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): WMUZStandard Number: UL 20Standard Title: Standard for General-Use Snap SwitchesEdition Date: May 10, 2010Edition Number: 13Section / Paragraph Reference: Pa
3、ra. 2.10.1, Sections 4.4, 4.5.3, 5.2.10, 5.28, 7.1,Tables 5.28.1, Figures 5.28.1, 5.28.2Subject: Flush Switches Employing A Combination Wire Binding/Pressure-TypeTerminal ConstructionDECISION:This CRD documents the requirements for a new terminal design.The terminal consists of a traditionalwire bin
4、ding screw that is machined to employ an integrally formed pressure ring. The pressure ringresembles a screw and washer type design. This integrally formed pressure ring enables the flush switchto be wired as a back-wired terminal, accepting multiple conductors captured under the integrally formedpr
5、essure ring. The body of the switch is also modified to include integrally molded channels/guidesnecessary to: (1) properly position each individual conductor, and, (2) provide a mechanical means toprevent the conductor from being pushed away from under the terminal ring.(NEW) 2.10.1 TERMINAL, COMBI
6、NATION WIRE BINDING/PRESSURETYPE A wire binding screwwith an integrally machined pressure ring. Pressure ring terminals accept both single and multipleconductors that are captured under the machine formed pressure ring. These terminals may be wired witha single conductor using the conventional 3/4 l
7、oop around the wire-binding screw.4 Construction4.4 Bases and Bodies(New) 4.4.1.4 The body of switch employing a combination wire binding/pressure-type terminal shallemploy integrally formed channels/guides within the body to:a) Properly position individual conductor, andb) Provide a means to reduce
8、 the likelihood of the conductor(s) being displaced from under theterminal ring when conductor(s) are installed.Compliance is determined by the Combination Wire Binding/Pressure-Type Terminal Assembly Testdescribed in Section 5.28.4.5.3 Terminals and Leads(New) 4.5.3.7.1 Switches employing a combina
9、tion wire binding/pressure-type terminal shall be limited to10, 12 or 14 AWG conductors. The terminals shall comply with the applicable performance requirementsas specified in UL 486E. See also 1.10 for terminals intended for use with aluminum conductors.5.2 Test SequenceUL COPYRIGHTED MATERIAL NOT
10、AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL(Revised) 5.2.10 AC only flush switch testingReferencea) Contact gap 5.13.1.2b) Overload 5.6.8 - 5.6.12c) Endurance No. 1 (resistive) 5.7.6d) Endurance No. 2 (inductive) 5.7.7e) Endurance No. 3 (tungsten) 5.7.8f) Temperatur
11、e 5.8.1g) Contact gap (repeated) 5.13.1.2h) Dielectric 5.9.1i) Security of leads 5.10j) Pull-out/push-in terminals 5.11.1, 5.11.2k) Temperature/push-in terminals 5.11.3 - 5.11.8l) Effect of heat on actuating members 5.12m) Resistance to heat (70C) 5.17n) Combination Wire Binding/Pressure-Type Termin
12、al Assembly 5.28(New) 5.28 Combination Wire Binding/Pressure-Type Terminal Assembly Test(New) 5.28.1 A flush switch employing a combination wire binding/pressure-type terminals shall notexhibit:a) Damage to the switch, including but not limited to breakage of the housing, or stripping ofthe terminal
13、, andb) Visible displacement of the conductors following the pull test described in 5.28.5.(New) 5.28.2 A flush switch employing a combination wire binding/pressure-type terminal shall be wiredas outlined in Table 5.28.1.STANDARD NUMBER: UL 20 -2-UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER RE
14、PRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL(New) Table 5.28.1Terminal testing configurationsTerminal type No. of devices Terminals to be wired on each deviceCombination wire-binding screw andpressure-wire terminal1 Two pressure-wire terminals wired usingConfiguration No. 1a1 Two pressure-wi
15、re terminals wired usingConfiguration No. 2a1 Two pressure-wire terminals wired usingConfiguration No. 3aaThe wiring configurations are shown in Figure 5.28.1.This is generated text for figtxt.(New) 5.28.3 Each terminal is to be wired with each conductor size and type as specified by themanufacturer
16、. The conductors shall be wired by applying the tightening torque as specified in Table 5.28.2to the terminal screw. The wire is to be stripped to the length specified in the manufacturers installationinstructions. Terminals are to be wired by placing the stripped conductor into the terminal. The co
17、nductoris to be positioned to follow any wire guides or other openings provided to align the conductor with theback of the switch housing. The terminal screw is to be tightened with a clutch-type torque screwdriverwhich has been calibrated and preset to release at the specified value. The switch sha
18、ll comply with121.1(a) upon completion of this procedure.(New) Figure 5.28.1Wiring configurations for combination wire binding/pressure-type terminalsSTANDARD NUMBER: UL 20 -3-UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL(New)Table 5.28.2Te
19、rminal screw tightening torqueScrew size Tightening torque pound-inches (Nm)No. 6 or less 12 (1.4)No. 8 or greater 14 (1.6)(New) 5.28.4 Each termination is then to be disassembled and the assembly and torqueing repeated onceusing newly stripped wire. The switch shall comply with 5.28.1 upon completi
20、on of this procedure.(New) 5.28.5 Following the last torqueing, each terminal is to be subjected to a straight 20-lbf (89-N) pullapplied to each wire for 1 minute perpendicular to the plane of the back cover of the switch. The switchshall comply with 5.28.1 upon completion of this procedure.7 Markin
21、gs7.1 General(New) 7.1.10 A flush switch rated 20 A or less and employing a combination wire binding/pressure-typeterminal shall be provided with installation instructions for assembly of conductors to the terminals. TheseInstructions shall include a pictorial representation of the placement of the
22、stripped conductor within thechannels/guides of the body. The instructions shall be attached to the switch in such fashion that it cannotbe accidentally removed or torn free from the flush switch during shipment, distribution, or normalhandling. A blister package or an equivalent means of securing t
23、he installation instructions to the switchmay be used. Friction alone shall not be used for attaching the installation instructions to the flush switch.The installation instructions may appear on a stuffer sheet packaged with each individual switch or printedon its individual unit shipping carton.RA
24、TIONALE FOR DECISION:The above requirements are intended to document current practice for evaluating this new terminaldesign.Copyright 2013 Underwriters Laboratories Inc.UL, in performing its functions in accordance with its objectives, does not guarantee or warrant thecorrectness of Certification R
25、equirement 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 the standard. They do not represent formal interpretations of thestandard under Amer
26、ican 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 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 20 -4-
