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): NMMS/2Standard Number: UL 61800-5-1Standard Title: Standard for Standard For Safety For Adjustable Speed ElectricalPower Drive Systems - Part 5-1: Safety Requirements - Electrical, Thermal andEnergyEd
3、ition Date: June 8, 2012Edition Number: 1Section / Paragraph Reference: 4.3.8.4DV.2, 5.2.3.8DV.3Subject: Heat Cycling Test for Spring-loaded Bus Bar JointsDECISION:4.3.8.4DV.2 D2 Modification to add the following:Bus bars using spring-loaded joints for connection shall be subjected to the heat cycli
4、ng test of5.2.3.8DV.3. A spring-loaded joint shall be considered to be one in which the clamping force is developedby the deflection of a spring member in the assembly of the joint or developed by the elasticity of a metalclamp or clip in the assembly of the joint. For the purpose of this requiremen
5、t, a dished washer shall notbe considered to exert spring loading and would not be required to be evaluated using the heat cyclingtest.5.2.3.8DV.3 Modification to add the following:5.2.3.8DV.3.1 Heat Cycling Test5.2.3.8DV.3.1.1 Spring-loaded bus bar joints as described in 4.3.8.4DV.2 shall be subjec
6、ted to a heatcycling test.5.2.3.8DV.3.1.2 For the heat cycling test, the rated bus bar current shall vary in cycles in the mannerdescribed in Clauses 5.2.3.8DV.3.2.1 and 5.2.3.8DV.3.2.2. Results shall comply with the limitations onincrease in temperature rise specified in Clause 5.2.3.8DV.3.2.2.5.2.
7、3.8DV.3.1.3 The spring-loaded joints shall be conditioned by being assembled and disassembled 5times prior to final assembly for the test.5.2.3.8DV.3.2 Heat Cycling Test arrangement5.2.3.8DV.3.2.1 The temperature rises on the contacts of the spring-loaded bus bar joint shall bedetermined while the e
8、quipment is carrying the specified current continuously. After temperatures havebecome constant under these conditions, the current shall be stopped and the equipment shall be allowedto cool to room temperature.5.2.3.8DV.3.2.2 The equipment shall then be subjected to two successive sets of cycling o
9、f the current.Each set shall consist of 42 complete cycles. During each cycle the current shall be on for 2 hours andoff for 2 hours; or if, during the initial heating mentioned in Clause 5.2.3.8DV.3.2.2, average temperatureson the spring-loaded bus bar joint at the end of 2 hours are more than 5C l
10、ower than the average finaltemperatures during continuous operation, the current shall remain on for 3 hours in each cycle. StableUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULmaximum temperatures shall be observed again after the 42nd cycle
11、 and also after the 84th cycle. Thefinal temperatures shall not be more than 5C higher than those observed initially, nor shall the finaltemperatures be more than 5C higher than those observed at the conclusion of the 42nd cycle.RATIONALE FOR DECISION:Field installed bus bars are becoming more commo
12、n in drives that use a distributed bus system, such asmodular drive systems. Methods for connection of these bus bars may include spring loaded connectionsor clamps. These requirements are to address the concern of these types of connections for bus bars andare based on requirements from UL 857, the
13、 Standard for Safety for Busways, section 8.2.1.4.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 or adoptedby anyone. Certific
14、ation 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 anyone forthe use of or relianc
15、e upon Certification Requirement Decisions by anyone. UL LLC shall not incur anyobligation or liability 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 61800-5-1 -2-
