ELECTRICAL SYSTEM

GROUNDING CALCULATIONDocument Number

Revision: 0A Status: IFR

Document Type: CAL System / Subsystem: Discipline: ELE Rev. Date:

CONTRACTOR DOCUMENT: Page: 8 of 8

APGREID SUBSTATION PROJECT

ELECTRICAL SYSTEM GROUNDING CALCULATION

REV.STATUSDATEREVISION MEMOISSUEDCHECKAPPR.COMPANY APPROVAL

0AIFRIssued For Review

REVISION TABLE

PAGESREVISIONSREMARKSATTACHMENTSREMARKS

ABCDEATTPAGESREVISIONS

ABCDE

EXHIBITPAGESREVISIONSREMARKS

ABCDE

41.GENERAL

42.REFERENCES

43.ABBREVIATION

54.SCOPE

54.1Electrical system neutral grounding

54.2Electrical safety grounding

54.3Electrostatic grounding

55.GROUNDING CALCULATION PARAMETER

55.1Soil resistivity

55.2Grounding conductor

65.3Grounding electrode

75.4Tolerable step and touch voltage

76.GROUNDING CALCULATION ANALYSIS RESULT

1. GENERAL

The purpose of this document is to give guidance on the design of the grounding and lightning protection system. The grounding system is provided for the safety of personnel, equipment and the proper operation of the plant. The project specifications and the applicable international standards are listed

This calculation will be revised whenever necessary to cope up with the changes on the system components that may be caused by further engineering.2. REFERENCESThe grounding and lightning protection system shall be design in accordance with the applicable sections of the following standards and codes:

IEEE 142IEEE Recommended Practice for Grounding of Industrial and Commercial Power Systems

IEEE 80-2000Guide for Safety in AC Substation Grounding

NFPA 70National Electrical Code

NFPA 780Standard for the Installation of Lightning Protection System

Soil Investigation Report

3. ABBREVIATIONkVAKilo Volt Ampere

MVAMega Volt Ampere

PFPower Factor

LFLoad Factor

ACSRAluminum conductors steel reinforced

GCBGenerator Circuit Breaker

HVHigh Voltage

LVLow Voltage

LVSBLow Voltage Switch Board

MDBMain Distribution Board

SDBSub Distribution Board

DBDistribution Board

EsEssential

EEmergency

4. SCOPEThis document includes the following systems:

4.1 Electrical system neutral grounding

The electrical ground system in medium voltage (>1000V) distribution system shall be done by either isolation of transformer star point or by grounding the transformer star point via a resistor.

The electrical ground system in low voltage (