1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULUNDERWRITERS LABORATORIES INC. CERTIFICATION REQUIREMENT DECISIONThis Certification Requirement Decision is prepared by UL LLC. It is normative for the applicable ULProduct Certification Program(
2、s); however, it is currently not part of the UL Standard(s) referencedbelow.Product Category (CCN): NITWStandard Number: UL 508AStandard Title: Standard for Industrial Control PanEdition Date: December 20, 2013Edition Number: 2Section / Paragraph Reference: Sections 29.3.4, 29.3.5.1 (New), SB3.1 and
3、 SB4.2Subject: Wiring Ferrules for use in Industrial Control PanelsDECISION:29.3.4 A connection to a terminal of a component shall be made by:a) Wire inserted directly into a pressure wire terminal of the component;b) Quick-connect terminal of the component, where the mating part is provided with a
4、dimple,depression, or spring-type connection such that a mechanical snap-action connection is madethat does not rely solely upon friction between the two parts;c) Crimped-on pressure terminal connector or closed-loop eyelet;d) Solder terminal specified in 29.3.2;e) Wire-binding screw specified in 29
5、.3.3; orf) Open-type eyelet specified in 29.3.5.g) Wiring ferrule specified in 29.3.5.1.29.3.5.1 A wiring ferrule shall be:a) Used with stranded copper wire(s) onlyb) Terminated in a connector rated for copper wire and rated for the number and size of wire(s)crimped to the ferrule.c) Crimped with an
6、 appropriate tool as recommended by the ferrule manufacturer beforeterminating in a terminal of a component.d) Sized in diameter appropriate for the number of wires and wire size(s) as recommended bythe ferrule manufacturer.e) Crimped to the wires such that the length of the uninsulated portion of t
7、he wires does notresult in the reduction of electrical spacings when the ferrule is installed.SB3.1 Internal wiring connectionsUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULSB3.1.1 All terminals of power circuit wiring connectors, wiring fer
8、rules and components shall be torquedto the manufacturers specified value or crimped-on according to the manufacturers instructionsSB4.2 Short circuit current ratings of individual power circuit componentsSB4.2.1 All power circuit components, including disconnect switches, branch circuit protective
9、devices,branch circuit fuseholders, load controllers, motor overload relays, terminal blocks, and bus bars, shallhave a short circuit current rating expressed in amperes or kiloamperes and voltage.Exception No. 1: Power transformers, reactors, current transformers, dry-type capacitors, resistors,var
10、istors, and voltmeters are not required to have a short circuit current rating.Exception No. 2: The S contactor of a wye-delta motor controller is not required to have a short circuitcurrent rating.Exception No. 3: Wiring ferrules are not required to have a short circuit current rating, provided tha
11、t therequirements of 29.3.5.1 are met.RATIONALE FOR DECISION:Wiring ferrules are commonly used to facilitate connection of internal wiring in industrial control panels.The use of ferrules is currently not addressed by UL 508A. Ferrules are limited to factory installation sincespecialized tools and c
12、ontrol of their use must be applied to the installation. Any manufacturers ferrulesare suitable for use in factory wiring only, power or control circuits. As ferrules are an extension of aconductor, no short circuit current rating is required or assigned.Copyright 2016 UL LLCUL LLC, in performing it
13、s functions in accordance with its objectives, does not guarantee or warrant thecorrectness of Certification Requirement Decisions it may issue or that they will be recognized or adoptedby anyone. Certification Requirement Decisions are the opinion of UL LLC. in practically applying therequirements
14、of the standard. They do not represent formal interpretations of the standard underAmerican National Standards Institute (ANSI) processes. UL LLC shall not be responsible to anyone forthe use of or reliance upon Certification Requirement Decisions by anyone. UL LLC shall not incur anyobligation or l
15、iability for damages, including consequential damages, arising out of or in connection withthe use or reliance upon Certification Requirement Decisions. The electronic version of the CertificationRequirement Decision is the current version and previously printed copies may be outdated.This document is published as a service to ULs certification customersSTANDARD NUMBER: UL 508A -2-
