1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL 746C Polymeric Materials - Use in Electrical Equipment EvaluationsUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM ULUL COPYRIGHTED MAT
2、ERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL Standard for Safety for Polymeric Materials Use in Electrical Equipment Evaluations, UL 746C Sixth Edition, Dated September 10, 2004 SUMMARY OF TOPICS These revisions to ANSI/UL 746C include the following cha
3、nges in requirements: Deletion of the Twin Carbon Arc Equipment for UV Testing The revised requirements are substantially in accordance with Proposal(s) on this subject dated April 10, 2015. Text that has been changed in any manner or impacted by ULs electronic publishing system is marked with a ver
4、tical line in the margin. Changes in requirements are marked with a vertical line in the margin and are followed by an effective date note indicating the date of publication or the date on which the changed requirement becomes effective. All rights reserved. No part of this publication may be reprod
5、uced, stored in a retrieval system, or transmitted in any form by any means, electronic, mechanical photocopying, recording, or otherwise without prior permission of UL. UL provides this Standard as is without warranty of any kind, either expressed or implied, including but not limited to, the impli
6、ed warranties of merchantability or tness for any purpose. In no event will UL be liable for any special, incidental, consequential, indirect or similar damages, including loss of prots, lost savings, loss of data, or any other damages arising out of the use of or the inability to use this Standard,
7、 even if UL or an authorized UL representative has been advised of the possibility of such damage. In no event shall ULs liability for any damage ever exceed the price paid for this Standard, regardless of the form of the claim. Users of the electronic versions of ULs Standards for Safety agree to d
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9、s in this Standard are now in effect, except for those paragraphs, sections, tables, gures, and/or other elements of the Standard having future effective dates as indicated in the note following the affected item. The prior text for requirements that have been revised and that have a future effectiv
10、e date are located after the Standard, and are preceded by a SUPERSEDED REQUIREMENTS notice. JUNE 23, 2015 UL 746C tr1UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL JUNE 23, 2015 UL 746C tr2 No Text on This PageUL COPYRIGHTED MATERIAL NOT A
11、UTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL SEPTEMBER 10, 2004 (Title Page Reprinted: June 23, 2015) 1 UL 746C Standard for Polymeric Materials Use in Electrical Equipment Evaluations The rst edition was titled Test for Polymeric Enclosures of Portable Electrical Ap
12、pliances and numbered UL 746.51. First Edition June, 1973 Second Edition March, 1978 Third Edition May, 1989 Fourth Edition December, 1995 Fifth Edition November, 2001 Sixth Edition September 10, 2004 This ANSI/UL Standard for Safety consists of the Sixth Edition including revisions through June 23,
13、 2015. The most recent designation of ANSI/UL 746C as an American National Standard (ANSI) occurred on June 22, 2015. 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 part of the Sta
14、ndard 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 altered in any way.
15、 All of ULs Standards and all copyrights, ownerships, and rights regarding those Standards shall remain the sole and exclusive property of UL. COPYRIGHT 2015 UNDERWRITERS LABORATORIES INC. ANSI/UL 746C-2015UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMIS
16、SION FROM UL MARCH 7, 2012 UL 746C 2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL CONTENTS INTRODUCTION 1 Scope .7 2 General 7 3 Glossary .9 ENCLOSURES 4 General .13 5 Portable Unattended Household Equipment Alternate
17、Path 14 5.1 General 14 5.2 Electrical connections 15 5.3 Materials adjacent to connections .16 5.4 Wire, tubing, sleeving and tape .16 ELECTRICAL INSULATION 6 Material Property Considerations 16 6.1 General 16 6.2 Evaluation of Materials Not Meeting Preselection Test Performance Levels in Table 6.1
18、.17 7 Internal Barriers .23 PERFORMANCE CRITERIA 8 General .24 ELECTRICAL 9 Comparative Tracking Index (CTI) .24 10 Dielectric Strength 25 11 High Current Arc Resistance to Ignition (HAI) 25 12 Hot-Wire Ignition (HWI) Abnormal Overload Test or Glow-Wire End-Product Test .26 12.1 General .26 12.2 Abn
19、ormal overload test .26 12.3 Glow-wire end-product test (GWEPT) .26A 13 Inclined Plane Tracking 27 14 Volume Resistivity 27 FLAMMABILITY 15 Flammability 12 mm Flame .28 16 Flammability 20 mm (3/4-Inch) Flame .28 17 Flammability 127 mm (5 Inch) Flame 28 18 Enclosure Flammability 746-5VS 29 18.1 Test
20、criteria 29 19 Enclosure Flammability Large Surface Area Considerations 29 20 Flame-Retardant Coatings .30 20.1 General .30 20.2 Test criteria 31 MARCH 7, 2012 UL 746C 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL MECHANICAL 21 Crushing R
21、esistance 31 22 Resistance to Impact 31 DIMENSIONAL CHANGE OF POLYMERIC PARTS 23 Creep .32 PERMANENCE 24 Permanence .33 24.1 General .33 24.2 Vicat softening point 33 24.3 Heat deection temperature .33 24.4 Ball pressure temperature .33 25 Ultraviolet Light Exposure 33 26 Water Exposure and Immersio
22、n 34 26.1 General .34 26.2 Dimensional change 35 SPECIAL END-USE CONSIDERATIONS 27 Abnormal Operation .35 28 Severe Conditions 35 THERMAL 29 Mold Stress-Relief Distortion .35 30 Input to Motor 36 31 Strain-Relief Test after Mold Stress-Relief Distortion 36 32 Temperature Considerations General 36 33
23、 Functional-Use Temperature Indices 37 34 Generic Thermal Indices .38 35 Relative Thermal Index 39 36 Relative Thermal Capability 41 37 Relative Thermal Capability (Alternate) 42 38 Temperature Excursions Beyond the Maximum Use Temperature 46 SPECIALIZED APPLICATIONS 39 General Adhesives 47 40 Funct
24、ion Analysis .47 41 Program of Investigation .47 41.1 End-product evaluation .47 41.2 Effect of environmental conditions 47 42 Coil Forms .48 43 Conformal Coatings .48 43A Conformal Coatings 48 APRIL 6, 2010 UL 746C 4UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WIT
25、HOUT PERMISSION FROM UL METALLIZED PARTS 44 General 49 45 Ductile Coatings 49 46 Brittle Coatings .50 TEST PERFORMANCE 47 General 50 47.1 Details 50 47.2 Voltmeters .50 47.3 Cheesecloth indicators 51 47.4 Supply-circuit voltage and frequency 51 48 End-Product Arc Resistance Test .51 49 Abnormal Over
26、load Test .52 50 Flammability 12 mm Flame Test 54 51 Flammability 20 mm (3/4 Inch) Flame Test .55 52 Flammability 127 mm (5 inch) Flame Test .56 53 Enclosure Flammability 746-5VS Test .58 53.1 Apparatus .58 53.2 Plaque conditioning .59 54 Flame-Retardant Coatings Test .60 54.1 Specimen conditioning
27、60 54.2 Test methods 62 54.3 Other considerations 62 55 Crushing Resistance Test 63 56 Resistance to Impact Test .63 57 Ultraviolet Light Exposure Test 66A 57.1 Apparatus 66A 57.2 Method 66A 58 Water Exposure and Immersion Test 70 59 Abnormal Operation Test 74 60 Severe Conditions Test 74 61 Mold St
28、ress-Relief Distortion Test .75 62 Ball Pressure Test on End-Product .75 63 Input to Motors Test .76 64 Relative Thermal Capability 76 65 Relative Thermal Capability (Alternate) 77 66 Temperature Excursions Beyond the Maximum Use Temperature 77 67 Temperature Considerations Illustrative Example .79
29、68 Temperature Considerations Illustrative Example (Alternate RTC) .80 69 Adhesives Specialized Applications .84 69.1 General .84 69.2 As-received test 84 69.3 Effect of temperature .84 69.4 Effect of humidity .86 69.5 Effect of cold 86 69.6 Effect of cyclic conditions 86 69.7 Other test considerati
30、ons 93 FEBRUARY 20, 2006 UL 746C 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL COIL FORMS 70 Conformal Coating Test .93 70A Conformal Coating Test 93 71 Tape Adhesion Test .94 71.1 General .94 71.2 Samples 94 71.3 Coating Thickness Measur
31、ement .94A 71.4 Sample Preparation .94A 71.5 Conditioning .95 71.6 Results .95 72 Leakage Current Test .96 73 Glow-Wire End-Product Test .99 73.1 General .99 73.2 Signicance .99 73.3 Apparatus Deleted March 7, 2012 99 73.4 Specimens Deleted March 7, 2012 .99 73.5 Conditioning Deleted March 7, 2012 9
32、9 73.6 Procedure Deleted March 7, 2012 99 MARKING 74 General 102 APPENDIX A Guidelines for Evaluation of Substitute Polymeric Materials A1 Alternate Enclosure Material Considerations .A1 FEBRUARY 6, 2013 UL 746C 6UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT
33、 PERMISSION FROM UL INTRODUCTION 1 Scope 1.1 These requirements cover parts made of polymeric materials that are used in electrical equipment and describe the various test procedures and their use in the testing of such parts and equipment. 1.2 These requirements do not cover the specic insulating s
34、ystems that are covered by the requirements contained in the Standard for Systems of Insulating Materials, General, UL 1446. 1.3 Test procedures are provided herein for the evaluation of polymeric materials in specic applications. These test procedures include references to data obtained from small-
35、scale property tests conducted under standard conditions as well as other practical means of evaluation. 2 General 2.1 If a value for measurement is followed by a value in other units, the use of either value can be expected to provide equivalent results in the application of such requirements. Each
36、 of the requirements is stated in SI units as well as in U.S. customary units. Equivalent, although not necessarily exactly identical results, are to be expected from applying a requirement in SI units or U.S. customary units. Equipment calibrated in metric units is to be used when a requirement is
37、applied in metric terms. 2.2 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. 2.3 For reference purposes, Figure 2.1 describes the procedure to be followed in the evaluation of
38、 parts made of polymeric materials and covered by the requirements in this standard. 2.4 The Standard for Tests for Flammability of Plastic Materials for Parts in Devices and Appliances, UL 94, covers ammability of polymeric materials used for parts in devices and appliances. The Standard for Polyme
39、ric Materials Short Term Property Evaluations, UL 746A, contains short-term test procedures to be used for the evaluation of materials used for parts intended for specic applications in electrical end- products. The Standard for Polymeric Materials Long Term Property Evaluations, UL 746B, contains l
40、ong-term test procedures to be used for the evaluation of materials used for parts intended for specic applications in end-products. The Standard for Polymeric Materials Fabricated Parts, UL 746D, contains requirements for traceability and performance of parts molded and fabricated from polymeric ma
41、terials. 2.5 Requirements for materials that have been modied to match the requirements of a specic application, including the use of recycled and regrind materials, the use of additives and colorants, and the blending of two or more materials, are described in the Standard for Polymeric Materials F
42、abricated Parts, UL 746D. SEPTEMBER 10, 2004 UL 746C 7UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL Figure 2.1 UL 746C guide for polymeric evaluations SEPTEMBER 10, 2004 UL 746C 8UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCT
43、ION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 3 Glossary 3.1 For the purposes of this standard the following denitions apply: 3.2 ACCESSIBLE PART A part so located that it can be contacted by a person, either directly or by means of a probe or a tool, or that is not recessed the required distance b
44、ehind an opening. 3.3 ATTENDED EQUIPMENT Equipment intended for use where operator presence is required for the equipment to function but is not necessarily required for the equipment to operate. Operator absence is effectively limited to short durations due to one or more characteristics of the equ
45、ipment such as production of excessive noise or vibration. Examples may include hand-held drills, electric knives, can openers, hand-held hair dryers, blenders, and vacuum cleaners. 3.4 BRANCH CIRCUIT A branch circuit is that portion of the building wiring system beyond the nal overcurrent device on
46、 the power- distribution panel protecting the circuit to the eld-wiring terminals of permanently connected equipment or to the receptacle outlet for cord-connected appliances. 3.5 COMPARATIVE TRACKING INDEX Comparative tracking index (CTI) is determined by the method described in the Standard for Po
47、lymeric Materials Short Term Property Evaluations, UL 746A, Recommended Method for Determining the Comparative Tracking Index of Solid Insulating Materials Under Moist Conditions. CTI range tracking index Assigned PLC (Volts) 600 TI 0 400 TI 600 1 250 TI 400 2 175 TI 250 3 100 TI 175 4 0 TI 100 5 3.
48、6 CONFORMAL COATING A protective covering applied on a printed wiring board to increase the dielectric voltage-withstand capability between conductors and to protect against environmental conditions. 3.7 CORD-CONNECTED UNIT An appliance or product intended for connection to the branch-circuit power
49、line by means of a power supply cord. 3.8 COUNTER-SUPPORTED APPLIANCE An appliance that is physically supported by a counter, table or bench during the performance of its intended function. 3.9 DECORATIVE PART A part used for ornamental purposes only and not as an enclosure or insulation of electrically live parts. 3.10 ENCLOSURE That part of the product that: a) Renders inaccessible all or any parts of the equipment that may
