UL 1449 CRD-2015 UL Standard for Safety Surge Protective Devices - Section Paragraph Reference 1 1 Subject DC rated SPDs for DC Power Circuits Not Exceeding 1500 V dc Supersedes p.pdf

1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULUNDERWRITERS LABORATORIES INC. CERTIFICATION REQUIREMENT DECISIONThis Certification Requirement Decision is prepared and published by Underwriters Laboratories Inc.(UL). It is normative for the a

2、pplicable UL Product Certification Program(s); however, it is currently notpart of the UL Standard(s) referenced below.Product Category (CCN): VZCA, VZCA2Standard Number: UL 1449Standard Title: Standard for Surge Protective DevicesEdition Date: August 20, 2014Edition Number: 4Section / Paragraph Ref

3、erence: 25.1, 72.2Subject: 1) Using 2 X capacitors in Place of a Y Capacitor; 2) Revision of thecapacitor failure test for UL 60384-14 CapacitorsDECISION:25.1 Capacitors other than those employed in a secondary circuit shall comply with the DielectricVoltage-Withstand Test, Section 38, Insulation Re

4、sistance Test, Section 53, and Capacitor EnduranceTest, Section 54.Exception No. 1: Capacitors evaluated to the Dielectric Voltage-Withstand Test, Insulation ResistanceTest and Capacitor Endurance Test of the Standard for Electromagnetic Interference Filters, UL 1283 arenot required to be subjected

5、to these tests.Exception No. 2: Capacitors that comply with the requirements in the Standard for Fixed Capacitors forUse in Electronic Equipment, UL 60384-14 and are rated for the intended application, including operatingvoltage, subclass, Upper and Lower Temperature rating as follows:a) X Capacitor

6、s can be used in L-L and L-N applications only without additional testing perClause 25.1.b) Y Capacitors can be used in L-L, L-N, L-G and N-G applications without additional testingper Clause 25.1.Exception: Two X capacitors in series, may be substituted for a Y capacitor providing that eachcapacito

7、r is rated 1.36/2= 0.68 times the voltage rating required for a Y capacitorNote: Since the endurance testing of Y capacitors is at 1.7 x the rated voltage and the endurance testing forX capacitors is at 1.25 X the rated voltage, the X capacitor needs to be rated at 1.36 times the rating of the Ycapa

8、citor(1.25URX =1.7URY; URX= 1.36URY).Therefore, with two X capacitors in series, each capacitorwould need to be rated 1.36/2= .68 times the voltage rating of the Y capacitor.c) Duration of the damp-heat test (21 or 56 days) does not need to be considered.d) Passive flammability category does not nee

9、d to be considered.e) Overvoltage Class and Peak Surge Voltage properties do not need to be consideredprovided that the capacitors are tested as part of the SPD during the end-product SPD SurgeTesting per UL 1449 Section 40.UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTI

10、ON WITHOUT PERMISSION FROM UL72.2 Capacitors that comply with the requirements in the Standard for Fixed Capacitors for Use inElectronic Equipment, UL 60384-14, as indicated in Exception 2 of Paragraph 25.1, rated 1 uF or less maybe failed in accordance with 72.1, or may be replaced with jumper wire

11、 having a minimum gauge sizeequal to the capacitor leads. The jumper wire shall not open during testing.RATIONALE FOR DECISION:1) To allow two X Capacitors in Place of a Y Capacitor; 2) The pre-failing method of 72.1 does not workwith fixed capacitors evaluated to UL60384-14, since these capacitors

12、do not stay shorted long enough orthe short is not substantial enough to meet the criteria of 72.1. Shorting the cap with a jumper will simulatea shorted capacitor and determine if a hazardous condition exists.Copyright 2015 Underwriters Laboratories Inc.UL, in performing its functions in accordance

13、 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 Underwriters Laboratories Inc. inpractically applying the requirements of

14、 the standard. They do not represent formal interpretations of thestandard under American National Standards Institute (ANSI) processes. UL shall not be responsible toanyone for the use of or reliance upon Certification Requirement Decisions by anyone. UL shall not incurany obligation or liability f

15、or damages, including consequential damages, arising out of or in connectionwith the use or reliance upon Certification Requirement Decisions. The electronic version of theCertification Requirement 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 1449 -2-