optional Nexus P40N LED External Display

The Nexus 1262/1272 has its own LCD Display on the face of the meter. The optional Nexus LEDDisplay, Model # P40N, may be used where additional displays are desired. The display mountsusing a standard ANSI C39.1 drill plan. Secure the four mounting studs to the back of the panelwith the supplied hardware.

Six feet of RS-485 communication/power cable harness is supplied. Allow for at least a 1.25-inch(3.17cm) diameter hole in the mounting panel for the cable harness. See Chapter 6 for more details.

The display is powered by an external power source, such as the PSIO, which supplies 12Vdc. TheP40N can draw up to 500 mA in display test mode. See Figure 6.6 and 6.11 for wiring detail (wiringis the same as the P60N and I/O Modules).

Figure 6.7: Nexus P40N LED External Display Mounting Diagrams

Nexus P40N Display, Front View Nexus P40N Display, Side View

+

3.38” (8.58cm) Sq.

1.687” (14.28cm)

4 X 0.198” (5.02mm)

4.00” (10.16cm)

4.38”Sq.(11.12cm)

1.438”(3.65cm)

.75” (19.05mm)

ANSI C39.1 Drill Plan


6.4: Mounting the Optional Nexus P60N Touch Screen External Display

The Nexus P60N Touch Screen Display mounts easily, using these diagrams. A bezel and a gasketare included with the P60N. Since the P60N employs an LCD display, the viewing angle must beconsidered when mounting. The P60N is powered by an external power source, such as the PSIO.See Figures 6.6 and 6.11 for wiring. NOTE: The P60N WILL NOT display TOU Data.

For optimum performance, maintain the following conditions where the Touch Screen Display is mounted:

• Operating Temperature: (0 to+50)°C / (+32 to +122)°F

• Storage Temperature: (-20 to +70)°C / (-36 to +158)°F

• Relative Humidity: (25 to 65)% non-condensing

NOTE: One of the display-mounting studs MUST be grounded (automatic ifmounted in a metal grounded panel).

Figure 6.8: Nexus P60N Touch Screen Display Mounting Diagram

Figure 6.9: Nexus P60N Back Detail

NEXUS to485+, 485- and GND

Factory Test Connector

Aux Power(PSIO) to pins 4, 5

Figure 6.10: Cutout for Nexus P60N Touch Screen Display


To mount the P60N, cut an opening in the mounting panel. Follow above cutout dimensions. Carefully “drop in” the P60N with bezel and gasket attached. See Figure 6.8 above for details.Fasten the unit securely with the eight nuts supplied.

6.5: Daisy Chain Meters with the P60N

Data from up to 8 meters can be accessed with one P60N Display using the steps below:1. Connect up to 8 meters to one P60N as shown in Figure 6.11 below.2. Using the P60N face, touch the SETTINGS Button > NEXT > LINK SETTINGS.3. Touch UP (on the LINK SETTINGS screen) to add an Address. Each slave device in the chain

MUST be assigned a UNIQUE ADDRESS. A SAVE Button will appear.4. Touch the SAVE Button to Save the New Address.5. Select the Address for the meter from which you want to access data.

Chapter 10 details the screens and the Navigational Map for the P60N Display.6. Click NEXT to select a screen from which you want to retrieve data.

Figure 6.11: Daisy Chain Meters with the P60N Touch Screen Display


6.6: Mounting the Nexus External I/O Modules

Connect multiple I/O modules by inserting male RS-485 side ports.into female ports, then using aflathead screwdriver, screw each module into the next. Work from left to right.

If multiple I/O modules are connected together, as shown in Figure 5.9, (or an individual module isused) secure the mounting brackets to both ends of the group (or individual module) using thescrews supplied (#440 pan-head screws). Next, secure the brackets to a flat surface using a #8 screwwith a lock washer.

The Nexus 1262/1272 will NOT supply power for the I/O modules. You must use an externalpower supply, such as the EIG PSIO (12V Output). Figure 6.12 shows the I/O Modules mountedwithout a PSIO Power Supply. Figure 6.15 shows mounting with the PSIO.

Figure 6.12: Nexus I/O Modules Mounting Diagram, Overhead View

Mounting Bracket

Mounting Bracket

Figure 6.13: Nexus I/O Module Communication Ports


I/O Port

Mounting Brackets (MBIO)

0.015” (0.37mm)

1.13” (28.57mm)3 x 1.32” (33.27mm)

4.1” (104.14mm)



Figure 6.14

Figure 6.15

Mounting Bracket (MBIO) Mounting Bracket (MBIO)

0.6” (15.24mm)

2x1.10” (27.93mm)

Y 1.31” (31.37mm)

1.25” (31.75mm)+YPer Module

3.44” (87.38mm)

2.20” (55.87mm)

Nexus I/O Modules Mounting Diagram, Front View

Nexus I/O Modules with PSIO Mounting Diagram, Front View

Y 1.31” (31.37mm)

X 1.73” (43.94mm)

0.6” (15.24mm)

3.44” (87.38mm)2x1.10” (27.93mm)

2.20”(55.87mm)

Mounting Bracket (MBIO)Mounting Bracket (MBIO)1.25” (31.75mm)+Y Per

Module+ X Per PSIO


Figure 6.16: I/O Wiring Detail

The Nexus 1262/1272 will NOT supply power for the optional external displays or the I/O modules.You must use an additional power supply, such as the EIG PSIO. The wiring is the same for allthe units. The only difference between the I/O Modules and the displays is that the port is on theside of the I/O Module (see Figure 11.1). The displays have the port on the back.

See Chapter 5 for communication details. See Figure 5.12 for wiring details.

Nexus I/O Wiring Diagram

Auxiliary Power (PSIO) issupplied through pins 4 & 5

Connection throughSHIELD, B- & A+ to Nexus 1262/1272 Port 4

(Detail) I/O Port


Chapter 7Nexus Time-oof-UUse

7.1: Introduction

A Time-of-Use (TOU) usage structure takes into account the quantity of energy used and the time atwhich it was consumed. The Nexus 1262/1272 TOU function, available with the CommunicatorEXT software, is designed to accommodate a variety of programmable rate structures. Nexus TOUaccumulates data based on the time-scheme programmed into the Nexus Meter.

See the Communicator EXT User Manual for details on programming the Nexus 1262/1272 TOUcalendar and retrieving TOU data.

7.2: The Nexus TOU Calendar

A Nexus TOU calendar sets the parameters for TOU data accumulation. You may store up to twentycalendars in the Nexus Meter and an unlimited amount of calendar files on your computer.

The Nexus TOU calendar profile allows you to assign a programmable usage schedule—eg,“Weekday,” “Weekend,” “Holiday”—to each day of the calendar year. You may create up to 16different TOU schedules.

Each TOU schedule divides the 24-hour day into fifteen-minute intervals from 00:00:00 to 23:59:59.You may apply one of eight different programmable registers—eg “Peak,” “Off Peak,” “ShoulderPeak”— to each fifteen-minute interval.

The Nexus Meter stores:

• accumulations on a seasonal basis, up to four seasons per year;

• accumulations on a monthly basis.

Seasonal and monthly accumulations may span one year into the next. Each season and month isdefined by a programmable start/billing date, which is also the end-date of the prior season or month.

• A season ends at midnight of the day before the start of the next season.

• A month ends at midnight of the month’s billing day.

If the year ends and there is no new calendar, TOU accumulations will stop. If a calendar is presentfor the following year, TOU accumulations continue until the next monthly bill date or next start-of-season is reached. Accumulation can span into the following year.

If no following year is present, the last accumulation for the year will end on 12:31:23:59:59.

Electro Industries/GaugeTech Doc #: E151-7-01 V1.01 7-2

7.3: TOU Frozen and Active Registers

The Nexus Meter stores accumulations for the prior time periods. When the end of a billing period isreached, the Active period of time becomes stored as Frozen. The registers are then cleared andaccumulations resume, using the next set of TOU schedules and register assignments from the storedcalendar.

Frozen and Active Accumulations are always available.

7.4: Updating, Retrieving and Replacing TOU Calendars

Communicator EXT software retrieves TOU calendars from the Nexus Meter or from the computer’s hard drive for review and edit.

Up to a maximum of twenty yearly calendars can be stored in the Nexus Meter at any given time.You may retrieve them one at a time; a new calendar can be stored while a current calendar is in use.

Accumulations do not stop during calendar updates. If a calendar is replaced while in use, the accumulations for the current period will continue until the set end date. At that point, the currenttime will become the new start time and the settings of the new calendar will be used.

Reset the current accumulations, if you replace a calendar in use. A reset clears only the currentaccumulation registers. This causes the current accumulations to use the present date as the start andaccumulate to the next new end date, which will be taken from the new calendar. Once stored, prioraccumulations are always available and can not be reset. See the Communicator EXT User Manualfor how to reset TOU accumulations.

At the end of a defined period, current accumulations are stored, the registers are cleared and accumulations for the next period begin. When the year boundary is crossed, the second calendar, ifpresent, is used. To retain continuity, you have up to one year to replace the old calendar with onefor the following year.

7.5: Daylight Savings and Demand

To use Daylight Savings Time, you must enable it in the Nexus Meter’s Device Profile, TimeSettings. Click Auto DST, which sets Daylight Savings Time automatically (for the United StatesONLY). You can also select User Defined and enter the desired dates for Daylight Savings Time.See the Communicator EXT User Manual for details.

To set Demand Intervals, from the Device Profile select Revenue & Energy Settings > DemandIntegration Intervals and set the desired intervals. Click OK.

To set Cumulative Demand Type, from the Device Profile click Revenue & Energy Settings >Cumulative Demand Type and select Block or Rolling Window. Click OK.


Chapter 8Transformer Loss Compensation

8.1: Introduction

The Edison Electric Institute’s Handbook for Electricity Metering, Ninth Edition defines LossCompensation as:

A means for correcting the reading of a meter when the metering point and point of service arephysically separated, resulting in measurable losses including I

2R losses in conductors and

transformers and iron-core losses. These losses may be added to or subtracted from the meterregistration.

Loss compensation may be used in any instance where the physical location of the meter does notmatch the electrical location where change of ownership occurs. Most often this appears whenmeters are connected on the low voltage side of power transformers when the actual ownershipchange occurs on the high side of the transformer. This condition is shown pictorially in Figure 8.1.

It is generally less expensive to install metering equipment on the low voltage side of a transformerand in some conditions other limitations may also impose the requirement of low-side metering eventhough the actual ownership change occurs on the high-voltage side.

The need for loss compensated metering may also exist when the ownership changes several milesalong a transmission line where it is simply impractical to install metering equipment. Ownershipmay change at the midway point of a transmission line where there are no substation facilities. Inthis case, power metering must again be compensated. This condition is shown in Figure 8.2.

M

Figure 9.1: Low Voltage Metering Installation Requiring Loss Compensation

Ownership Change

Figure 9.2: Joint Ownership Line Metering Requiring Loss Compensation

M

Point of Ownership Change

Figure 8.1: Low Voltage Metering Installation Requiring Loss Compensation

Figure 8.2: Joint Ownership Line Metering Requiring Loss Compensation


A single meter cannot measure the losses in a transformer or transmission line directly. It can however, include computational corrections to calculate the losses and add or subtract those losses tothe power flow measured at the meter location. This is the method used for loss compensation in theNexus meter.

The computational corrections used for transformer and transmission line loss compensation are similar. Generically, no-load losses and full-load losses are evaluated and a correction factor for eachloss level is calculated. However, the calculation of the correction factors that must be programmedinto the meter differ for the two different applications. For this reason, the two methodologies will betreated separately in this chapter.

In the Nexus meter, Loss Compensation is a technique that computationally accounts for active andreactive power losses. The meter calculations are based on the formulas below. These equationsdescribe the amount of active (Watts) and reactive (VARs) power lost due to both iron and coppereffects (reflected to the secondary of the instrument transformers).

Total Secondary Watt Loss =(((Measured Voltage/Cal point Voltage)

2x %LWFE) + ((Measured Current/Cal Point Current)2

x %LWCU)) x Full-scale Secondary VA

Total Secondary VAR Loss =(((Measured Voltage/Cal point Voltage)4 x %LVFE) + ((Measured Current/Cal Point Current)2

x %LVCU)) x Full-scale Secondary VA

The Values for %LWFE, %LWCU, %LVFE, %LVCU are derived from the transformer and meterinformation, as demonstrated in following sections.

The calculated loss compensation values are added to or subtracted from the measured Watts andVARs. The selection of adding or subtracting losses is made through the meter profile when programming the meter. The meter uses the combination of the add/subtract setting and the directional definition of power flow (also in the profile) to determine how to handle the losses.Losses will be "added to" or "subtracted from" (depending on whether add or subtract is selected)the Received Power flow. For example, if losses are set to "Add to" and received power equals 2000kW and losses are equal to 20kW then the total metered value with loss compensation would be2020 kW; for these same settings if the meter measured 2000 kW of delivered power the totalmetered value with loss compensation would be 1980 kW.

Since transformer loss compensation is the more common loss compensation method, the meter hasbeen designed for this application. Line loss compensation is calculated in the meter using the sameterms but the percent values are calculated by a different methodology as described in a subsequentsection below.

Nexus 1262/1272 Transformer Loss Compensation:• Performs calculations on each phase of the meter for every measurement taken. Unbalanced

loads are accurately handled.• Calculates numerically, eliminating the environmental affects that cause inaccuracies in

electromechanical compensators.


• Performs Bidirectional Loss Compensation.• Requires no additional wiring; the compensation occurs internally.• Imposes no additional electrical burden when performing Loss Compensation.

Loss Compensation is applied to 1 second per phase Watt/VAR readings and, because of that, affectsall subsequent readings based on 1 second per phase Watt/VAR readings. This method results in losscompensation be applied to the following quantities:• Total Power.• Demands, per phase and Total (Thermal, Block (Fixed) Window, Rolling (Sliding) Window and

Predictive Window).• Maximum and Minimum Demands.• Energy Accumulations.• KYZ Output of Energy Accumulations.

NOTE: Loss Compensation is disabled when the meter is placed in Test Mode.

8.2: Nexus 1262/1272 Transformer Loss Compensation

The Nexus meter provides compensation for active and reactive power quantities by performing thenumerical calculations using factors derived by clicking the TLC Calculator button on theTransformer Loss screen of the Device Profile or by manually figuring values in section 8.2.1,Calculating Transformer Loss Compensation Percentages (Work Sheet). Enter the derived values inthe Device Profile screen of the Communicator EXT software (values will automatically be enteredfrom the TLC Calculator button).

The Communicator EXT software allows you to enable Transformer Loss Compensation for Lossesdue to Copper and Iron, individually or simultaneously. Losses can either be added to or subtractedfrom measured readings.

Loss compensation values must be calculated based on the meter installation. As a result transformerloss values must be normalized to the meter by converting the base voltage and current and takinginto account the number of elements used in the metering installation. For three element meters, theinstallation must be normalized to the phase-to-neutral voltage and the phase current; in two elementmeters the installation must be normalized to the phase-to-phase voltage and the phase current. Thisprocess is described in the following sections.


8.2.1: Loss Compensation in Three Element Installations

Loss compensation is based on the loss and impedance values provided on the transformer manufacturer’s test report. A typical test report will include at least the following information:• Manufacturer• Unit Serial Number• Transformer MVA Rating (Self-Cooled)• Test Voltage• No Load Loss Watts• Load Loss Watts (or Full Load Loss Watts)• % Exciting Current @ 100% voltage• % Impedance

The transformer MVA rating is generally the lowest MVA rating (the self-cooled or OA rating) of thetransformer winding. The test voltage is generally the nominal voltage of the secondary or lowvoltage winding. For three phase transformers these values will typically be the three-phase ratingand the phase-to-phase voltage. All of the test measurements are based on these two numbers. Part ofthe process of calculating the loss compensation percentages is converting the transformer lossvalues based on the transformer ratings to the base used by the meter.

Correct calculation of loss compensation also requires knowledge of the meter installation. In orderto calculate the loss compensation settings you will need the following information regarding themeter and the installation:• Number of meter elements• Potential Transformer Ratio (PTR)• Current Transformer Ratio (CTR)• Meter Base Voltage • Meter Base Current

This section is limited to application of Nexus meters to three-element metering installations. As aresult, we know that:

• Number of metering elements = 3• Meter Base Voltage = 120 Volts• Meter Base Current = 5 amps

The loss compensation values can be calculated by clicking the TLC Calculator button on theTransformer Loss screen of the Nexus Device Profile (MS Excel Spreadsheet) or by completing theworksheet “Three Element Loss Compensation Worksheet” below. In order to activate the ExcelSpreadsheet, you must have MS Excel installed on your computer.

NOTE: A copy of the Excel Spreadsheet with Example Numbers can be found in Appendix A of this manual.


8.2.1.1: Three Element Loss Compensation Worksheet

Transformer Data (from Transformer Manufacturer’s Test Sheet)

Enter 3-Phase or 1-Phase values. If 3-Phase values are entered, calculate 1-Phase values by dividing 3-Phase values by three. Convert 1-Phase Loss Watts to 1-Phase kW by dividing 1-Phase Loss Watts by1000.

Enter 3-Phase or 1-Phase values. If 3-Phase values are entered, calculate 1-Phase values by dividing 3-Phase values by three. Convert 1-Phase Self-Cooled MVA to 1-Phase kVA by multiplying by 1000.

Test Voltage is generally Phase-to-Phase for three-phase transformers. Calculate Phase-to-Neutral Voltage by dividing Phase-to-Phase Voltage by √3. Calculate Full Load Current by dividing the (1-PhasekW Self-Cooled Rating) by the (Phase-to-Neutral Voltage) and multiplying by 1000.

Company

Date

Trf Manf

Calculation by

Station Name

Trf Bank No.

Trf Serial No.

ConnectionWinding Voltage MVA

HV - High ∆ - Y

Xv - Low

YV - Tertiary

∆ - Y

∆ - Y

Watts Loss

1-Phase3-Phase 1-Phase kWValue

No-Load Loss

Load Loss

Value 3-Phase MVA 1-Phase MVA 1-Phase kVA

Self-Cooled Rating

% Exciting Current

% Impedance

Value Phase-to-Phase Phase-to-Neutral

Test Voltage (volts)

Full Load Current (Amps)


Meter/Installation Data

Enter the Numerator and Denominator for each instrument transformer. For example, a PT with a ratioof 7200/120 has a numerator or 7200, a denominator or 120 and a multiplier of 60 ( 7200/120 = 60/1).

Base Conversion Factors

For Transformer Voltage, enter the Phase-to-Neutral value of Test Voltage previously calculated. For Transformer Current, enter the Full-Load Current previously calculated. For Multipliers, enter the PTand CT multipliers previously calculated. TrfIT Secondary is the Base Value of Voltage and Current at the Instrument Transformer Secondary of the Power Transformer. These numbers are obtained by dividing the Transformer Voltage and Current by their respective Multipliers. The Meter/Trf values for Voltage and Current are obtained by dividing the Meter Base values by the TrfIT Secondary values.

Load Loss at TransformerNo-Load Loss Watts (kW) = 1-Phase kW No-Load Loss = ______________

No-Load Loss VA (kVA) = (%Exciting Current) * (1-Phase kVA Self-Cooled Rating) / 100

= (______________) * (________________) / 100

= _______________ kVA

No-Load Loss VAR (kVAR) = SQRT((No-Load Loss kVA)2 - (No-Load Loss kW)2)

= SQRT((_________________)2 - (________________)2)

= SQRT((__________________) - (_________________))

= SQRT (_________________)

= ____________________

Instrument Transformers Numerator Denominator Multiplier

Potential Transformer

Current Transformer

Power Multiplier [(PT Multiplier) times (CT Multiplier)]

Meter Secondary Voltage (volts) 120

Meter Secondary Current (amps) 5

Quantity

Voltage

Current

Transformer Multiplier Trf IT Sec Meter Base Meter/Trf

120

5


Full-Load Loss Watts (kW) = 1-Phase Kw Load Loss = ______________

Full-Load Loss VA (kVA) = (%Impedance) * (1-Phase kVA Self-Cooled Rating) / 100

= (______________) * (________________) / 100

= _______________ kVA

Full-Load Loss VAR (kVAR) = SQRT((Full-Load Loss kVA)2 - (Full-Load Loss kW)2)

= SQRT((_________________)2 - (________________)2)

= SQRT((__________________) - (_________________))

= SQRT (_________________)

= _________________

Normalize Losses to Meter Base

Enter Value at Transformer Base for each quantity from calculations above. Enter Meter/Trf Factorvalue from Base Conversion Factor calculations above. Calculate M/T Factor with Exponent by raisingthe M/T Factor to the power indicated in the “Exp” (or Exponent) column. Calculate the “Value at Meter Base” by multiplying the (M/T Factor w/ Exp) times the (Value at TrfBase).

Loss Watts Percentage ValuesMeter Base kVA = 600 * (PT Multiplier) * (CT Multiplier) / 1000

= 600 * (____________) * (___________) / 1000

= ________________

Quantity

No-Load Loss kW

Value at TrfBase

M/TFactor

M/T FactorValue

V

V

I

I

Exp M/T Factor w/Exp

Value atMeter Base

No-Load Loss kVAR

Load Loss kW

Load Loss kVAR

∧2∧4∧2∧2


Calculate Load Loss Values

Enter “Value at Meter Base” from Normalize Losses section. Enter “Meter Base kVA” from previous calculation. Calculate “% Loss at Meter Base” by dividing (Value at Meter Base) by (Meter Base kVA)and multiplying by 100.

Enter calculated % Loss Watts values into Nexus meter using Communicator software.

Quantity Value at MeterBase

Meter BasekVA

% Loss atMeter Base Quantity

% Loss Watts FE

% Loss VARs FE

% Loss Watts CU

% Loss VARs CU

No-Load Loss kW

No-Load Loss kVAR

Load Loss kW

Load Loss kVAR

Chapter 9Using the Nexus External Displays

9.1: Overview

The Nexus 1262/1272 Socket Meters have a backlit LCD display built into the meter. In addition,Electro Industries offers two optional external displays, each powered by an additional power supply(such as PSIO). The P40N is our LED display, which provides easy-to-use access to the informationstored in the Nexus. The P60N is our Touch Screen Display, which provides easy access to Nexusreadings and information combined with a graphical touch screen presentation.

Plug one of the Nexus External Displays into the Port 1 or Port 4 wiring connection using the RS-485 cable supplied (see Figure 6.11 for wiring details). The Displays operate at 9600 baud. Touse the Displays on another port, configure that port to operate at 9600 baud, using theCommunicator EXT Software; see the Communicator EXT User Manual.

9.2: Nexus P40N LED External Display

The Nexus P40N LED External Display has three modes:

• Dynamic Readings Mode (section 9.3 and 9.4)• Nexus Information Mode (section 9.5 and 9.6)• Display Features Mode (section 9.7 and 9.8)

Each Mode is divided into Groups. Most Groups are further broken down into Readings.

• Use the MODE button to scroll between Modes.• Use the UP/DOWN arrows to scroll from Group to Group within each Mode.• Use the LEFT/RIGHT arrows to scroll from Reading to Reading within each Group.

Use Communicator EXT software to Flash Update the P40N External Display. VA Rating is 5.


LED Display

Up/Down Arrows

Mode Button

Left/Right Arrows

Figure 9.1: Nexus P40N LED External Display


9.3: Dynamic Readings Mode

The External Display puts itself in the Dynamic Readings Mode upon power-up. Use the MODEbutton to access the Dynamic Readings from other Modes. Use the UP/DOWN arrows to navigatefrom Group to Group within this Mode. See section 9.4 for a navigational map of the DynamicReadings Mode.

Group 1: Phase to Neutral Voltages (Use the LEFT/RIGHT arrows to access the following readings, in order.)

• Volts AN/BN/CN• Maximum Volts AN/BN/CN• Minimum Volts AN/BN/CN• Volts AN/BN/CN %THD• Volts AN/BN/CN Maximum %THD• Volts AN/BN/CN Minimum %THD

Group 2: Phase to Phase Voltages (Use the LEFT/RIGHT arrows to access the following readings,in order.)

• Volts AB/BC/CA• Maximum Volts AB/BC/CA• Minimum Volts AB/BC/CA

Group 3: Current (Use the LEFT/RIGHT arrows to access the following readings, in order.)

• Current A/B/C• Maximum Current• Minimum Current• Current %THD• Current Maximum %THD• Current Minimum %THD• Current Calculated N/Measured N• Maximum Current Calculated N/Measured N

Group 4: Watt/VAR (Use the LEFT/RIGHT arrows to access the following readings, in order.)

• kWatt/kVAR• Maximum +kWatt/+kVAR/CoIn kVAR• Maximum -kWatt/-kVAR/CoIn kVAR• Fixed (Block) Window Average Maximum +kWatt/+kVAR/CoIn kVAR• Predictive Sliding (Rolling) Window Maximum +kWatt/+kVAR/CoIn kVAR

Group 5:VA/PF/Frequency (Use the LEFT/RIGHT arrows to access the following readings, inorder.)

• kVA/PF lag/Hz• Maximum kVA/Hz• Minimum kVA/Hz

• Maximum Quadrant 1 Total PF• Minimum Quadrant 1 Total PF• Maximum Quadrant 2 Total PF• Minimum Quadrant 2 Total PF• Maximum Quadrant 3 Total PF• Minimum Quadrant 3 Total PF• Maximum Quadrant 4 Total PF• Minimum Quadrant 4 Total PF

Group 6: Delivered Energy (Use the LEFT/RIGHT arrows to access the following readings, inorder.)

• +kWatthr Quadrant 1+Quadrant 4 (Primary)• +kVAhr Quadrant 1 (Primary)• +kVARhr Quadrant 1 (Primary)• +kVAhr Quadrant 4 (Primary)• -kVARhr Quadrant 4 (Primary)

Group 7: Received Energy (Use the LEFT/RIGHT arrows to access the following readings, inorder.)

• -kWatthr Quadrant 2+Quadrant 3 (Primary)• +kVAhr Quadrant 2 (Primary)• +kVARhr Quadrant 2 (Primary)• +kVAhr Quadrant 3 (Primary)• -kVARhr Quadrant 3 (Primary)

Group 8: Accumulations (Use the LEFT/RIGHT arrows to access the following readings, in order.)

• kI2t A

• kI2t B

• kI2t C

• kV2t A

• kV2t B

• kV2t C

Group 9: Phase Angles (Use the LEFT/RIGHT arrows to access the following readings, in order.)

• Phase Angle Van/bn/cn• Phase Angle Ia/b/c• Phase Angle Vab/bc/ca• Phase Sequence


1 Second VoltsAN,BN,CN

Maximum VoltsAN,BN,CN

Maximum VoltsAB,BC,CA

Minimum VoltsAB,BC,CA

Minimum VoltsAN,BN,CN

%THD VoltsAN,BN,CN

Max %THDVolts

AN,BN,CN

Min %THDVolts

AN,BN,CN

Return toFirst

Reading

Return toFirst

Reading

Return toFirst

Reading

Return toFirst

Reading

Return toFirst

Reading

Return toFirst

Reading

Return toFirst

Reading

Return to FirstReading

Return toFirst

Reading

1 Second VoltsAB,BC,CA

1 SecondkWatt, kVAR

+Max kWatt,+kVAR,CoIn

kVAR

-Max kWatt,-kVAR,CoIn

kVAR

Block WinAvg Max+kWatt,

+kVAR,CoIn kVAR

Pred Roll Win Avg+kWatt,

+kVAR,CoIn kVAR

1 SecondIA,IB,IC

MaximumIA,IB,IC

MinimumIA,IB,IC

%THDIA,IB,IC

Max %THDIA,IB,IC

Min %THDIA,IB,IC

1 SecondINc,INm

1 SecondkVA, PF

lag,Frequency

MaxkVA,Freq

MinkVA,Freq

Max Q1,Total PF

Min Q1,Total PF

Max Q2,Total PF

Min Q2,Total PF

Max Q3,Total PF

Min Q3,Total PF

Min Q4,Total PF

Min Q4,Total PF

PositivekWatthour

Q1+Q4

PositivekVAhr

Q1

PositivekVAhr

Q2

PositivekVARhr

Q1

PositivekVARhr

Q2

PositivekVAhr

Q4

PositivekVAhr

Q3

NegativekVARhr

Q4

NegativekVARhr

Q3

kI2t A kI

2t B kI

2t C kV

2t A kV

2t B kV

2t C

Phase Angles VAN,BN,CN

Phase Angles IA,B,C

Phase Angles VAB,BC,CA

PhaseSequence

Groups

9.4: Navigational Map of Dynamic Readings Mode

Use LEFT/RIGHT arrow keys to navigate Readings

Use UP/DOWN arrows to scroll between groups.

EElleeccttrroo IInndduussttrriieess//GGaauuggeeTTeecchh Doc # E151-7-01 V1.01 9-4

Negative kWatthrQ2+Q3

9.5: Nexus Information Mode

Use the MODE button to access the Nexus Information Mode from other Modes. Use theUP/DOWN arrows to navigate from Group to Group within this Mode. See section 9.6 for a navigational map of the Nexus Information Mode.

Group 1: Device Time

• Meter Time

Group 2: Communication Settings (Use the LEFT/RIGHT arrows to access the following readings,in order.)

• Communication Settings Port 1: Baud/Addr/Protocol• Communication Settings Port 2: Baud/Addr/Protocol• Communication Settings Port 3: Baud/Addr/Protocol• Communication Settings Port 4: Baud/Addr/Protocol

Group 3: PT, CT Ratios (Use the LEFT/RIGHT arrows to access the following readings, in order.)

• PT Ratio• CT Ratio

Group 4: External Display Units

• Primary/Secondary

• Select either Primary or Secondary units for the External Display using the Communicator EXTsoftware (see the Communicator EXT User Manual).When Primary is selected, the Displayshows all readings in Primary units based on the user programmed PT and CT Ratios. WhenSecondary is selected, the Display shows all readings in Secondary units.

Group 5: Firmware Versions and Serial Numbers (Use the LEFT/RIGHT arrows to access thefollowing readings, in order.)

• RunTime External Display/RunTime DSP/RunTime Comm• Boot External Display/Boot DSP/Boot Comm• Serial Number External Display; Serial Number Nexus Meter


Meter Time

DisplayPrimary/Secondary

CT RatioPT Ratio

Serial #Display, Serial

# Monitor

BootDisplay,

DSP, Comm

Run-timeDisplay,

DSP, Comm

Groups

Readings

Return To

First Reading

Return To

FirstReading

9.6: Navigational Map of Information Mode


Use LEFT/RIGHT arrows to scroll between readings.


Return To

First Reading

CommSettingsPort 4

CommSettingsPort 3

Comm SettingsPort 2

CommSettingsPort 1

9.7: Display Features Mode

Use the MODE button to access the Display Features Mode from other Modes. Use the UP/DOWNarrows to navigate from Group to Group within this Mode. See section 9.8 for a navigational map ofthe Display Features Mode.

Group 1: Reset Max/Min

• Note: If the password protection feature has been enabled with the Communicator EXTsoftware, you will need to enter a password to reset the max/min readings. To do this, first pressthe Enter button. Then enter the password, one character at a time, by pressing on the UP orDOWN arrows. Each password character begins as an “A”. Press the UP arrow to increment thecharacter from “A–Z” and then from “0–9”. Press the DOWN arrow to decrement the characterfrom “A” to “9–0” and then from “Z–A”. Press SET to enter each character the password. Whenthe entire password is shown on the Display screen, press ENTER. If the password is correct youmay then press Enter again to Reset the Energy readings.

• Press the Enter button to reset the Max and Min values.

Group 2: Reset Energy

• Note: If the password protection feature has been enabled with the Communicator EXTsoftware, you will need to enter a password to reset the energy. To do this, first press the Enterbutton. Then enter the password, one character at a time, by pressing on the UP or DOWNarrows. Each password character begins as an “A”. Press the UP arrow to increment the character from “A–Z” and then from “0–9”. Press the DOWN arrow to decrement the characterfrom “A” to “9–0” and then from “Z–A”. Press SET to enter each character the password. Whenthe entire password is shown on the Display screen, press ENTER. If the password is correct youmay then press Enter again to Reset the Energy readings.

• Press Enter button to reset the Max and Min values.

Group 3: Display Baud Rate/Address

Group 4: Display Communication Protocol

Group 5: EIG Use Only

Group 6: EIG Use Only

Group 7: Lamp Test

• Press Enter to conduct an LED test.

Group 8: Display Scroll ON/OFF

• Press Enter to turn the scroll feature on or off. When the scroll feature is on, the P40N ExternalDisplay will scroll through the first reading of each group in the Dynamic Readings Mode. If abutton is pressed during the scroll, scrolling pauses for one minute.


Reset Max/Min

Reset Energy

CommunicationProtocol

BaudRate/Address

EIG Use Only

EIG Use Only

Display ScrollOn/Off

Groups

9.8: Navigational Map of Display Features Mode



Lamp Test

9.9: Nexus P60N Touch Screen External Display

The P60N Touch Screen External Display is ready to use upon power-up. Touching the “buttons” atthe top of the screen will take you to the Groups of Readings listed below. With the “buttons” atthe bottom of the screen, you can use the touch screen to review Limits and review and/or changeSettings on the Display and the Nexus Meter. Also, you can Reset Max/Min and Demand, Hour, I2Tand V2T Counters, All Logs and TOU for Current Session and Month using the Reset Button.The P60N has a VA Rating of 5 and is powered by an external power source, such as the PSIO. SeeFig.s 6.9, 6.11 for wiring detail. NOTE: The P60N DOES NOT support TOU in 1262/1272 meters.

All screens have a Main button that will take you back to the Main screen. All screens also have aNext button that will take you to the next group of readings. Some of the screens have additionalnavigation buttons to take you to complimentary readings. See section 9.10 for a navigational map.

VOLTS: Voltage Readings Details

• Volts AN/BN/CN/AB/BC/CA• Maximum Volts AN/BN/CN/AB/BC/CA• Minimum Volts AN/BN/CN/AB/BC/CA


Groups of Readings

Reset Button

View Limits View / Change Settings

Figure 9.2: Nexus P60N Touch Screen External Display

AMPS: Current Readings Details

• Real Time Current A/B/C• Maximum Current A/B/C• Minimum Current A/B/C• Current Calculated N/Measured N• Maximum Current Calculated N/

Measured N

REAL TIME POWER: Real Time PowerReadings Details (Demand button goes toDemand Power screen.)

• Instant kWatt/kVAR/VA/PF• Average kWatt/kVAR/VA/PF• Predicted kWatt/kVAR/VA/PF

DEMAND POWER: Demand Power ReadingsDetails (R/T button goes to Real Time Power screen.)

• Thermal Window Average Maximum+kWatt/+kVAR/CoIn kVAR

• Fixed (Block) Window Average Maximum+kWatt/+kVAR/CoIn kVAR

• Predictive Sliding (Rolling) Window Maximum+kWatt/+kVAR/CoIn kVAR

ENERGY: Accumulated Energy Information/Delivered Energy/Received Energy (TOU buttongoes to TOU Register Accumulations screen.)

• -kWatthr Quadrant 2+Quadrant 3 (Primary)• +kVAhr Quadrant 2 (Primary)• +kVARhr Quadrant 2 (Primary)• +kVAhr Quadrant 3 (Primary)• -kVARhr Quadrant 3 (Primary)• +kWatthr Quadrant 1+Quadrant 4 (Primary)• +kVAhr for all Quadrants (Primary)


TOU: Time of Use Readings RegisterAccumulations/ Registers 1 - 8 (Demand button goes to TOU Register Demand screen.) (Next Reg button displays Registers 1 - 8.) (Next Group button displays Prior Season, Month, Current Season, Month.)

• -kWatthr Quadrant 2+Quadrant 3 (Primary)• +kVAhr Quadrant 2 (Primary)• +kVARhr Quadrant 2 (Primary)• +kVAhr Quadrant 3 (Primary)• -kVARhr Quadrant 3 (Primary)• +kWatthr Quadrant 1+Quadrant 4 (Primary)• +kVAhr Quadrants 1 & 4 (Primary)• -kVARhr Quadrant 4 (Primary)

Register Demand/ Register 1 - 8 (Accum buttongoes to TOU Register Accumulation screen.) NextReg button displays Registers 1 - 8.) (Next Groupbutton displays Prior Season, Month, Current Season,Month.)

• Fixed Window +kWatth, +kVARhr, -kWatth, -kVARh, Coin +kVARh, Coin -kVARh

PHASORS: Phasor Analysis

• Phase Angle Van/bn/cn• Phase Angle Ia/b/c• Phase Angle Vab/bc/ca

WAVEFORM: Real Time Waveform Graph. Use Channel button to view graphs and readings:

• Channel Van/bn/cn• Channel Ia/b/c• % THD, KFactor, Frequency for

selected channel


SPECTRUM: Harmonic Spectrum Analysis. Use Channel button to view graphs and readings:Zoom In or Out for detail.

• Channel Van/bn/cn• Channel Ia/b/c• % THD, KFactor, Frequency for

selected channel

LIMITS: Limit Status. Current Limits Settings for Nexus Meter, ID 1 - 32. Use Next Group Button to view next settings.

RESET: Meter Reset Commands. To Change Settings for following: Touch the screen to change Don’t Reset to Reset. Touch Reset Now button. OK will appear. Touch OK to refresh screen (go back to original screen).

• Max/Min and Demand.• Hour, I2T and V2T Counters.• All Logs.• TOU for Current Session and Month.

SETTINGS:

• LCD Screen Settings: Contrast. Touch Up/Down buttons toincrease/decrease settings. Number 37 is optimum setting.Backlight Off Delay (number of seconds after use that backlight turns off - 1 to 999. A setting of 0 keeps the Back Light ON). Touch Up/Down buttons to increase/decrease settings.


• Nexus Link Settings: Nexus Address (000 - 255). Touch Up/Down buttons to increase/decrease settings.Protocol (selected).Baud (selected).

To Add an Address: Click UP to Add an Address.SAVE Button will appear.Click SAVE to Save the New Address.

• Nexus Port Settings: Port 1 (Baud and Protocol selected).Port 2 (Baud and Protocol selected).Port 3 (Baud and Protocol selected).Port 4 (Baud and Protocol selected).

• Nexus Status:Device Type: Nexus 1250Serial Number (10 digit number)Comm State: Healthy or UnhealthyNv Ram: 4 MBDSP State: Healthy or UnhealthyProtection: Password Enabled or DisabledOn Time: Current Date and Time

• Firmware Versions:Nexus 1250

Boot: Run-time: DSP Boot: DSP Run-time:

LCD Display:

This screen displays the current firmware version for the Nexus and the display.


MENU

LCD ScreenSettings

Meter ResetCommands

VoltageReadings Details

CurrentReadings Details

Real TimePower Readings

Details

Demand PowerReadings Details

AccumulatedEnergy

Information

Time of UseReadingsRegister

Accumulations

Time of UseReadingsRegisterDemand

Phasor Analysis Real TimeWaveform Graph

HarmonicSpectrumAnalysis

Limits

Port SettingsStatus

FirmwareVersions Link Settings

NEXTNEXT

NEXT NEXT

NEXT

VOLTS

NEXT

NEXT

AMPS

REAL TIMEPOWER

SETTINGS

DEMAND R/T

TOU

DEMAND ACCUM

NEXT

NEXT NEXT

NEXT

NEXT

NEXT

NEXT

DEMANDPOWER

ENERGY

TOU

PHASORS WAVEFORM

SPECTRUM

LIMITS

RESET

NEXT

NEXT

Doc #: E151-7-01 V1.01 Electro Industries/GaugeTech 9-14

9.10: Navigational Map for P60N Touch Screen External Display

9.11: Optional P40N LED External Remote Display Specifications

9.12: Optional P60N Touch Screen Remote Display Specifications


Specification P40N LED External Specification

Maximum Input Voltage 30VdcMinimum Input Voltage 7Vdc

VA Rating 8 VA

Nominal Power Consumption Approximately 6 Watts

Operating Temperature Range (-20 to +60)oC / (-4 to +140)oF

Overall Dimensions (HxWxL) 2.2 x 4.4 x 4.4 in / 5.9 x 11.1 x 11.1 cm

P60N Touch Screen DisplaySpecification

Maximum Input Voltage

Minimum Input Voltage

VA Rating

Nominal Power Consumption

Operating Temperature Range

Overall Dimensions (HxWxL)

30Vdc10Vdc8 VA

Approximately 4.5 Watts

(0 to +50)oC / (+32 to +122)oF

1.6 x 5.4 x 8.0 in / 4.0 x 13.7 x 20.3 cm


Chapter 10Nexus External I/O Modules

10.1: Hardware Overview

All Nexus External I/O modules have the following components:

•• Female RS-485 Side Port: use to connect to another module’s male RS-485 side port.

•• Male RS-485 Side Port: use to connect to the Nexus’s Port 4 or to another module’s female RS-485 side port. See Figure 10.2 for wiring detail.

•• I/O Port: used for functions specific to the type of module; size and pin configuration varydepending on type of module.

•• Reset Button: Press and hold for three seconds to reset the module’s baud rate to 57600 and itsaddress to 247 for 30 seconds.

•• LEDs: when flashing, signal that the module is functioning.

•• Mounting Brackets (MBIO): used to secure one or more modules to a flat surface.

I/O Port(Size and pin

configuration vary)



Integrated Fastening System

Mounting Brackets (MBIO)

LEDs

Reset Button

Figure 10.1: I/O Module Components


10.1.1: Port Overview

All Electro Industries I/O Modules have ports through which they interface with other devices. The port configurations are variations of the four types shown below.

Four Analog Outputs Eight Analog Outputs (0-11mA and 4-220mA) (0-11mA and 4-220mA)

Eight Analog Inputs Four Relay Outputs (0-11mA, 0-220mA, or Four KYZ Pulse Outputs0-55Vdc, 0-110Vdc)

or Eight Status Inputs


10.2: Installing Nexus External I/O Modules

I/O modules must use the Nexus 1262/1272 Meter’s Port 4. Six feet of RS-485 cable harness is supplied. Attach one end of the cable to the port (connectors may not be supplied); insert the otherend into the communication pins of the module’s Male RS-485 Side Port. Follow steps below andsee Figure 10.2 below. See section 10.3 for details on using multiple I/O modules.

Figure 10.2: Nexus Meter Connected to I/O Module

RT

RT *

(For runs typically longer than 500 feet)

Male Side Porton Nexus I/OModule

Nexus1262/1272

Port 4

LED’s

* NOTE: Termination Resistors are only needed with runs typically more than 500 feet. The meterhas some level of termination internally and usually resistors are not needed.


10.2.1: Power Source for I/O Modules

The Nexus 1262/1272 units will NOT SUPPLY POWER TO THE I/O MODULES. You must usean external power source, such as the EIG PSIO (12V). Rule of thumb is 1 Power Source for every 4 I/O Modules. RS-485 communication is viable forup to 4000 feet (1219 meters). Below are the dimensions and the labels for the PSIO.

You must also do the following:

• Connect the A(+) and B(-) terminals on the Nexus to the A(+) and B(-) terminals of the maleRS-485 port. Connect the shield to the shield (S) terminal. The (S) terminal on the Nexus isused to reference the Nexus port to the same potential as the source. It is not an earth ground connection. You must also connect the shield to earth-ground at one point.

• Put termination resistors at each end, connected to the A(+) and B(-) lines. RT is ~120 Ohms.

Figure 10.5: Labels for thePSIO Power Source

(Labels are Red & White.)

Figure 10.3: The PSIO Power Source (Side View) showing Male RS-485 Side Port

Figure 10.4: Power flow from PSIO to I/O Module

SIDE LABEL

TOP LABEL

1.72”

4.08” 3.42”


Mounting Bracket

Male RS-485Side Port

FemaleRS-485

Side Port

LEDs

I/O Port (Size and pin configuration vary)

Reset Button

10.3: Using Multiple I/O Modules

10.3.1: Steps for Attaching Multiple I/O Modules

1. Each I/O module in a group must be assigned a unique address. See the Communicator EXTUser Manual for details on configuring and programming the I/O Modules.

2. Determine how many power sources (such as PSIO) are needed for the number of modules in use.See section 10.2.1 for details.

Figure 10.6: Multiple I/Os

I/Os must use the Nexus 1262/1272 Meter’s Port 4.Set the port to 57600 Baud, Master.

RS-485 Cable

Addr160

Addr128

Addr156

Group of 3 I/OsExternal

Power Source


3. Starting with the left module and using a slotted screw driver, fasten the first I/O Module to the left Mounting Bracket. The left Mounting Bracket is the one with the PEM. Fasten the internal screw tightly into the left Mounting Bracket.

4. Next, slide the female RS-485 port into the male RS-485 side port to connect the next I/O module to the left module. Fasten together enough to grab but do not tighten.One by one combine the modules together using the Integrated Fastening System (Fig. 10.1). If you require an additional power supply, attach a PSIO (power supply) to the right of each group of 4 I/O Modules (section 10.3).

NOTE: The PB1 can also be used for a Low Voltage Power Supply. It must be mounted separately.

5. Once you have combined all the I/O modules together for the group, fasten tightly. This final tightening will lock the whole group together as a unit.

6. Attach the right Mounting Bracket to the right side of the group using small phillips head screws provided.

7. Then, mount the group of modules on a secure, flat surface. This procedure will ensure that all modules stay securely connected.

10.4: Factory Settings and Reset Button

Factory Settings:All Nexus I/O Modules are shipped with a preset address and a baud rate of 57600. See below foraddresses.

Reset Button:If there is a communication problem or if you are unsure of a module’s address and baud rate, pressand hold the RESET button for 3 seconds; the module will reset to a default address of 247 at 57600baud rate for 30-seconds. This will enable you to interrogate the I/O using the Communicator EXTsoftware; see the Modbus Communicating I/O Modules User Manual.

Model # Module Factory-Set Address

1mAON4 0±1mA, 4-Channel Analog Output 1281mAON8 0±1mA, 8-Channel Analog Output 12820mAON4 4–20mA, 4-Channel Analog Output 13220mAON8 4–20mA, 8-Channel Analog Output 132

8AI1 0±1mA, 8-Channel Analog Input 1368AI2 0±20mA, 8-Channel Analog Input 1408AI3 0±5Vdc, 8-Channel Analog Input 1448AI4 0±10Vdc, 8-Channel Analog Input 1484RO1 4 Latching Relay Outputs 1564PO1 4 KYZ Pulse Outputs 1608DI1 8 Digital Status Inputs (Wet/Dry) 164


10.5: Analog Transducer Signal Output Modules

10.5.1: Overview

The Analog Transducer Signal Output Modules (0±1mA or 4–20mA) are available in either a 4- or8-channel configuration. Maximum registers per request, read or write, is 17 registers.

Nexus 1262/1272 Unit DOES NOT supply power for the Analog Output modules. See section 10.2 for power and communication details.

All outputs share a single common point. This is also an isolated connection (from ground).

Analog Transducer Signal Output Modules Specifications

Accuracy

Communication

Power Requirement

Operating Temperature

Maximum Load Impedance

RS-485, Modbus RTU

15–20Vdc at 50–200mA;Nexus 1262/1272 Unit

DOES NOT Support I/O Modules

(-20 to 79)°C / (-4 to +158)°F

0±1mA: 10k Ω; 4–20mA: 500 Ω

Model Numbers

1mAON4: 4-Channel Analog Output, 0±1mA

1mAON8: 8-Channel Analog Output, 0±1mA

20mAON4: 4-Channel Analog Output, 4–20mA

20mAON8: 8-Channel Analog Output, 4–20mA

Factory Settings

Modbus Address:1mAON4, 0-1mA: 128 1mAON8, 0-1mA: 128

20mAON4, 4–20mA: 132, 20mAON8, 4-20mA: 132

Baud Rate: 57600

Default Settings(Reset Button)

Modbus Address: 247

Baud Rate: 57600

Programmable Baud Rates: 4800, 9600, 19200, 57500

0.1% of Full Scale

Scaling Programmable

Transmit Delay Time: 0

Transmit Delay Time: 20 csec


The Modbus Map for the Analog Output Module (and operating details) can be found in the ModbusCommunicating I/O Modules Manual.

10.5.2: Normal Mode

Normal Mode is the same for the 0-1mA and the 4-20mA Analog Output Modules except for thenumber of processes performed by the modules.

Both devices:

1. Accept new values through communication.2. Output current loops scaled from previously accepted values.

The 0-1mA module includes one more process in its Normal Mode:

3. Read and average the A/D and adjust values for Process 2 above..

The device will operate with the following default parameters:

Address 247 (F7H)Baud Rate 57600 BaudTransmit Delay Time 0

Normal Operation is prevented by a number of occurrences. See section 10.4.1 for details.



10.6: Analog Input Modules

Analog Input Modules Specifications

Model Numbers

8AI1: 8-Channel Analog Input, 0±1mA

8AI2: 8-Channel Analog Input, 0±20mA

8AI3: 8-Channel Analog Input, 0±5Vdc

8AI4: 8-Channel Analog Input, 0±10Vdc

Accuracy 0.1% of Full Scale

Scaling Programmable

CommunicationRS-485, Modbus RTU

Programmable Baud Rates: 4800, 9600, 19200,57600

Power Requirement15-20Vdc at 50-200mA;Nexus 1262/1272 Unit


Operating Temperature (-20 to 79)°C / (-4 to +158)°F

Maximum LoadImpedance 0-1mA: 10k Ω; 4-20mA: 500 Ω

Factory Settings

Modbus Address:8AI1, 0±1mA: 136; 8AI2, 0±20mA: 1408AI3, 0±5Vdc: 144, 8AI4, 0±10Vdc: 148

Baud Rate: 57600

Modbus Address: 247

Baud Rate: 57600

10.6.1: Overview

The Analog Input Modules (0±1mA, 0±20mA, 0±5Vdc and 0±10Vdc) are available in 8-channel format. Maximum registers per request, read or write, is 17 registers.

Nexus 1262/1272 Unit DOES NOT SUPPORT I/O MODULES. See section 10.2 for power andcommunication details. Refer to section 10.2.1 for power source details.

All inputs share a single common point. This is also an isolated connection (from ground).





10.6.2: Normal Mode

In Normal Mode, the Input Module:

1. Reads and averages the A/D and adjusts values for process 2.2. Calculates the percentage of Input Value.

NOTE: The percentage value of the Input will be stored in Input Value Registers (Registers 04097-04104).

.The device will operate with the following default parameters:

Address 247 (F7H)Baud Rate 57600 BaudTransmit Delay Time 0

Normal Operation is prevented by a number of occurrences. See section 10.4.1 for details.


10.7: Digital Dry Contact Relay Output (Form C) Module

Digital Dry Contact Relay Output (Form C) Module Specifications

Model Number

Communication

Power Requirement


Maximum Load Impedance

4RO1: 4 Latching Relay Outputs

RS-485, Modbus RTU


15–20Vdc at 50–200 mA;Nexus 1262/1272 Unit


(-20 to 79)°C / (-4 to +158)°F

0-1mA: 10k Ω; 4-20mA: 500 Ω

Factory Settings

Modbus Address: 156

Baud Rate: 57600


Modbus Address: 247

Baud Rate: 57600

10.7.1: Overview

The Relay Output Module consists of four Latching Relay Outputs. In Normal Mode, the deviceaccepts commands to control the relays. Relay output modules are triggered by limits programmedwith the Communicator EXT software. See the Communicator EXT User Manual for details on programming limits.

Nexus 1262/1272 Unit DOES NOT SUPPORT I/O MODULES. A power source is required. Seesection 10.2 for power and communication details.


Each latching relay will hold its state in the event of a power loss.



Programmable

Accuracy

Scaling

0.1% of Full Scale


10.7.2: Communication

Maximum registers per request, read or write, is 4 registers.orm

The device will operate with the following Default Parameters:Address 247 (F7H)Baud Rate 57600 BaudTransmit Delay Time 20 csec

Some situations will cause the device to operate with the above Default Parameters. See section10.4.1 for details of Default Mode.

10.7.3: Normal Mode

Normal Mode consists of one process:

1. The device accepts new commands to control the relays.


10.8: Digital Solid State Pulse Output (KYZ) Module

Digital Solid State Pulse Output (KYZ) Module Specifications

Model Number

Communication

Power Requirement


Memory

Factory Settings


4PO1

RS-485, Modbus RTU


(-20 to 79)°C / (-4 to +158)°F



256 byte I2C EEPROM

for storage of Programmable Settings and Nonvolatile Memory

Modbus Address: 160

Baud Rate: 57600

Modbus Address: 247

Baud Rate: 57600

10.8.1: Overview

The KYZ Pulse Output Modules have 4 KYZ Pulse Outputs and accept Read and Write Commandswith at least 4 registers of data per command. Digital Solid State Pulse Output (KYZ) Modules areuser programmed to reflect VAR-hours, WATT-hours, or VA-hours. See the Modbus CommunicatingI/O Modules User Manual for details on programming the module.


The Modbus Map for the KYZ Pulse Output Module (and operating details) can be found in theModbus Communicating I/O Modules Manual.

NC = Normally Closed; NO = Normally Open; C = Common.


Voltage Rating Up to 300VdcCommands Accepted Read and Write with at least 4 registers of data per command





The device will operate with the following Default Mode Parameters. See section 10.4.1 for details.Address 247 (F7H)Baud Rate 57600 BaudTransmit Delay Time 20 csec

10.8.3: Normal Mode

Energy readings are given to the device frequently. The device generates a pulse at each channelafter a certain energy increase.

Normal Operation consists of three processes:

1. The first process accepts writes to registers 04097 - 04112. Writes can be up to four registers long and should end on the fourth register of a group (register 04100, or registers 04103-04112 or registers 04109-04112). These writes can be interpreted as two-byte, four-byte, six-byte or eight-byte energy readings. The reception of the first value for a given channel provides theinitial value for that channel. Subsequent writes will increment the Residual for that channel by the difference of the old value and the new value. The previous value is then replaced with the new value. Attempting to write a value greater than the programmed Rollover Value for a given channel is completely ignored and no registers are modified. If the difference is greater than halfof the programmed Rollover Value for a given channel, the write does not increment the Residualbut does update the Last Value. Overflow of the Residual is not prevented.

2. The second process occurs in the main loop and attempts to decrement the Residual by the Programmed Energy/Pulse Value. If the Residual is greater than the Programmed Energy/Pulse Value and the Pending Pulses Value for that channel is not maxed, then Residual is decremented appropriately and the Pending Pulses is incremented by two, signifying two more transitions and one more pulse.

3. The third process runs from a timer which counts off pulse widths from the Programmable Minimum Pulse Width Values. If there are Pulses Pending for a channel and the delay has passed, then the Pulses Pending is decremented for that channel and the Output Relay is toggled.

Operation Indicator (0000H = OK, 1000H = Problem):Bit 1: 1 = EEPROM FailureBit 2: 1 = Checksum for Communications Settings badBit 3: 1 = Checksum for Programmable Settings badBit 4: 1 = 1 or mor Communications Settings are invalidBit 5: 1 = 1 or more Programmable Settings are invalidBit 6: 1 = 1 or more Programmable Settings have been modifiedBit 7: 1 = Forced Default by Reset Value

Bit 15: 1 = Normal Operation of the device is disabled


10.9.1: Overview

The Digital Status Input Module is used for either additional status detect or for accumulating pulsesfrom external equipment, such as power meters, water meters, etc.




The device will operate with the following Default Mode Parameters. See section 10.4.1 for details.Address 247 (F7H)Baud Rate 57600 BaudTransmit Delay Time 20 csec

10.9: Digital Status Input Module

Digital Status Input Module Specifications

Model Number

Communication

Power Requirement


Voltage Rating

Detection

Factory Settings


8DI1

RS-485, Modbus RTU




(-20 to 79)°C / (-4 to +158)°FUp to 300Vdc

Wet/Dry, Auto Detect

Modbus Address: 164

Baud Rate: 57600


Modbus Address: 247

Baud Rate: 57600

256 byte I2C EEPROM for storage of ProgrammableSettings and Nonvolatile Memory

Memory



10.9.3: Normal Mode

The device is polling the inputs at 100Hz (once every 10 msec), debouncing the inputs and incrementing the Transition Accumulators for each channel as appropriate.

The inputs are represented by Channel 1 in the LSB through Channel 8 in the MSB of the low orderbyte of the register.

The Modbus Map for the Digital Status Input Modules (and operating details) can be found in theModbus Communicating I/O Modules Manual.

10.10: Specifications

The following multiple analog or digital I/O modules mount externally to the Nexus Socket Meter.The Nexus 1262 and 1272 Units DO NOT SUPPORT I/O MODULES. Use an additional powersupply, such as PSIO, to provide I/O capability. See Chapter 6 for mounting diagrams.

Analog Transducer Signal Outputs (Up to two modules can be used with the Nexus.)1mAON4: 4 Analog Outputs, scalable, bidirectional.1mAON8: 8 Analog Outputs, scalable, bidirectional.20mAON4: 4 Analog Outputs, scalable.20mAON8: 8 Analog Outputs, scalable.

Analog Transducer Inputs (Multiple modules can be used.)8AI1: 8 Analog Inputs 0–1mA, scalable and bidirectional.8AI2: 8 Analog Inputs 0–20mA, scalable and bidirectional.8AI3: 8 Analog Inputs 0–5Vdc, scalable and bidirectional.8AI4: 8 Analog Inputs 0–10Vdc, scalable and bidirectional.

Digital Dry Contact Relay Outputs (Multiple modules can be used.)4RO1: 4 Relay Outputs 10 Amps, 125Vac, 30Vdc, Form C.

Digital Solid State Pulse Outputs (Multiple modules can be used.)4PO1: 4 Solid State Pulse Outputs, Form A KYZ pulses.

Digital Inputs (Multiple modules can be used.)8DI1: 8 Digital status inputs Wet/Dry Auto Detect, up to 300Vdc.

Other I/O AccessoriesPSIO: External Power Supply which is necessary if you are connecting I/O modules to a Nexus

1262 or 1272 Socket Meter.MBIO: Bracket for surface-mounting I/O modules to any enclosure.


11.1: Wiring Diagrams

Choose from four supported meter forms based on the rated voltage and hookup required for your application. Corresponding wiring diagrams appear on the following pages. If the connection diagramyou need is not listed, contact EIG for a custom connection diagram. Form 9S mounted in an A/SAdapter is shown in Figure 11.11.

NOTE: Form 45S replaces Form 5S and may also be used in 4-wire circuits.

Fig # Description

11.2

11.4

Form 9S 4-Wire Delta, no PTs, 3 CTs

Form 36S 4-Wire Wye, 2 PTs, 3 CTs

11.5 Form 39S 4-Wire Wye, no PTs, 4 CTs

11.6 Form 39S 4-Wire Wye, 3 PTs, 4 CTs

11.1

Form 9S 4-Wire Wye, 3 PTs, 3 CTs

Form 9S 4-Wire Wye, no PTs, 3 CTs

11.3

Nexus 1262/1272 Forms

11.7 Form 45S 4-Wire Wye, 2 PTs, 3 CTs

11.8 Form 45S 4-Wire Wye, no PTs, 3 CTs

Chapter 11Electrical Installation for Nexus 1262/1272

Table 11.1: Nexus 1262/1272 Forms

GROUNDING: Industrial meters are typically grounded at the service entrance (not the meter) per NEC (1999) Section 250-24(5) and 250-26.

AUXILIARY POWER: Meters may be externally powered using a (120 to 230)Vac or(125 to 400)Vdc power supply.

NOTE: For forms not on the above list, contact the factory and let us know your requirements.

11.9

11.10 Form 45S 3-Wire Delta, 2 PTs, 2 CTs

Form 45S 3-Wire Delta, no PTs, 2 CTs

11.11 Form 9S mounted in S/A Adapter


Fig 11.1: Form 9S 4-Wire Wye, no PTs, 3 CTs


Fig 11.2: Form 9S 4-Wire Delta, no PTs, 3 CTs

Fig 11.3: Form 9S 4-Wire Wye, 3 PTs, 3 CTs


Fig 11.9: Form 45S 3-Wire Delta, no PTs, 2 CTs


Fig 11.10: Form 45S 3-Wire Delta, 2 PTs, 2 CTs


11.2: 9S Meter Mounted in S/A Adapter

Any of the 9S Forms can be mounted in an S/A Adapter, such as the one shown below. The socket meter is “pushed” into the S/A Adapter until the meter “snaps” into place. The blades on the back of the socket meter make the proper connection. See Figures 11.1 to 11.3 for the 9S wiring diagrams.

Fig 11.11: Form 9S mounted in an S/A Adapter (Front removed)



Chapter 12Nexus 1262/1272 Switchboard Meter

12.1: Introduction

This chapter gives you a brief overview of the Nexus 1262/1272 Switchboard Option. The NexusSwitchboard Meter gives you all the features of the Nexus Socket Meter in a compact case. Easyinstallation or disconnection is the primary benefit of choosing this option. The Switchboard Systemlets you install or “rack out” the meter in two easy steps. Minimal manual wiring is required to con-nect or disconnect the meter.

The Nexus Switchboard Meter works just like the Nexus 1262/1272 Meter. For a complete summary of all the features, see Chapter 2 of this manual. For details on any of the many features,see the Table of Contents for the desired feature.

The differences are few: The label on the face of the meter will be the same but the label on theshroud may be slightly different, depending on options selected (see section 12.2 for label details);dimensions are obviously different (see section 12.3); installation is different and easy (see section12.4) and wiring is different (see section 12.5).

Caution: Power In on 1262/1272 units is configured differently. Please check wiring carefully.

Fig. 12.1: 1262/1272 Switchboard Meter, Front View


12.2: Labels

The label on the face of the meter will be the same as the Nexus 1262/1272 Socket Meter but thelabel on the shroud may have some additional items, depending on options selected. See Chapter 3of this manual for a description of the components on both labels and the available options for theOptions Label.

Fig. 12.2: Front view of the 1272 Switchboard Meter

Fig. 12.3: Options Label for the 1262/1272 Switchboard Meter


12.3: Specifications and Dimensions

The Nexus 1262/1272 Switchboard Meter specifications are the same as for the Nexus 1262/1272Socket Meter, except for the following:

The dimensions are detailed below.Maximum Voltage for the Switchboard Meter ONLY is 120 Volts RMS.

The specifications are detailed in Chapter 2 of this manual.

The Nexus Switchboard Meter is essentially the socket meter in an optional oblong case. Thedimensions are detailed in Figures 12.1 (Front View), 12.4 (Back View) and 12.5 (Side View).

Caution: Power In on new units is configured differently. Please check wiring carefully.

Fig. 12.4: Switchboard Meter, Back View

Electro Industries/GaugeTechwww.electroind.com


Fig. 12.5: Switchboard Meter, Side View


12.4: Installation

The Nexus Switchboard Meter provides two-step installation or disconnection.

1. Insert the case into a prepared mounting hole for the switchboard case. Secure with mounting screws. Before installing the meter, check the battery connections (sections 6.2, 5.4.4).

2. Slide the meter into the case and secure by sliding the chassis levers until they snap into place. Connectors for the following are located on the back of the meter. The connectors will automatically plug into the available connectors on the mounting board (see figure below).

Pulse Outputs - Four ChannelsStatus InputsPhoneLine/NetworkPower InCOM4 - COM1 - IRIG-B (1272 Only)Modem Gateway RS-485

Position the case front against the four screw holes. Secure the front of the case by turning the fourbuilt-in screws in each of the corners.

Fig. 12.6: Front Case showing Built-In Screws

Built-inScrews


12.5: Wiring Diagrams

The wiring of the Nexus 1262/1272 Switchboard Meter is similar to that of the Nexus Socket Meter.The forms available for this meter are detailed in Table 12.1 below.

The meter snaps into place and is secured with levers and screws. All input and output connectionsare made automatically as the meter is installed. Note the view of the meter case in Fig. 12.7 below.Wiring options are detailed in Figures 12.8 through 12.12. For special requirements, contact ourservice department. All wiring should be done by a licensed professional. Actual installation procedures, materials, equipment and connections must conform to applicable codes and standards.

Fig. 12.7: Back Angle View of Switchboard Meter

Figure # Description

12.8 Form 9Z 4-Wire Wye, no PTs, 3 CTs

12.9 Form 9Z 4-Wire Delta, no PTs, 3 CTs

Table 12.1: Switchboard Meter Forms

12.10 Form 9Z 4-Wire Wye, 3 PTs, 3 CTs

12.11 Form 45Z 3-Wire Delta, no PTs, 2 CTs

12.12 Form 45Z 3-Wire Delta with 2 PTs, 2 CTs

1262/1272 Switchboard Meter Forms


Fig. 12.8: 9Z Transformer Rated 4-Wire Wye form with no PTs, 3 CTs.

Caution: Power In on new unitsis configured differently.

Please check wiring carefully.


Fig. 12.9: 9Z Transformer Rated 4-Wire Delta form with no PTs, 3 CTs.

Caution: Power In on new units is configured differently.



Fig. 12.10: 9Z Transformer Rated 4-Wire Wye form with 3 PTs, 3 CTs.




Fig. 12.11: 45Z Transformer Rated 3-Wire Delta form with no PTs, 2 CTs.




Fig. 12.12: 45Z Transformer Rated 3-Wire Delta form with 2 PTs, 2 CTs.




Chapter 13Nexus Calculations

13.1: Measurements and Calculations

The Nexus 1262/1272 Socket Meter measures many different power parameters. The following is a listof the formulas used to conduct calculations with samples for Wye and Delta services.

Samples for Wye: van , vbn , vcn , ia , ib , ic , in Samples for Delta: vab , vbc , vca , ia , ib , ic

Root Mean Square (RMS) of Phase to Neutral Voltages: n = number of samples.

For Wye: x = an, bn, cn

Root Mean Square (RMS) of Currents: n = number of samples

For Wye: x = a, b, c, nFor Delta: x = a, b, c

Root Mean Square (RMS) of Phase to Phase Voltages: n = number of samples

For Wye: x,y = an, bn or bn, cn or cn, an

2( )

1X

n

x tt

RMS

v

nV ==∑

2( )

1X

n

x tt

RMS

i

nI ==∑

( )2( ) ( )1

XY

n

x t y tt

RMS

v v

nI =

−=∑


For Delta: xy = ab, bc, ca

Power (Watts) per phase:

For Wye: x = a, b, c

Apparent Power (VA) per phase:

For Wye: X = A, B, C

Reactive Power (VAR) per phase:


Q per phase:


For Delta: unused

XXN RMSX RMSVA V I= •

( ) ( )1

n

xn t x tt

x

v i

nW =

•=∑

2( )

1XY

n

xy tt

RMS

v

nV ==∑

2 2

X X XVAR VA W= −

32

X XX

VAR WQ +=


Power (Watts) Total:

For Wye:

For Delta:

Reactive Power (VAR) Total:

For Wye:

For Delta:

Apparent Power (VA) Total:

For Wye:

For Delta:

T A B CW W W W= + +

( ) ( ) ( ) ( )1

( )n

ab t a t bc t c tt

T

v i v i

nW =

• − •=∑

T A B CVAR VAR VAR VAR= + +

( )2

( ) ( )21

AAB

n

ab t a tt

RMST RMS

v i

nVAR V I =

⎛ ⎞•⎜ ⎟⎜ ⎟= • −⎜ ⎟⎜ ⎟⎝ ⎠

∑

( )2

( ) ( )21

CBC

n

bc t c tt

RMSRMS

v

n

iV I =

⎛ ⎞•⎜ ⎟⎜ ⎟• −⎜ ⎟⎜ ⎟⎝ ⎠

∑

+

2 2

T T TVA W VAR= +

T A B CVA VA VA VA= + +


Total Q:

For Wye:

For Delta:

Total Energy:

X = WT, VART, VAT, QT

Power Factor (PF):

For Wye: X = A, B, C, TFor Delta: X = T

Total Average Power Factor:

X = Quadrants 1 & 4 (positive Wh), Quadrants 2 & 3 (negative Wh)

XX

X

WPF VA=

_ X

XTotal Ave

X

WhPFVAh

=

3600X

Xh = ∑

T A B CQ Q Q Q= + +

23 TT

T

WVARQ =+


Phase Angles:X = A, B, C

% Total Harmonic Distortion (%THD):

For Wye: X = VAN, VBN, VCN, IA, IB, ICFor Delta: X = IA, IB, IC, VAB, VBC, VCA

K Factor:

X = IA, IB, IC

Voltage Imbalance:

Current Imbalance:

( )( )

127 2

1127 2

1

h

h

Xh

X

Xh

h RMSKFactor

RMS=

=

=∑

∑

( )1

127 2

2hX

hX

X

RMSTHD RMS

==∑

( )2

VImbAN BN CN

an bn cn

V V V

nn

v v v

RMS RMS RMS

+ +

=+ +

∑

IImb CalcN

A B C

I

I I I

RMSRMS RMS RMS

=+ +

( )1cosX XPF−=∠


13.2: Demand Integrators

Power utilities take into account both energy consumption and peak demand when billing customers.Peak demand, expressed in kilowatts (kW), is the highest level of demand recorded during a set periodof time, called the interval. The Nexus 1262/1272 supports the following most popular conventions foraveraging demand and peak demand: Thermal Demand, Block Window Demand, Rolling WindowDemand and Predictive Window Demand. You may program and access all conventions concurrentlywith the Nexus Communicator software (see the Nexus Communicator User Manual).

Thermal Demand: Traditional analog watt-hour (WH) meters use heat-sensitive elements to measure temperature rises produced by an increase in current flowing through the meter. A pointermoves in proportion to the temperature change, providing a record of demand. The pointer remainsat peak level until a subsequent increase in demand moves it again, or until it is manually reset. TheNexus mimics traditional meters to provide Thermal Demand readings.

Each second, as a new power level is computed, a recurrence relation formula is applied. This formula recomputes the thermal demand by averaging a small portion of the new power value with a large portion of the previous thermal demand value. The proportioning of new to previous isprogrammable, set by an averaging interval. The averaging interval represents a 90% change in thermal demand to a step change in power.

Block (Fixed) Window Demand: Fixed Window Demand produces an average (arithmetic mean) ofpower readings over a programmed interval.

Example: A typical setting of 15 minutes produces an average value every 15 minutes (at 12:00,12:15, 12:30, etc.) for power readings over the previous fifteen minute interval (11:45-12:00, 12:00-12:15, 12:15-12:30, etc.)

Rolling (Sliding) Window Demand: Rolling Window Demand functions like multiple, overlappingBlock Window Demands. The programmable settings provided are the number and length ofdemand subintervals. Every subinterval, an average (arithmetic mean) of power readings over thesubinterval is internally calculated. This new subinterval average is then averaged (arithmetic mean)with as many previous subinterval averages as programmed, to produce the Rolling WindowDemand.

Example: With settings of 3 five minute subintervals, subinterval averages are computed every 5minutes (12:00, 12:05, 12:10, 12:15. etc.) for power readings over the previous five minute interval(11:55-12:00, 12:00-12:05, 12:05-12:10, 12:10-12:15, etc.). Further, every 5 minutes, the subintervalaverages are averaged in groups of 3 (12:00, 12:05, 12:10; 12:05, 12:10, 12:15. etc.) to produce a fifteen (5*3) minute average every 5 minutes (rolling (sliding) every 5 minutes) (11:55-12:10, 12:-12:15, etc.).

Predictive Window Demand: Predictive Window Demand expands on the above Rolling WindowDemand. Rolling Window Demand waits until the end of a subinterval to update the demand.Predictive Window Demand uses the average of the previously completed subinterval, weighted by aprogrammable factor, to guess at the average of the upcoming subinteval During the nextsubinterval, as actual power readings occur, the value for the subinterval consists of the portionactually mesured plus a predicted guess, prorated to the subinterval time remaining.


Example: Using the previous settings of 3 five minute intervals, and a new setting of 120%prediction factor, the working of the Predictive Window Demand could be described as follows:At 12:10, we have the average of the subintervals from 11:55-12:00, 12:00-12:05 and 12:05-12:10.In five minutes, we will have an average of the subintervals 12:00-12:05 and 12:05-12:10 (which weknow) and 12:10-12:15, which we do not yet know. As a guess, we will use the last subinterval(12:05-12:10), as an approximation for the next subinterval (12:10-12:15). As a further refinement,we will assume that the next subinterval might have a higher average (120%) than the lastsubinterval. As we progress into the subinterval, (for example, up to 12:11), the Predictive WindowDemand will be the average of the first two subintervals (12:00-12:05, 12:05-12:10), the actualvalues of the current subinterval (12:10-12:11) and the prediction for the remainder of thesubinterval, 4/5 of 120% of the 12:05-12:10 subinterval.

# of Subintervals = nSubinterval Length = LenPartial Subinterval Length = CntPrediction Factor = Pct

PartialSubn ... Sub1 Sub0 Predict

Len Len Len Cnt Len

1

0

Len

ii

ValueSub

Len

−

==∑

1

0

Cnt

ii

ValuePartial

Cnt

−

==∑

2

0 1

n

ii

ValueLen CntPartial xPct

n Len

−

=

⎡ ⎤⎢ ⎥ ⎡ ⎤⎡ ⎤−⎡ ⎤⎢ ⎥+ + −⎢ ⎥⎢ ⎥⎢ ⎥⎣ ⎦⎢ ⎥ ⎣ ⎦⎣ ⎦⎢ ⎥⎣ ⎦

∑

2

0 0 1

1 2 ( 1)

n

ii n

SubSub Sub Len Cntx xPct

n x n Len

−

= −

⎡ ⎤⎢ ⎥ ⎡ ⎤− −⎡ ⎤⎢ ⎥+ + ⎢ ⎥⎢ ⎥− − ⎣ ⎦⎢ ⎥ ⎣ ⎦⎢ ⎥⎣ ⎦

∑

Electro Industries/GaugeTech Doc #: E151-7-01 V1.01 13-8

Chapter 14EN 50160 Flicker

14.1: Overview

Flicker is the sensation that is experienced by the human visual system when it is subjected tochanges occurring in the illumination intensity of light sources. The primary effects of flicker areheadaches, irritability and sometimes epilepsy.

IEC 61000-4-15 and former IEC 868 describe the methods used to determine flicker severity. Thisphenomenon is strictly related to the sensitivity and the reaction of individuals. It can only be studied on a statistical basis by setting up suitable experiments among people.

14.2: Theory of Operation

Flicker can be caused by voltage variations which are caused by variable loads, such as arc furnaces,laser printers and microwave ovens. In order to model the eye brain change, which is a complex physiological process, the signal from the power network has to be processed while conforming withFigure 16.1 below.

• Block 1 consists of scaling circuitry and an automatic gain control function that normalizes inputvoltages to Blocks 2, 3 and 4. For the specified 50 Hz operation, the voltage standard is 230 VRMS.

• Block 2 recovers the voltage fluctuation by squaring the input voltage scaled to the referencelevel. This simulates the behavior of a lamp.

• Block 3 is composed of a cascade of two filters and a measuring range selector. In this implementation, a log classifier covers the full scale in use so the gain selection is automatic andnot shown here. The first filter eliminates the DC component and the double mains frequencycomponents of the demodulated output.

The configuration consists of a .05 Hz Low High Pass filter and a 6 Pole Butterworth Low Passfilter located at 35 Hz. The second filter is a weighting filter that simulates the response of thehuman visual system to sinusoidal voltage fluctuations of a coiled filament, gas-filled lamp (60W - 230 V). The filter implementation of this function is as specified in IEC 61000-4-15.

• Block 4 is composed of a squaring multiplier and a Low Pass filter. The Human FlickerSensation via lamp, eye and brain is simulated by the combined non-linear response of Blocks 2,3 and 4.

• Block 5 performs an online statistical cumulative probability analysis of the flicker level. Block5 allows direct calculation of the evaluation parameters Pst and Plt.

Flicker Evaluation occurs in the following forms: Instantaneous, Short Term or Long Term. Eachform is detailed below:


• Instantaneous Flicker EvaluationAn output of 1.00 from Block 4 corresponds to the Reference Human Flicker PerceptibilityThreshold for 50% of the population. This value is measured in Perceptibility Units (PU) and islabeled Pinst. This ia a real time value and it is continuously updated.

• Short Term Flicker EvaluationAn output of 1.00 from Block 5 (corresponding to the Pst value) corresponds to the conventionalthreshold of irritability per IEC 1000-3-3. In order to evaluate flicker severity, two parametershave been defined: one for the short term called Pst (defined in this section) and one for the longterm called Plt (defined in the next section).

The standard measurement time for Pst is 10 minutes. Pst is derived from the time at level statistics obtained from the level classifier in Block 5 of the flicker meter. The following formula is used:

Where the percentiles P(0.1), P(1), P(3), P(10), P(50) are the flicker levels exceeded for 0.1, 1, 2,20 and 50% of the time during the observation period. The suffix S in the formula indicates thatthe smoothed value should be used. The smoothed values are obtained using the following formulas:

P(1s) = (P(.7) + P(1) + P(1.5))/3P(3s) = (P(2.2) + P(3) + P(4))/3P(10s) = (P(6) + P(8) + P(10) + P(13) + P(17))/5P(50s) = (P(30) + P(50) + P(80))/3

The .3-second memory time constant in the flicker meter ensures that P(0.1) cannot changeabruptly and no smoothing is needed for this percentile.

• Long Term Flicker EvaluationThe 10-minute period on which the short-term flicker severity is based is suitable for short dutycycle disturbances. For flicker sources with long and variable duty cycles (e.g. arc furnaces) it isnecessary to provide criteria for long-term assessment. For this purpose, the long-term Plt isderived from the short-term values over an appropriate period. By definition, this is 12 short-term values of 10 minutes each over a period of 2 hours. The following formula is used:

Where Psti (i = 1, 2, 3, ...) are consecutive readings of the short-term severity Pst.

SummaryFlicker = Changes in the illumination of light sources due to cyclical voltage variations.Pinst = Instantaneous flicker values in Perceptibility Units (PU).Pst = Value based on 10-minute analysis.Plt = Value based on 12 Pst values.


ssssst PPPPPP 5010311.0 08.028.00657.00525.00314.0 ++++=

3 1

3

N

PP

N

isti

lt

∑==

Measurement Procedure1. Original Signal with amplitude variations.2. Square demodulator.3. Weighted filter.4. Low pass filter 1

storder.

5. Statistical computing.

Data available

Pst, Pst Max, Pst Min values for long term recordingPlt, Plt Max, Plt Min values for long term recording

Figure 14.1: Simulation of Eye Brain Response

14.3: Setup

Initially the user must set up several parameters to properly configure Flicker. Using CommunicatorEXT, from the Icon Menu select Edit Device Profile. From the Device Profile, select Power Qualityand Alarm Settings, EN 50160 Flicker. The following screen will appear:


Block 1 Block 2 Block 3

VoltageDetectorand GainControl

InputVoltageAdaptor

SquareLaw

Demodulator

High PassFilter(DC

Removal)

LowPass Filter

(CarrierRemoval

WeightingFilter

SquaringMultiplier

1stOrderSlidingMeanFilter

A/DConverterSampling

Rate>50Hz

Minimum64 level

Classifier

OutputInterface

Programming of short andlong observation periods

Block 4 Block 5

Simulation Of Eye Brain Response

Output RecordingInstantaneous Flicker in

Perceptibility Units(Pinst)

Output and Data DisplayPst Max/Min PstPlt Max/Min Plt

• Select a Pst time range from 1 to 10 minutes. The standard measurement period is nominally 10minutes.

• Select a Plt time range from 1 to 240 minutes. The standard measurement is nominally 12 Pstperiods (120 minutes). Plt time must always be equal to or great than and a multiple of Pst time.This is reflected in the selections available to the user.

• Select the frequency of operation. 50 Hz is the approved frequency according to Flicker standards. A 60 Hz implementation is available and can be selected. This implementation is theproposed 60 Hz standard that is still in the approval process.

Remember the voltage is normalized. For 50 Hz, the normalized voltage is 230 V and for 60 Hz,the normalized voltage is 120 V.

Press OK when you are finished.

Press Help for more information on this topic.

14.4: Software - User Interface

Main screenFrom the Communicator EXT Icon Menu select Real Time Poll, Flicker. The following screenappears:

This section describes the Main Screen functions. The available values (Instantaneous, Short Term,Long Term) will be described below.


TimeStart/Reset is the time when Flicker was started or reset. A Reset of Flicker causes the Max/Min

values to be cleared and restarts the Flicker Pst and Plt timers. A Start of Flicker is also equivalent to a Reset in that the PST and PLT are restarted and the Max/Min Values are cleared.

Stop corresponds to the time when Flicker is turned off.Current is the current clock time.Next Pst is the countdown time to when the next Pst value is available.Next Plt is the countdown time to when the next Plt value is available.

StatusIndicates the current status. Active = On. Stopped = Off.

FrequencyBase is the current operating frequency selected by the user (50 or 60 Hz).Current is the real time frequency measurement of the applied voltage.Base Voltage is the normalized voltage for the selected frequency (230 V for 50 Hz or 120 V for

60 Hz).

Flicker MonitoringClicking on Stop causes Flicker to stop being processed and freezes all the current values. Stop

Time is recorded and clears the current Max/Min ValuesClicking on Start starts Flicker processing. Start Time is recorded.Clicking on Reset causes the Max/Min values to be cleared and restarts the Flicker Pst and Plt

timers.Click OK to exit the Flicker screen.Click Help for more information on this topic.

Instantaneous ReadingsRefer to the Instantaneous section of the Main screen above. If you are on the Short or Long Termscreens, click on the Instantaneous tab to display the Instantaneous screen. The PU values, Pinst forVoltage Inputs Va, Vb and Vc are displayed here and are continuously updated. The correspondingCurrent Voltage values for each channel are displayed for reference.


Short Term ReadingsClick on the Short Term tab to access the screen containing three groups of Pst readings.

Pst Readings Displayed• Current Pst values for Va, Vb and Vc and the time of computation.• Current Pst Max values for Va, Vb and Vc since the last reset and the time of the last reset.• Current Pst Min values for Va, Vb and Vc since the last reset and the time of the last reset.

The following screen is displayed:

Long Term ReadingsClick on the Long Term tab to access the Plt readings. The screen below displays three groups ofPlt values.

Plt Readings Displayed• Current Plt values for Va, Vb and Vc and the time of computation.• Current Plt Max values for Va, Vb and Vc since the last reset and the time of the last reset.• Current Plt Min values for Va, Vb and Vc since the last reset and the time of the last reset.


14.5: Logging

The Nexus is capable of logging Flicker values in an independent log. When Flicker is on, entriesare made into the log in accordance with the times that associated values occur. Pst, Pst Max, PstMin, Plt, Plt Max, Plt Min, Start/Reset and Stop times are all recorded. All values can be down-loaded to the Log Viewer where they are available for graphing or export to another program, suchas Excel. All Flicker values are predefined and cannot be changed.

14.6: Polling

The Pinst, Pst, Pst Max, Pst Min, Plt, Plt Max, Plt Min values are all capable of being polledthrough the Communications Port. Refer to the Nexus Modbus and DNP Mappings for registerassignments and data definitions.

14.7: Log Viewer

From the Communicator EXT Log Viewer screen, using the menus at the top of the Log Viewerscreen, select a meter, time ranges and values to access. Select Flicker.

The values and the associated time stamps (when the values occurred) are displayed in a grid box.Use the buttons at the bottom of the screen to create a graph or export the data to another program.Max and Min values are only displayed; they cannot be graphed. But, Max and Min values areavailable for export.

Graphed values include Pst and Plt Va, Vb and Vc.Displayed values include Pst and Plt Max and Min for Va, Vb and Vc.


14.8: Performance Notes

Pst and Plt average time are synchronized to the clock (e.g. for a 10 minute average, the times willoccur at 0, 10, 20, etc.). The actual time of the first average can be less than the selected period toallow for initial clock synchronization.

If the wrong frequency is chosen (e.g. 50Hz selection for a system operating at 60Hz), Flicker willstill operate but the values computed will not be valid. Select carefully.

User settings are stored. If Flicker is on and power is removed from the meter, Flicker will still beon when power returns. This can cause data gaps in the logged data.

The Max and Min values are stored and are not lost if the unit is powered down.

Flicker meets the requirements of IEC 61000-4-15 and former IEC 868. Refer to those specifications for more details, if needed.

Operation is at 230V for 50Hz and 120V for 60Hz as per specification. If the input voltage is different, the system will normalize it to 230V or 120V for computational purposes.


Electro Industries/GaugeTech Doc # E151-7-01 V1.01 A-1

Appendix ATransformer Loss Compensation Excel Spreadsheet

with Examples

A.1: Calculating Values

Transformer Loss Compensation is discussed in Chapter 8 of this manual. Values for three elementinstallations can be calculated in two ways:

• Click the TLC Calculator button on the Transformer Loss screen of the Nexus Device Profile. The TLC Calculator button activates an Excel Spreadsheet, ONLY if you have MS Excel installed on your computer. A copy of the Excel Spreadsheet is offered on the following pages with example numbers.

1. Enter the required data into the Excel Spreadsheet. The Excel program will calculate the values needed for the Transformer Loss screen of the Device Profile.

2. Enter the values into the Device Profile.

• Use the worksheet found in Chapter 9, “Three Element Loss Compensation Worksheet” to calculate the values by hand. Notes under each section will assist you.

1. Enter values based on the tranformer manufacturer’s test report. The worksheet is progressive and notes under each section will guide you to the next section.

2. Enter the values into the Device Profile.

A.2: Excel Spreadsheet with Example Numbers

If you have MS Excel installed in your computer, use the TLC Calculator button on the TransformerLoss screen of the Device Profile. The copy of the Spreadsheet with Example Numbers found on thefollowing pages will assist you.


Electro Industries / GaugetechWestbury, NY (877) EIMETER [877-346-3837]

Nexus Transformer Loss Compensation CalculationThree Element Meter with 3 Wye-connected PT's and 3 CT's

Company: Substation:

Name: Stn Trf Bank No.:

Date:

Trf Manf:

Trf S/N:

Loss Factors

for Nx Communicator Software Calc Used

% No-Load Loss Watts %LWFE #DIV/0! #DIV/0!

% No-Load Loss VARs %LVFE #DIV/0! #DIV/0!

% Full-Load Loss Watts %LWCU #DIV/0! #DIV/0!

% Full-Load Loss VARs %LVCU #DIV/0! #DIV/0!

Winding Voltage Connection

HV - High

XV - Low

YV - Tert.

Transformer Test Data

Value 3 Phase 1 Phase Calculated Calc kVA

No Load Loss Watts 0.00 0.00

Full Load Loss Watts 0.00 0.00

% Exciting Current

% Impedance

3 Phase 1 Phase Calculated

Self-Cooled kVA Rating 0

Phase-to-Phase Phase-to-Grd

Test Voltage 0

Full Load Current #DIV/0!

Meter / Installation Data


Potential Trf 0

Current Trf 0

Power Multiplier 0

Meter Secondary Voltage 120 120 volts for Nexus

Meter Secondary Current 5 5 amps for Nexus

Publishing and duplicating rights are property of Electro Industries/Gaugetech.This spreadsheet is designed only to be used with EIG Nexus based metering equipment.

Loss Factors

Watts Loss

MVA Ratings


Electro Industries / GaugeTechWestbury, NY (877) EIMETER [877-346-3837]

Nexus Transformer Loss Compensation Calculation - ExampleThree Element Meter with 3 Wye-connected PT's and 3 CT's



Date:

Trf Manf:

Trf S/N:

Loss Factors


% No-Load Loss Watts %LWFE 0.04314 0.043

% No-Load Loss VARs %LVFE 0.06765 0.068

% Full-Load Loss Watts %LWCU 0.87524 0.875

% Full-Load Loss VARs %LVCU 20.76262 20.763

Winding Voltage Connection

HV - High 138000 delta

XV - Low 13090 wye

YV - Tert.

Transformer Test Data

Value 3 Phase 1 Phase Calculated Calc kVA

No Load Loss Watts 15400 5133.33 5.13

Full Load Loss Watts 69200 23066.67 23.07

% Exciting Current 0.183

% Impedance 9.78

3 Phase 1 Phase Calculated

Self-Cooled kVA Rating 16800 5600


Test Voltage 13090 7558

Full Load Current 741



Potential Trf 7200 120 60

Current Trf 1500 5 300

Power Multiplier 18000




ABB

AT4391-01

Loss Factors

Watts Loss

MVA Ratings

16.8/22.4/28.0

ABC Power Company

Joe Engineer

2/14/2002

Big Station

131


Electro Industries / GaugetechWestbury, NY (877) EIMETER [877-346-3837]

Nexus Line Loss Compensation CalculationThree Element Meter with 3 Wye-connected PT's and 3 CT's



Date:

Metering Point Information

Loss Factors


% Full-Load Loss Watts %LWCU #DIV/0! #DIV/0!

% Full-Load Loss VARs %LVCU #DIV/0! #DIV/0!

Transmission Line Impedance Data

Quantity PU Value % Value Used

R 0

X 0

MVA Base 0

e Nominal Voltage



Potential Trf 0

Current Trf 0

Power Multiplier 0



Value 3 Ph Loss 1 Ph Watt 1 Ph kW

Full Load Loss Watts - 0.00 0.00

Full Load Loss VARs - 0.00 0.00

Watts Loss at CT Full Load #DIV/0!


Test Voltage 0 0

Full Load Current #DIV/0!


Loss Factors


Electro Industries / GaugeTechWestbury, NY (877) EIMETER [877-346-3837]

Nexus Line Loss Compensation Calculation - ExampleThree Element Meter with 3 Wye-connected PT's and 3 CT's



Date:

Metering Point Information

Loss Factors


% Full-Load Loss Watts %LWCU 0.00362 0.004

% Full-Load Loss VARs %LVCU 0.01872 0.019

Transmission Line Impedance Data

Quantity PU Value % Value Used

R 0.0304 0.0304

X 0.1573 0.1573

MVA Base 100 100

e Nominal Voltage 138000



Potential Trf 138000 115 1200

Current Trf 900 5 180

Power Multiplier 216000



Value 3 Ph Loss 1 Ph Watt 1 Ph kW

Full Load Loss Watts 3,040 1013.33 1.01

Full Load Loss VARs 15,730 5243.33 5.24

Watts Loss at CT Full Load 14,068


Test Voltage 138000 79674

Full Load Current 418


Loss Factors

ABC Power Company Big Station

Joe Engineer Small Station 138

2/14/2002

Meter point is 45 miles down line from Big Station.

Electro Industries/GaugeTech Doc # E151-7-01 V1.01 B-1

Appendix BBlade Configuration

for Forms 9S & 36S, 39S and 45S

B.1: 1262/1272 Forms

Four supported forms for the Nexus 1262/1272 Socket Meters with their wiring configurations aredetailed in Chapter 11 of this manual. Those forms are based on the rated voltage and hookuprequired for your application. (Custom forms and configurations are also available from EIG.

The four supported forms for the Nexus 1262/1272 Socket Meters are listed below:

• 9S4-Wire Wye, no PTs, 3CTs4-Wire Delta, no PTs, 3CTs4-Wire Wye, 3 PTs, 3 CTs

• 36S4-Wire Wye, 2 PTs, 3 CTs

• 39S4-Wire Wye, no PTs, 4 CTs4-Wire Wye, 3 PTs, 4 CTs

• 45S4-Wire Wye, 2 PTs, 3 CTs4-Wire Wye, no PTs, 3 CTs3-Wire Delta, no PTs, 2 CTs3-Wire Delta, 2 PTs, 2 CTs

B.2: Blade Configuration Drawings

Detail drawings of the Blade Configurations are offered on the following pages. There are threeconfigurations because the 9S and the 36S are the same. There is a drawing showing the knockoutholes for each configuration.

Note: The forms referred to in this chapter comply with ANSI forms 9S, 36S, 39S and 45S.


Fig. B.1: Form 9S & 36S Base with Knock Out Holes

Fig. B.2: Form 39S Base with Knock Out Holes

Note: The forms referred to on this page comply with ANSI forms 9S, 36S and 39S.


Fig. B.3: Form 45S Base with Knock Out Holes

Note: The form referred to on this page complies with ANSI form 45S.

Electro Industries/GaugeTech Doc # E151-7-01 V1.01 C-1

Appendix CTFTP Server Program Setup

C.1: TFTP Setup

A free shareware TFTP (Trivial File Transfer Protocol) server program known as tftpd32 is provided to customers to be used to update firmware for the INP-100 Ethernet card. The program filesare located on the software installation CD.

NOTE: tftpd32 must be running to update the firmware.

Setup requirements:1. Windows Operating System2. A working Ethernet card with a valid IP Address3. Winzip software (only if Windows OS does not open the zip file automatically)

Setup procedures: 1. In your PC’s hard disk, create a folder with a name.

Example: C:\Program Files\TFTPD32.2. Locate the Zipped tftpd32 program files on the CD. Then, use the Winzip program to extract

all compressed files into the folder you have created in Step 1.3. In your PC’s hard drive, create a folder with a name to be used as the root directory for TFTP

Server. Example: C:\Program Files\TFTPD32\TFTP_files.

4. To start running the program, double click on tftpd32.exe.

Configuring tftpd32:1. Start the TFTPD32 program (Step 4 above). The following screen appears:

Figure C.1: TFTPD32 Program Screen

Electro Industries/GaugeTech Doc # E151-7-01 V1.01 C-2

2. Click the Settings button. The Tftpd32 Settings screen appears.

Figure C.2: TFTPD32 Settings Screen

NOTE: The screen shown here displays EIG’s recommended settings.

NOTE: All firmware files for INP100 should be placed inside the “C:\Program Files\TFTPD32\TFTP_files” folder before updating firmware.

WARNING: It is not recommended to check the “Activate Tftpd32 on this interface” box. Oncethat box is checked and your computer’s IP is changed, the TFTPD32 program may not work properly. To fix the problem, you may have to disable this feature inside the Windows Registry.

Electro Industries/GaugeTech Doc # E151-7-01 V1.01 Appendix D-1

Appendix DThree-PPhase Power Measurement

This introduction to three-phase power and power measurement is intended to provide only a briefoverview of the subject. The professional meter engineer or meter technician should refer to moreadvanced documents such as the EEI Handbook for Electricity Metering and the application standardsfor more in-depth and technical coverage of the subject.

D.1: Three-PPhase System Configurations

Three-phase power is most commonly used in situations where large amounts of power will be used because it is a more effective way to transmit the power and because it provides a smoother delivery of power to the end load. There are two commonly used connections for three-phase power, a wye connection or a delta connection. Each connection has several different manifestations in actual use. When attempting to determine the type of connection in use, it is a good practice to follow the circuit back to the transformer that is serving the circuit. It is often not possible to conclusively determine the correct circuit connection simply by counting the wires in the service or checking voltages. Checking the transformer connection will provide conclusive evidence of the circuit connection and the relationships between the phase voltages and ground.

D.1.1: Wye Connection

The wye connection is so called because when you look at the phase relationships and the windingrelationships between the phases it looks like a wye (Y). Fig. D.1 depicts the winding relationshipsfor a wye-connected service. In a wye service the neutral (or center point of the wye) is typicallygrounded. This leads to common voltages of 208/120 and 480/277 (where the first number representsthe phase-to-phase voltage and the second number represents the phase-to-ground voltage).

The three voltages are separated by 120o electrically. Under balanced load conditions with unitypower factor the currents are also separated by 120o. However, unbalanced loads and other conditions can cause the currents to depart from the ideal 120o separation.

Phase A

Phase B Phase C

Figure 1.1: Three-Phase Wye Winding Figure D.1: Three-Phase Wye Winding


Fig D.2: Phasor diagram showing Three-phase Voltages and Currents

The phasor diagram shows the 120o angular separation between the phase voltages. The phase-to-phase voltage in a balanced three-phase wye system is 1.732 times the phase-to-neutral voltage. The center point of the wye is tied together and is typically grounded. Table D.1 shows the common voltages used in the United States for wye-connected systems.

Table D.1: Common Phase Voltages on Wye Services

Usually a wye-connected service will have four wires; three wires for the phases and one for the neutral. The three-phase wires connect to the three phases (as shown in Fig. D.1). The neutral wire is typically tied to the ground or center point of the wye (refer to Figure D.1).

In many industrial applications the facility will be fed with a four-wire wye service but only three wires will be run to individual loads. The load is then often referred to as a delta-connected load but the service to the facility is still a wye service; it contains four wires if you trace the circuit back to its source (usually a transformer). In this type of connection the phase to ground voltage will be the phase-to-ground voltage indicated in Table D.1, even though a neutral or ground wire is not physically present at the load. The transformer is the best place to determine the circuit connection type because this is a location where the voltage reference to ground can be conclusively identified.

Three-phase voltages and currents are usually represented with a phasor diagram. A phasor diagramfor the typical connected voltages and currents is shown in Figure D.2.

Phase-to-Ground Voltage Phase-to-Phase Voltage

120 volts277 volts

2,400 volts7,200 volts

208 volts480 volts

4,160 volts12,470 volts

7,620 volts 13,200 volts

D.1.2: Delta Connection

Delta connected services may be fed with either three wires or four wires. In a three-phase deltaservice the load windings are connected from phase-to-phase rather than from phase-to-ground.Figure D.3 shows the physical load connections for a delta service.

In this example of a delta service, three wires will transmit the power to the load. In a true delta service, the phase-to-ground voltage will usually not be balanced because the ground is not at the center of the delta.

Fig. D.4 shows the phasor relationships between voltage and current on a three-phase delta circuit.

In many delta services, one corner of the delta is grounded. This means the phase to ground voltage will be zero for one phase and will be full phase-to-phase voltage for the other two phases. This is done for protective purposes.

Another common delta connection is the four-wire, grounded delta used for lighting loads. In thisconnection the center point of one winding is grounded. On a 120/240 volt, four-wire, groundeddelta service the phase-to-ground voltage would be 120 volts on two phases and 208 volts on thethird phase. Figure D.5 shows the phasor diagram for the voltages in a three-phase, four-wire deltasystem.


Phase A Phase B

Phase C

Figure 1.3: Three-Phase Delta Winding Relationship

Vab

Vbc

Vca

Ia

Ib

Ic

Figure 1.4: Phasor diagram showing three-phase voltages, currents delta connected.

Figure D.3: Three-Phase Delta Winding Relationship

Figure D.4: Phasor diagram showing Three-Phase Voltages, Currents, Dela Connected

Fig D.5: Phasor diagram showing Three-phase, Four-wire Delta Connected System

D.1.3: Blondell’s Theorem and Three Phase Measurement

In 1893 an engineer and mathematician named Andre E. Blondell set forth the first scientific basis for poly phase metering. His theorem states:

If energy is supplied to any system of conductors through N wires, the total power in the system isgiven by the algebraic sum of the readings of N wattmeters so arranged that each of the N wires contains one current coil, the corresponding potential coil being connected between that wire andsome common point. If this common point is on one of the N wires, the measurement may be madeby the use of N-1 wattmeters.

The theorem may be stated more simply, in modern language:

In a system of N conductors, N-1 meter elements will measure the power or energy taken providedthat all the potential coils have a common tie to the conductor in which there is no current coil.

Three-phase power measurement is accomplished by measuring the three individual phases andadding them together to obtain the total three phase value. In older analog meters, this measurement was accomplished using up to three separate elements. Each element combined the single-phase voltage and current to produce a torque on the meter disk. All three elements werearranged around the disk so that the disk was subjected to the combined torque of the three elements.As a result the disk would turn at a higher speed and register power supplied by each of the threewires.

According to Blondell's Theorem, it was possible to reduce the number of elements under certainconditions. For example, a three-phase, three-wire delta system could be correctly measured withtwo elements (two potential coils and two current coils) if the potential coils were connectedbetween the three phases with one phase in common.

In a three-phase, four-wire wye system it is necessary to use three elements. Three voltage coils are connected between the three phases and the common neutral conductor. A current coil is required ineach of the three phases.

In modern digital meters, Blondell's Theorem is still applied to obtain proper metering. The difference in modern meters is that the digital meter measures each phase voltage and current andcalculates the single-phase power for each phase. The meter then sums the three phase powers to a


single three-phase reading.

Some digital meters calculate the individual phase power values one phase at a time. This means themeter samples the voltage and current on one phase and calculates a power value. Then it samples thesecond phase and calculates the power for the second phase. Finally, it samples the third phase and calculates that phase power. After sampling all three phases, the meter combines the three readings tocreate the equivalent three-phase power value. Using mathematical averaging techniques, this methodcan derive a quite accurate measurement of three-phase power.

More advanced meters actually sample all three phases of voltage and current simultaneously and calculate the individual phase and three-phase power values. The advantage of simultaneous samplingis the reduction of error introduced due to the difference in time when the samples were taken.

Blondell's Theorem is a derivation that results from Kirchhoff's Law. Kirchhoff's Law states that thesum of the currents into a node is zero. Another way of stating the same thing is that the current into anode (connection point) must equal the current out of the node. The law can be applied to measuringthree-phase loads. Figure D.6 shows a typical connection of a three-phase load applied to a three-phase, four-wire service. Krichhoff's Laws hold that the sum of currents A, B, C and N must equal zeroor that the sum of currents into Node "n" must equal zero.

If we measure the currents in wires A, B and C, we then know the current in wire N by Kirchhoff'sLaw and it is not necessary to measure it. This fact leads us to the conclusion of Blondell's Theoremthat we only need to measure the power in three of the four wires if they are connected by a commonnode. In the circuit of Figure D.6 we must measure the power flow in three wires. This will requirethree voltage coils and three current coils (a three element meter). Similar figures and conclusionscould be reached for other circuit configurations involving delta-connected loads.


Phase A

Phase B Phase C

Figure 1.6: Three-Phase Wye Load illustrating Kirchhoff’s Law and Blondell’s Theorem

Node “n”

A

B

N

C

Figure D.6: Three-Phase Wye Load Illustrating Kirchoff’s Lawand Blondell’s Theorem

D.2: Power, Energy and Demand

It is quite common to exchange power, energy and demand without differentiating between thethree. Because this practice can lead to confusion, the differences between these three measurements will be discussed.

Power is an instantaneous reading. The power reading provided by a meter is the present flow ofwatts. Power is measured immediately just like current. In many digital meters, the power value isactually measured and calculated over a one second interval because it takes some amount of time tocalculate the RMS values of voltage and current. But this time interval is kept small to preserve theinstantaneous nature of power.

Energy is always based on some time increment; it is the integration of power over a defined timeincrement. Energy is an important value because almost all electric bills are based, in part, on theamount of energy used.

Typically, electrical energy is measured in units of kilowatt-hours (kWh). A kilowatt-hour represents a constant load of one thousand watts (one kilowatt) for one hour. Stated another way, ifthe power delivered (instantaneous watts) is measured as 1,000 watts and the load was served for aone hour time interval then the load would have absorbed one kilowatt-hour of energy. A differentload may have a constant power requirement of 4,000 watts. If the load were served for one hour itwould absorb four kWh. If the load were served for 15 minutes it would absorb ¼ of that total orone kWh.

Figure D.7 shows a graph of power and the resulting energy that would be transmitted as a result ofthe illustrated power values. For this illustration, it is assumed that the power level is held constantfor each minute when a measurement is taken. Each bar in the graph will represent the power loadfor the one-minute increment of time. In real life the power value moves almost constantly.

The data from Figure D.7 is reproduced in Table 2 to illustrate the calculation of energy. Since thetime increment of the measurement is one minute and since we specified that the load is constantover that minute, we can convert the power reading to an equivalent consumed energy reading bymultiplying the power reading times 1/60 (converting the time base from minutes to hours).


Time (minutes)

Kilowatts

20

40

60

80

100

Figure 1.7: Power use over time Figure D.7: Power Use Over Time

Table D.2: Power and energy relationship over time

As in Table D.2, the accumulated energy for the power load profile of Figure D.7 is 14.92 kWh.

Demand is also a time-based value. The demand is the average rate of energy use over time. Theactual label for demand is kilowatt-hours/hour but this is normally reduced to kilowatts. This makesit easy to confuse demand with power. But demand is not an instantaneous value. To calculatedemand it is necessary to accumulate the energy readings (as illustrated in Figure D.7) and adjustthe energy reading to an hourly value that constitutes the demand.

In the example, the accumulated energy is 14.92 kWh. But this measurement was made over a 15-minute interval. To convert the reading to a demand value, it must be normalized to a 60-minute interval. If the pattern were repeated for an additional three 15-minute intervals the total energy would be four times the measured value or 59.68 kWh. The same process is applied to calculate the 15-minute demand value. The demand value associated with the example load is 59.68 kWh/hr or 59.68 kWd. Note that the peak instantaneous value of power is 80 kW, significantly more than thedemand value.


Time Interval(Minute) Power (kW) Energy (kWh) Accumulated

Energy (kWh)

1 30 0.50 0.502 50 0.83 1.333 40 0.67 2.004 55 0.92 2.925 60 1.00 3.926 60 1.00 4.927 70 1.17 6.098 70 1.17 7.269 60 1.00 8.26

10 70 1.17 9.4311 80 1.33 10.7612 50 0.83 12.4213 50 0.83 12.4214 70 1.17 13.5915 80 1.33 14.92

Figure D.8 shows another example of energy and demand. In this case, each bar represents the energy consumed in a 15-minute interval. The energy use in each interval typically falls between 50and 70 kWh. However, during two intervals the energy rises sharply and peaks at 100 kWh in interval number 7. This peak of usage will result in setting a high demand reading. For each intervalshown the demand value would be four times the indicated energy reading. So interval 1 would havean associated demand of 240 kWh/hr. Interval 7 will have a demand value of 400 kWh/hr. In thedata shown, this is the peak demand value and would be the number that would set the demandcharge on the utility bill.

As can be seen from this example, it is important to recognize the relationships between power, energy and demand in order to control loads effectively or to monitor use correctly.

D.3: Reactive Energy and Power Factor

The real power and energy measurements discussed in the previous section relate to the quantitiesthat are most used in electrical systems. But it is often not sufficient to only measure real power andenergy. Reactive power is a critical component of the total power picture because almost all real-lifeapplications have an impact on reactive power. Reactive power and power factor concepts relate toboth load and generation applications. However, this discussion will be limited to analysis of reactive power and power factor as they relate to loads. To simplify the discussion, generation willnot be considered.

Real power (and energy) is the component of power that is the combination of the voltage and thevalue of corresponding current that is directly in phase with the voltage. However, in actual practicethe total current is almost never in phase with the voltage. Since the current is not in phase with thevoltage, it is necessary to consider both the inphase component and the component that is at quadrature (angularly rotated 90o or perpendicular) to the voltage. Figure D.9 shows a single-phasevoltage and current and breaks the current into its in-phase and quadrature components.


Intervals

Kilowatt-hours

20

40

60

80

100

Figure 1.8: Energy use and demand Figure D.8: Energy Use and Demand

The voltage (V) and the total current (I) can be combined to calculate the apparent power or VA.The voltage and the in-phase current (IR) are combined to produce the real power or watts. The volt-age and the quadrature current (IX) are combined to calculate the reactive power.

The quadrature current may be lagging the voltage (as shown in Figure D.9) or it may lead the voltage. When the quadrature current lags the voltage the load is requiring both real power (watts)and reactive power (VARs). When the quadrature current leads the voltage the load is requiring realpower (watts) but is delivering reactive power (VARs) back into the system; that is VARs are flowing in the opposite direction of the real power flow.

Reactive power (VARs) is required in all power systems. Any equipment that uses magnetization tooperate requires VARs. Usually the magnitude of VARs is relatively low compared to the real powerquantities. Utilities have an interest in maintaining VAR requirements at the customer to a low valuein order to maximize the return on plant invested to deliver energy. When lines are carrying VARs,they cannot carry as many watts. So keeping the VAR content low allows a line to carry its fullcapacity of watts. In order to encourage customers to keep VAR requirements low, most utilitiesimpose a penalty if the VAR content of the load rises above a specified value.

A common method of measuring reactive power requirements is power factor. Power factor can bedefined in two different ways. The more common method of calculating power factor is the ratio ofthe real power to the apparent power. This relationship is expressed in the following formula:

Total PF = real power / apparent power = watts/VA

This formula calculates a power factor quantity known as Total Power Factor. It is called Total PFbecause it is based on the ratios of the power delivered. The delivered power quantities will includethe impacts of any existing harmonic content. If the voltage or current includes high levels of harmonic distortion the power values will be affected. By calculating power factor from the powervalues, the power factor will include the impact of harmonic distortion. In many cases this is thepreferred method of calculation because the entire impact of the actual voltage and current areincluded.

A second type of power factor is Displacement Power Factor. Displacement PF is based on theangular relationship between the voltage and current. Displacement power factor does not considerthe magnitudes of voltage, current or power. It is solely based on the phase angle differences. As a


V

I

IR

IX

Figure 1.9: Voltage and complex current

Angle θ

Figure D.9: Voltage and Complex Current

result, it does not include the impact of harmonic distortion. Displacement power factor is calculatedusing the following equation:

Displacement PF = cos θ, where θ is the angle between the voltage and the current (see Fig. D.9).

In applications where the voltage and current are not distorted, the Total Power Factor will equal theDisplacement Power Factor. But if harmonic distortion is present, the two power factors will not beequal.

D.4: Harmonic Distortion

Harmonic distortion is primarily the result of high concentrations of non-linear loads. Devices suchas computer power supplies, variable speed drives and fluorescent light ballasts make currentdemands that do not match the sinusoidal waveform of AC electricity. As a result, the current waveform feeding these loads is periodic but not sinusoidal. Figure D.10 shows a normal, sinusoidalcurrent waveform. This example has no distortion.

Figure D.10: Nondistorted Current Waveform

Figure D.11 shows a current waveform with a slight amount of harmonic distortion. The waveformis still periodic and is fluctuating at the normal 60 Hz frequency. However, the waveform is not asmooth sinusoidal form as seen in Figure D.10.


A Phase Current

-1500

-1000

-500

0

500

1000

1500

1 33 65

Figure D.11: Distorted current wave

The distortion observed in Figure D.11 can be modeled as the sum of several sinusoidal waveformsof frequencies that are multiples of the fundamental 60 Hz frequency. This modeling is performedby mathematically disassembling the distorted waveform into a collection of higher frequency waveforms. These higher frequency waveforms are referred to as harmonics. Figure D.12 shows thecontent of the harmonic frequencies that make up the distortion portion of the waveform in FigureD.11.

Figure D.12: Waveforms of the Harmonics

The waveforms shown in Figure D.12 are not smoothed but do provide an indication of the impactof combining multiple harmonic frequencies together.

When harmonics are present it is important to remember that these quantities are operating at higherfrequencies. Therefore, they do not always respond in the same manner as 60 Hz values.


Total A Phase Current with Harmonics

-1500

-1000

-500

0

500

1000

1500

1 33 65

Expanded Harmonic Currents

-250

-200

-150

-100

-50

0

50

100

150

200

250

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39Am

ps

2 Harmonic Current 3 Harmonic Current 5 Harmonic Current

7 Harmonic Current A Current Total Hrm

Inductive and capacitive impedance are present in all power systems. We are accustomed to thinkingabout these impedances as they perform at 60 Hz. However, these impedances are subject to frequency variation.

XL = jωL and

XC = 1/jωC

At 60 Hz, ω = 377; but at 300 Hz (5th harmonic) ω = 1,885. As frequency changes impedancechanges and system impedance characteristics that are normal at 60 Hz may behave entirely different in presence of higher order harmonic waveforms.

Traditionally, the most common harmonics have been the low order, odd frequencies, such as the3rd, 5th, 7th, and 9th. However newer, new-linear loads are introducing significant quantities of higher order harmonics.

Since much voltage monitoring and almost all current monitoring is performed using instrumenttransformers, the higher order harmonics are often not visible. Instrument transformers are designedto pass 60 Hz quantities with high accuracy. These devices, when designed for accuracy at low frequency, do not pass high frequencies with high accuracy; at frequencies above about 1200 Hzthey pass almost no information. So when instrument transformers are used, they effectively filterout higher frequency harmonic distortion making it impossible to see.

However, when monitors can be connected directly to the measured circuit (such as direct connection to 480 volt bus) the user may often see higher order harmonic distortion. An importantrule in any harmonics study is to evaluate the type of equipment and connections before drawing aconclusion. Not being able to see harmonic distortion is not the same as not having harmonic distortion.

It is common in advanced meters to perform a function commonly referred to as waveform capture.Waveform capture is the ability of a meter to capture a present picture of the voltage or currentwaveform for viewing and harmonic analysis. Typically a waveform capture will be one or twocycles in duration and can be viewed as the actual waveform, as a spectral view of the harmoniccontent, or a tabular view showing the magnitude and phase shift of each harmonic value. Data collected with waveform capture is typically not saved to memory. Waveform capture is a real-timedata collection event.

Waveform capture should not be confused with waveform recording that is used to record multiplecycles of all voltage and current waveforms in response to a transient condition.


D.5: Power Quality

Power quality can mean several different things. The terms ‘power quality’ and ‘power quality problem’ have been applied to all types of conditions. A simple definition of ‘power quality problem’ is any voltage, current or frequency deviation that results in mis-operation or failure ofcustomer equipment or systems. The causes of power quality problems vary widely and may originate in the customer equipment, in an adjacent customer facility or with the utility.

In his book “Power Quality Primer”, Barry Kennedy provided information on different types ofpower quality problems. Some of that information is summarized in Table D.3 below.

Table D.3: Typical power quality problems and sources

It is often assumed that power quality problems originate with the utility. While it is true that maypower quality problems can originate with the utility system, many problems originate with customer equipment. Customer-caused problems may manifest themselves inside the customer location or they may be transported by the utility system to another adjacent customer. Often, equipment that is sensitive to power quality problems may in fact also be the cause of the problem.

If a power quality problem is suspected, it is generally wise to consult a power quality professionalfor assistance in defining the cause and possible solutions to the problem.


Cause Disturbance Type Source

Impulse Transient Transient voltage disturbance,sub-cycle duration

Oscillatory transientwith decay

LightningElectrostatic dischargeLoad switchingCapacitor switching

Sag / swell

Interruptions

Undervoltage /Overvoltage

Voltage flicker

Harmonic distortion

Transient voltage, sub-cycleduration

RMS voltage, multiple cycleduration

RMS voltage, multiple second orlonger duration

RMS voltage, steady state,multiple second or longerduration

RMS voltage, steady state,repetitive condition

Steady state current or voltage,long term duration

Line/cable switchingCapacitor switchingLoad switching

Remote system faults

System protectionCircuit breakersFusesMaintenanceMotor startingLoad variationsLoad dropping

Intermittent loadsMotor startingArc furnaces

Non-linear loadsSystem resonance

Electro Industries/Gauge Tech Doc # E151-7-01 V1.01 Glossary-1

Glossary

0.1 Second Values: These values are the RMS values of the indicated quantity as calculated after approximately 50 milliseconds (3 cycles) of sampling.

1 Second Values: These values are the RMS values of the indicated quantity as calculated after one second (60 cycles) of sampling.

Alarm: An event or condition in a meter that can cause a trigger or call-back to occur.

Annunciator: A short label that identifies particular quantities or values displayed, for examplekWh.

Average (Current): When applied to current values (amps) the average is a calculated value that corresponds to the thermal average over a specified time interval. The interval is specified by the user in the meter profile. The interval is typically 15 minutes.So, Average Amps is the thermal average of amps over the previous 15-minute interval. The thermal average rises to 90% of the actual value in each time interval. For example, if a constant 100amp load is applied, the thermal average will indicate 90 amps after one time interval, 99 amps after two time intervals and 99.9 amps after three time intervals.

Average (Input Pulse When applied to Input Pulse Accumulations, the “Average” refers to the block Accumulations): (fixed) window average value of the input pulses.

Average (Power): When applied to power values (watts, VARs, VA), the average is a calculated value that corresponds to the thermal average over a specified time interval. Theinterval is specified by the user in the meter profile. The interval is typically 15 minutes. So, the Average Watts is the thermal average of watts over the previous 15-minute interval. The thermal average rises to 90% of the actual value in each time interval. For example, if a constant 100kW load is applied, the thermal average will indicate 90kW after one time interval, 99kW after two time intervals and 99.9kW after three time intervals.

Bit: A unit of computer information equivalent to the result of a choice between two alternatives (Yes/No, On/Off, for example).Or, the physical representation of a bit by an electrical pulse whose presence or absence indicates data.

Binary: Relating to a system of numbers having 2 as its base (digits 0 and 1).

Block Window Avg: The Block (Fixed) Window Average is the average power calculated over a (Power) user-set time interval, typically 15 minutes. This calculated average corresponds

to the demand calculations performed by most electric utilities in monitoring user power demand. (See Rolling Window Average.)


Byte: A group of 8 binary digits processed as a unit by a computer (or device) and used especially to represent an alphanumeric character.

CBEMA Curve: A voltage quality curve established originally by the Computer Business Equipment Manufacturers Association. The CBEMA Curve defines voltage disturbances that could cause malfunction or damage in microprocessor devices.The curve is characterized by voltage magnitude and the duration which the voltage is outside of tolerance. (See ITIC Curve.)

Channel: The storage of a single value in each interval in a load profile.

Cold Load Pickup This value is the delay from the time control power is restored to the time whenthe useer wants to resume demand accumulation.

CRC Field: Cyclic Redundancy Check Field (Modbus communication) is an error checksum calculation that enables a Slave device to determine if a request packet from a Master device has been corrupted during transmission. If the calculated value does not match the value in the request packet, the Slave ignores the request.

CT (Current) Ratio: A Current Transformer Ratio is used to scale the value of the current from a secondary value up to the primary side of an instrument tranformer.

Cumulative Demand: The sum of the previous billing period maximum demand readings at the time of billing period reset. The maximum demand for the most recent billing periodis added to the previously accumulated total of the maximum demands.

Demand: The average value of power or a similar quantity over a specified period of time.

Demand Interval: A specified time over which demand is calculated.

Display: User-configurable visual indication of data in a meter.

DNP 3.0: A robust, non-proprietary protocol based on existing open standards. DNP 3.0 is used to operate between various systems in electric and other utility industries and SCADA networks.

EEPROM: Nonvolatile memory. Electrically Erasable Programmable Read Only Memory that retains its data during a power outage without need for a battery. Also refers to meter’s FLASH memory.

Energy Register: Programmable record that monitors any energy quantity. Example: Watthours, VARhours, VAhours.

Ethernet: A type of LAN network connection that connects two or more devices on a common communications backbone. An Ethernet LAN consists of at least one hub device (the network backbone) with multiple devices connected to it in a star configuration. The most common versions of Ethernet in use are 10BaseT


or 100BaseT as defined in IEEE 802.3 standards. However, several other versions of Ethernet are also available.

Exception Response: Error Code (Modbus communication) transmitted in a packet from the Slave to the Master if the Slave has encountered an invalid command or other problem.

Flicker: The sensation experienced by the human visual system when it is subjected to changes occurring in the illumination intensity of light sources. IEC 61000-4-15 and former IEC 868 describe the methods used to determine Flicker severity.

Form: Wiring and Hookup configuration for the Nexus 1260/1262 & 1270/1272.

Harmonics: Measuring values of the fundamental current and voltage and percent of the fundamental.

Heartbeat Pulse: Energy indicator on the face of the Nexus 1250/1252; pulses are generated per the programmed Ke value.

I2T Threshold: Data will not accumulate until current reaches programmed level.

Infrared Test Pulse: Energy indicator located on the upper left side of the face of the Nexus 1260/ 1262 & 1270/1272 meters; pulses are generated per the programmed Ke value.

Integer: Any of the natural numbers, the negatives of those numbers or zero.

Internal Modem: An optional modem within the meter’s enclosure that connects to the RJ-11 telephone connector.

Invalid Register: In the Nexus Modbus Map there are gaps between Registers. For example, the next Register after 08320 is 34817. Any unmapped Register stores no information and is said to be invalid.

ITIC Curve: An updated version of the CBEMA Curve that reflects further study into the performance of microprocessor devices. The curve consists of a series of steps but still defines combinations of voltage magnitude and duration that will cause malfunction or damage.

Ke: kWh per pulse; i.e. the energy.

kWh: kilowatt hours; kW x demand interval in hours.

KYZ Output: Output where the rate of changes between 1 and 0 reflects the magnitude of a metered quantity.

LCD: Liquid Crystal Display.

LED: Light Emitting Diode.


Master Device: In Modbus communication, a Master Device initiates and controls all information transfer in the form of a Request Packet to a Slave Device. The Slave reponds to each request.

Maximum Demand: The largest demand calculated during any interval over a billing period.

Modbus ASCII: Alternate version of the Modbus protocol that utilizes a different data transfer format. This version is not dependent upon strict timing, as is the RTU version. This is the best choice for telecommunications applications (via modems).

Modbus RTU: The most common form of Modbus protocol. Modbus RTU is an open protocolspoken by many field devices to enable devices from multiple vendors to communicate in a common language. Data is transmitted in a timed binary format, providing increased throughput and therefore, increased performance.

Network: A communications connection between two or more devices to enable those devices to send and receive data to one another. In most applications, the network will be either a serial type or a LAN type.

NVRAM: Nonvolatile Random Access Memory is able to keep the stored values in memory even during the loss of circuit or control power. High speed NVRAM is used in the Nexus to gather measured information and to insure that no information is lost.

Optical Port: A port that facilitates infrared communication with a (1260/1262 or 1270/1272) meter. Using an ANSI C12.13 Type II magnetic optical communications coupler and an RS-232 cable from the coupler to a PC, the meter can be programmed with Nexus Communicator software.

Packet: A short fixed-length section of data that is transmitted as a unit. Example: a serial string of 8-bit bytes.

Percent (%) THD: Percent Total Harmonic Distortion.

Protocol: A language that will be spoken between two or more devices connected on a network.

PT Ratio: Potential Transformer Ratio used to scale the value of the voltage to the primary side of an instrument transformer. Also referred to as VT Ratio.

Pulse: The closing and opening of the circuit of a two-wire pulse system or the alternate closing and opening of one side and then the other of a three-wire system (which is equal to two pulses).

Q Readings: Q is the quantity obtained by lagging the applied voltage to a wattmeter by 60 degrees. Values are displayed on the Uncompensated Power & Q Readings screen.


Quadrant: Watt and VAR flow is typically represented usng an X-Y coordinate system. (Programmable The four corners of the X-Y plane are referred to as quadrants. Most power Values and Factors applications label the right hand corner as the first quadrant and number the on the Nexus) remaining quadrants in a counter-clockwise rotation. Following are the

positions of the quadrants: 1st - upper right, 2nd - upper left, 3rd - lower left and 4th - lower right. Power flow is generally positive in quadrants 1 and 4. VAR flow is positive in quadrants 1 and 2. The most common load conditions are: Quadrant 1 - power flow positive, VAR flow positive, inductive load, lagging or positive power factor; Quadrant 2 - power flow negative, VAR flow positive, capacitive load, leading or negative power factor.

Register: An entry or record that stores a small amount of data.

Register Rollover: A point at which a Register reaches its maximum value and rolls over to zero.

Reset: Logs are cleared or new (or default) values are sent to counters or timers.

Rolling Window The Rolling (Sliding) Window Average is the average power calculated over a Average (Power): user-set time interval that is derived from a specified number of sub-intervals,

each of a specified time. For example, the average is calculated over a 15-minute interval by calculating the sum of the average of three consecutive 5-minute intervals. This demand calculation methodology has been adopted by several utilities to prevent customer manipulation of kW demand by simply spreading peak demand across two intervals.

RS-232: A type of serial network connection that connects two devices to enable communication between devices. An RS-232 connection connects only two points. Distance between devices is typically limited to fairly short runs. Current standards recommend a maximum of 50 feet but some users have had success with runs up to 100 feet. Communications speed is typically in the range of 1200 bits per second to 57,600 bits per second. RS-232 communication can be accomplished using the Optical port on the face of the Nexus 1260/1262 or 1270/1272.

RS-485: A type of serial network connection that connects two or more devices to enable communication between the devices. An RS-485 connection will allow multi-drop communication from one to many points. Distance between devices is typically limited to around 2,000 to 3,000 wire feet. Communications speed is typically in the range of 120 bits per second to 115,000 bits per second.

Sag: A voltage quality event during which the RMS voltage is lower than normal for a period of time, typically from 1/2 cycle to 1 minute.

Secondary Rated: Any Register or pulse output that does not use any CT or VT Ratio.

Serial Port: The type of port used to directly interface with a PC.

Slave Device: In Modbus communication, a Slave Device only receives a Request Packet from a Master Device and responds to the request. A Slave Device cannot initiate


communication.

Swell: A voltage quality event during which the RMS voltage is higher than normal for a period of time, typically from 1/2 cycle to 1 minute.

THD: Total Harmonic Distortion is the combined effect of all harmonics measured in avoltage or current. The THD number is expressed as a percent of the fundamental. For example, a 3% THD indicates that the magnitude of all harmonic distortion measured equals 3% of the magnitude of the fundamental 60Hz quantity.

Time Stamp: A stored representation of the time of an event. Time Stamp can include year, month, day, hour, minute and second and Daylight Savings Time indication.

TOU: Time of Use.

Uncompensated Power: VA, Watt and VAR readings not adjusted by Transformer Loss Compensation.

V2T Threshold: Data will stop accumulating when voltage falls below programmed level.

Voltage Imbalance: The ratio of the voltage on a phase to the average voltage on all phases.

Voltage Quality Event: An instance of abnormal voltage on a phase. The events the meter will track include sags, swells, interruptions and imbalances.

VT Ratio: The Voltage Transformer Ratio is used to scale the value of the voltage to the primary side of an instrument transformer. Also referred to as PT Ratio.

Voltage, Vab: Vab, Vbc, Vca are all Phase-to-Phase voltage measurements. These voltages aremeasured between the three phase voltage inputs to the meter.

Voltage, Van: Van, Vbn, Vcn are all Phase-to-Neutral voltages applied to the monitor. These voltages are measured between the phase voltage inputs and Vn input to the meter. Technologically, these voltages can be “measured” even when the meter is in a Delta configuration and there is no connection to the Vn input. However,in this configuration, these voltages have limited meaning and are typically not reported.

Voltage, Vaux This is the fourth voltage input measured from between the Vaux and Vref inputs. This input can be scaled to any value. However, the actual input voltage to the meter should be of the same magnitude as the voltages applied to the Va, Vb and Vc terminals.

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