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Industrial Control Panels

UL508A

Dirk Müller

UL 508A Online Certifications Directory

Underwriters Laboratories

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UL 508A Online Certifications Directory

Outline of UL 508A

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Industrial

Control

Procedure

UL508A

Descriptive

Procedure

Part 1

General Use

Supplement SA

Specific Component

Requirements

Part 2

Specific Use

Information you provide

Specific components not

covered in UL508A

Supplement SB

Short Circuit Current Ratings

Appendix B

Use of Unlisted Components

Appendix A

Standards for Components

UL 508A Online Certifications Directory

Clause 1.2 – Also Covers Specialty Type

Industrial Control Panels and Enclosures

• Flame safety supervision of

combustible fuel type equipment

• Elevator control

• Crane or hoist control

• Service equipment use

• Marine use

• Custom built Type 1 enclosures

• Air conditioning

• Refrigeration equipment

• Control of industrial machinery

including metalworking machine

tools, power press controls, and

plastic injection molding machinery

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UL 508A Online Certifications Directory

Online Certifications Directory

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www.ul.com/database/

UL 508A Online Certifications Directory

Terminal Block Example

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XCFR2

Terminal Blocks - ComponentsSee General Information for Terminal Blocks - Component

Cat. No.

Wire

Range

Wire

Type FW

TQ

Lb In. V A UG CA

50 PLTVV## 22-12 CU 2 20 300 20 C,D 2(105C),*

60 PLTVV## 18-12 CU 2 20 600 20 C 2(105C),*

80 PLTVV## 18-8 CU 2 20 600 50 C 2(105C),*

M6/8,D2##, 18-8 CU 2 7.1-20 600 50 C 2(105C),*

Note: ## May be provided with suffix TR.

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Section 6 Terminology

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UL 508A Online Certifications Directory

Single Motor Branch Circuit Protection Sizing

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Step 3: Check Starter for

Specific Instructions

BCP

Starter

MotorStep 1: Determine Motor

Full Load Amps

Step 2: Size Protection Per

Table 31.1 Based on Type

of Device

UL 508A Online Certifications Directory

Single Branch Circuit Protection Sizing

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Step 3:

Starter does not indicate type of protection

Step 1:

Motor is 480 V, 3 Ø, 7-1/2 HP.

Per Table 50.1, FLA is 11.0 Amps

Step 2:

31.3.1:For a UL Listed Circuit Breaker

11.0 Amps x 250%=27.5 Amps

Breaker Size shall not exceed 30 Amps

(If calculation results in a non-standard

size, the next highest standard

size may be selected)

BCP

Starter

Motor

UL 508A Online Certifications Directory

Clause 37.4 – Segregation of Field Wiring

Terminals of Class 2 Circuits

• Terminals for connection to Class 2 circuits shall be

• Segregated with a minimum permanent 2 in. separation, or

• Separated by a barrier

• from any non-Class 2 field-installed wires, and

• Marked as a Class 2 control circuit

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UL 508A Online Certifications Directory

Industrial Control Panels – General Programs

• Field Evaluation (FEP)

• Evaluated and labeled by UL at installation site

• Listing Program

• Provides evidence of third-party certification

• One-of-a-kind panels or standardized designs

• Open or enclosed panels

• Listing mark applied by manufacturer in factory

• Limited Production Program

• Listing of individual products

• No continous production and factory inspections

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UL 508A Online Certifications Directory

News from the 2017 NEC

• This requirement is NOT for the panel builder but the responsibility of

the operator of the plant or facility!

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UL 508A Online Certifications Directory

UL508A 2nd: Multiple Revision in 2017

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• Alignment of UL508A with NEC: Voltage limit from 600V to 1000V

• Table Sa 1.2 for guidance of usage for ECBT2 Connectors

• SCCR rating, Voltage and Current ratings

• SB 4.3.1 Calculation of SCCR rating using a transformer

• More options than before

• And few others

UL 508A Online Certifications Directory

Questions

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