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): XAPXStandard Number: UL 873Edition Date: November 16, 2007Edition Number: 12Section / Paragraph Reference: 29, 38, 69Subject: Requirements for controls incor
3、porating equipment ground-fault protectionintended for use in fixed outdoor electric deicing and snow-melting equipmentDECISION:29 Short-Circuit, Ground-Fault, Overload, and Thermal Protection29.3 Controls intended for use in fixed outdoor electric deicing and snow-melting equipment thatincorporate
4、equipment ground-fault protective devices (EGFPD) in its design, shall comply with therelevant requirements of this standard and also the referenced requirements of the Standard forGround-Fault Sensing and Relaying Equipment, UL 1053. See 38.10 of UL 873.29.4 The EGFPD circuit of an ice and snow-mel
5、ting equipment control shall comply with section 38.10.1.If the control is not provided with an alarm or test means to indicate an inoperative EGFPD condition, theEGFPD function of the control shall be evaluated as a protective function in accordance with the relevantrequirements of this standard, a
6、nd the Standard for Tests for Safety-Related Controls EmployingSolid-State Devices, UL 991. If software is relied upon as part of the electronic control, it shall beevaluated in accordance with the Standard for Software in Programmable Components, UL 1998 asSoftware Class 1.29.5 An ice and snow melt
7、ing equipment control may be provided with a common switching device tocontrol normal operation and provide EGFPD functionality. The control shall be marked in accordance with69.27.38.10 Ice and Snow-Melting Equipment Controls38.10.1 In addition to the applicable performance requirements of this sta
8、ndard, a EGFPD operation of anice and snow-melting equipment control shall be subjected to the following tests of UL 1053:a) Calibration Test sequence of Section 21. Devices with adjustable fault current setpoints, thecalibration sequence is conducted at the minimum and maximum values of the range.b
9、) Current Withstand Test of Section 27. This test is conducted at the short circuit valuesspecified in Table 50.2 of UL873.c) The Calibration Test of Section 21 shall be repeated after the Current Withstand Test atroom ambient.d) The Dielectric Voltage-Withstand Test of Section 25 shall be conducted
10、 after each test asappropriate, ande) The Component Failures Test of Section 26.UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL69.27 With reference to 29.5 and to avoid misuse of the equipment, deicing and snow-melting controlsshall be marked
11、 with the following or equivalent : “This device provides ground-fault protection of theequipment required by the National Electrical Code. This device does not provide personal GFCIprotection”.RATIONALE FOR DECISION:Multi-function controls intended for use in fixed outdoor ice and snow-melting equi
12、pment can be providedwith integrated equipment ground-fault protective devices (EGFPD). These type of controls have beenevaluated to the Standard for Temperature-Indicating-and-Regulating Equipment, UL 873. Currently, UL873 does not have specific requirements to address provision of EGFPD in multi-f
13、unction controls used inice and snow-melting equipment.Since Article 426.28 of the National Electrical Code (NEC) requires EGFPD for ice and snow-meltingequipment, all multi-function controls that provide this functionality shall be investigated with the applicableEGFPD requirements. As an alternati
14、ve, the snow-melting equipment may also utilize separate EGFPDdevices in the equipment. UL1053, the Standard for Safety for Ground-Fault Sensing and RelayingEquipment details these applicable EGFPD requirements. This decision reflects current practice.Copyright 2010 Underwriters Laboratories Inc.UL,
15、 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. Certification Requirement Decisions are the opinion of Underwriters Laboratories Inc.
16、inpractically applying the requirements of 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 sh
17、all not incurany obligation or liability for 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 873 -2-
