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): QQQX2Standard Number: UL 1557Standard Title: Standard for Electrically Isolated Semiconductor DevicesEdition Date: December 29, 2011Edition Number: 5Section / Paragraph Reference: 14Subject: Productio
3、n Line Dielectric Voltage-Withstand Test addition of dc testDECISION:MANUFACTURING AND PRODUCTION-LINE TEST14 Dielectric Voltage-Withstand Test14.1 Each product shall withstand without electrical breakdown, as a routine production-line test, theapplication of a potential at a frequency within the ra
4、nge of 40 - 70 Hz between live parts and accessibledead metal partsException: A dc potential equal to 1.414 times the specified 40 - 70 Hz potential may be used.14.2 The production-line test potential shall be the rated isolation rms voltage for 60 seconds or 120percent of the rated isolation rms vo
5、ltage for one second.Exception: For a dc test potential:1.414 times the rated isolation rms voltage for one minute or1.414(1.2) times the rated isolation rms voltage for one second.14.3 The product may be in a heated or unheated condition for the test.14.4 For an ac test, tThe test equipment shall i
6、nclude a transformer having an essentially sinusoidaloutput, a means of indicating the test potential, an audible or visual indicator of electrical breakdown, andeither a manually reset device to restore the equipment after electrical breakdown or an automatic featurethat rejects any unacceptable un
7、it.RATIONALE FOR DECISION:Added equivalent production line dc dielectric test.Copyright 2017 UL LLCUL LLC, in performing its 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 o
8、r adoptedby anyone. Certification Requirement Decisions are the opinion of UL LLC. in practically applying therequirements 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 any
9、one forUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULthe use of or reliance upon Certification Requirement Decisions by anyone. UL LLC shall not incur anyobligation or liability for damages, including consequential damages, arising out of or
10、 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 1557 -2-
