1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL 635 Insulating Bushings STANDARD FOR SAFETYUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM ULUL COPYRIGHTED MATERIAL NOT AUTHORIZED FO
2、R FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL Standard for Safety for Insulating Bushings, UL 635 Third Edition, Dated March 8, 2012 Summary of Topics This revision of ANSI/UL 635 is being issued to reaffirm approval of the document as an American National Standard. No changes
3、 in requirements were involved as part of this revision. The requirements are substantially in accordance with Proposal(s) on this subject dated April 15, 2016. Text that has been changed in any manner or impacted by ULs electronic publishing system is marked with a vertical line in the margin. All
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8、tandard on the purchasers computer system. JUNE 24, 2016 UL 635 tr1UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL JUNE 24, 2016 UL 635 tr2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION W
9、ITHOUT PERMISSION FROM UL MARCH 8, 2012 (Title Page Reprinted: June 24, 2016) 1 UL 635 Standard for Insulating Bushings First Edition November, 1996 Second Edition October, 2001 Third Edition March 8, 2012 This ANSI/UL Standard for Safety consists of the Third Edition including revisions through Jun
10、e 24, 2016. The most recent designation of ANSI/UL 635 as a Reaffirmed American National Standard (ANS) occurred on June 24, 2016. ANSI approval for a standard does not include the Cover Page, Transmittal Pages, Title Page, or effective date information. Comments or proposals for revisions on any pa
11、rt of the Standard may be submitted to UL at any time. Proposals should be submitted via a Proposal Request in ULs On-Line Collaborative Standards Development System (CSDS) at http:/. ULs Standards for Safety are copyrighted by UL. Neither a printed nor electronic copy of a Standard should be altere
12、d in any way. All of ULs Standards and all copyrights, ownerships, and rights regarding those Standards shall remain the sole and exclusive property of UL. COPYRIGHT 2016 UNDERWRITERS LABORATORIES INC. ANSI/UL 635-2012 (R2016)UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIB
13、UTION WITHOUT PERMISSION FROM UL MARCH 8, 2012 INSULATING BUSHINGS - UL 635 2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL CONTENTS INTRODUCTION 1 Scope .4 2 Units of Measurement .5 3 Undated References 5 4 Glossary .5
14、 CONSTRUCTION 5 General 6 6 Materials .6 6.1 General 6 6.2 Flammability .7 6.3 Temperature rating .7 6.4 Substitution of materials .7 6.5 Molding considerations 8 7 Accessories for Insulating Bushings 9 8 Corrosion Protection 9 PERFORMANCE 9 General 9 10 Feed-Through Test .10 11 Strain-Relief Test 1
15、0 12 Sharp Bend Protection Test 12 MARKINGS 13 Details .14 MARCH 8, 2012 INSULATING BUSHINGS - UL 635 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL INTRODUCTION 1 Scope 1.1 This Standard covers insulating bushings and accessories for insu
16、lating bushings used for the following purposes in electrical equipment: a) Insulating bushings used for the protection of cables, exible cords, and insulated wires, where routed through internal or external walls of electrical equipment. b) Insulating bushings used to provide strain-relief for exib
17、le cord and single conductor insulated wiring and to protect such cords or wiring. c) Accessories to insulating bushings used to supplement the characteristics of the bushing. 1.2 This Standard does not cover bushings used in the following applications: a) Bushings for the protection of uninsulated
18、conductors. b) Strain-relief insulating bushings used to hold more than one cable, wire, or cord. c) Bushings that are an integral part of a exible cord. d) Bushings used at the end of a raceway at the point of connection to open wiring and bushings used in conjunction with rigid or exible conduit,
19、conduit ttings, electrical metallic tubing, armored cable, or non-metallic sheathed cable. e) Bushings for power circuit breakers, transformers, or similar power apparatus rated more than 600 volts. f) Bushings intended for outdoor use. g) Bushings used on armored cable between the conductors and th
20、e outer armor. h) Insulating bushings provided either separately or as part of a conduit tting. i) Rainproof or liquid tight bushings. j) Bushings for use on the ends of rigid or exible conduit. k) Closures of the type used to plug holes in outlet boxes or outlet box covers: 1) Covered by the Standa
21、rd for Metallic Outlet Boxes, UL 514A and by the Standard for Nonmetallic Outlet Boxes, Flush-Device Boxes, and Covers, UL 514C; or 2) Of the type used to plug holes in enclosures. l) The following items covered by the Standard for Conduit, Tubing, and Cable Fittings, UL 514B: 1) Cord grips; 2) Insu
22、lating bushings; MARCH 8, 2012 INSULATING BUSHINGS - UL 635 4UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 3) Liquid-tight exible cord ttings; 4) Mesh grips; 5) Strain relief grips; 6) Strain relief grips for bus drop cables; 7) Strain rel
23、ief grips for exible cords; and 8) Strain relief with wire mesh cord grips. 1.3 In this standard, a requirement which applies to one type of bushing is to be identied by a specic reference in that requirement to the type of bushing involved. In the absence of such specic reference or when the genera
24、l terms bushing or insulating bushing are used, it is to be understood that the requirement applies to all other types of bushings covered by this standard. 2 Units of Measurement 2.1 Values stated without parentheses are the requirement. Values in parentheses are explanatory or approximate informat
25、ion. 3 Undated References 3.1 Any undated reference to a code or standard appearing in the requirements of this standard shall be interpreted as referring to the latest edition of that code or standard. 4 Glossary 4.1 For the purpose of this standard the following denitions apply. 4.2 CORD GUARD A c
26、ord guard is an accessory device used to provide a smooth bend of the cord exiting from a bushing. 4.3 INSULATING BUSHING ACCESSORY A subordinate part of an assembly used to complete the function of a bushing. 4.4 INSULATING FEED-THROUGH BUSHING A device which physically and electrically separates c
27、ables, exible cord, or insulated wires from metal edges of openings through which they pass. A feed- through bushing is not intended to provide any strain relief. 4.5 INSULATING STRAIN-RELIEF BUSHING A device which physically and electrically separates cables, exible cord, or insulated wires from me
28、tal edges of openings through which they pass and prevents a mechanical force (push, pull) imposed on the conductors from being transmitted to internal electrical connections through the plane of the bushing opening. MARCH 8, 2012 INSULATING BUSHINGS - UL 635 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED
29、FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL CONSTRUCTION 5 General 5.1 A bushing shall be constructed so that it has the strength and rigidity required to resist the abuses to which it is subjected, without increasing the re, shock or casualty hazards due to total or partial
30、collapse with resulting reduction in spacings, loosening or displacement of parts, or other serious defects. 5.2 A bushing shall be provided with a means to reliably secure it in place. 5.3 The surfaces against which the cable, exible cord or insulated wire bear shall be smooth and rounded. 5.4 A st
31、rain-relief bushing shall be constructed so that it performs its intended function without damage to the exible cord or insulated wire. An anti-rotation feature shall be provided. See 13.4(d). 5.5 A bushing that is intended to be used with a cord that is in motion during normal use shall provide sha
32、rp bend protection as indicated in the Sharp Bend Protection Test, Section 12. 6 Materials 6.1 General 6.1.1 Ceramic materials and some molded compositions such as phenolic and urea formaldehyde are capable of being used as materials for a separate insulating bushing. Vulcanized ber is not prohibite
33、d from being used when the bushing is not less than 3/64 inch (1.2 mm) thick, and when it is formed and secured in place so that it is not adversely affected by conditions of typical moisture. Other materials, such as nylon, are capable of being used after a suitable investigation. 6.1.2 Wood, hot-m
34、olded shellac, tar compositions, or rubber shall not to be used as materials for a separate insulating bushing. 6.1.3 The wall thickness of an insulating bushing shall not be less than 3/64 inch (1.2 mm) unless a thickness has been determined to be capable of being used as a result of an investigati
35、on. See reference to vulcanized ber in 6.1.1. This requirement does not preclude the use of narrow slots or openings in the wall of an insulating bushing when the intended cable, exible cord, or insulated wire is not capable of being pressed into such slots or openings. MARCH 8, 2012 INSULATING BUSH
36、INGS - UL 635 6UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 6.2 Flammability 6.2.1 Materials employed in the construction of insulating bushings shall be classied with a ammability rating of at least HB as determined by the Standard for T
37、ests for Flammability of Plastic Materials for Parts in Devices and Appliances, UL 94 or IEC 60695-11-10, Test Flames 50 W Horizontal and Vertical Flame Test Methods. 6.3 Temperature rating 6.3.1 The temperature rating of a bushing is to be based on the mechanical-without-impact relative thermal ind
38、ex (RTI Strength) of the material used in the insulating bushing. The relative thermal index shall be determined in accordance with the Standard for Polymeric Materials Long Term Property Evaluations, UL 746B. Note: The relative thermal index of a material is an indication of the materials ability t
39、o retain a particular property (such as physical or electrical) when exposed to an elevated temperature for an extended period of time. For each material, a number of relative thermal indices are established, each related to a specic property, and specic thickness of the material. 6.3.2 The temperat
40、ure rating of an insulating bushing shall not exceed the mechanical-without-impact relative thermal index of the material that is selected for the insulating bushing device, in the bushings minimum critical thickness. When a bushing model number is evaluated with alternate or substitute materials (s
41、ee Substitution of materials, Section 6.4) the temperature rating for that specic model number can not exceed the lowest mechanical-without-impact relative thermal index of the materials authorized for that model. 6.4 Substitution of materials 6.4.1 Another polymeric material shall be allowed to be
42、substituted in a device having met the requirements of this Standard only when all of the following conditions are met and compliance is determined through an appropriate investigation: a) The substitute material has an identical generic description (for example: Type 66, 30 percent glass lled, FR t
43、ype, polyamide). b) The tensile strength of the substitute and the originally evaluated material, determined in accordance with the Standard for Polymeric Materials Short Term Property Evaluations, UL 746A or ISO 527-1, Plastics Determination of Tensile Properties Part 1: General Principles, and ISO
44、 527-2, Plastics Determination of Tensile Properties Part 2: Test Conditions for Moulding and Extrusion Plastics, shall be compared, and shall indicate that the substitute material has a strength of at least 95 percent of that of the original material. The tensile strengths used in this comparison s
45、hall be generated by either: 1) A previous investigation or 2) Side-by-side testing of both materials. c) The substitute materials mechanical-without-impact relative thermal index shall be equal to or higher than the originally evaluated material. MARCH 8, 2012 INSULATING BUSHINGS - UL 635 7UL COPYR
46、IGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 6.5 Molding considerations 6.5.1 Except as indicated in (a) and (b), polymeric materials used to mold or fabricate devices covered by this Standard shall be made from materials that are 100 percent vir
47、gin and unmodied by the molder: a) Devices made from thermoplastic materials are limited to 25 percent regrind by weight of the same material, unless the results of a separate investigation indicate acceptable performance for the material or the specic device. The Standard for Polymeric Materials Fa
48、bricated Parts, UL 746D, includes guidelines to be considered in such a separate investigation. b) Devices covered by this Standard shall be allowed to employ colorants, ame retardants, llers, mold-release lubricants, color concentrates, dyestuff, chemical blowing agents or reinforcements in conjunc
49、tion with the polymeric material, when the additive or concentrate is tested and found not to adversely affect the critical properties of the material. An additive or concentrate of unknown performance shall not be used. The Standard for Polymeric Materials Fabricated Parts, UL 746D, provides guidance for the use of specic additives that may be used in the molding process without need for separate investigation. 6.5.2 Devices shall not employ materials that have been
