1、UL 1434ISBN 0-7629-294-9Thermistor-Type DevicesUnderwriters Laboratories Inc. (UL)333 Pfingsten RoadNorthbrook, IL 60062-2096UL Standard for Safety for Thermistor-Type Devices, UL 1434First Edition, Dated April 3, 1998Revisions: This Standard contains revisions through and including August 30, 2002U
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20、n effect, except for those paragraphs, sections, tables, figures,and/or other elements of the Standard having future effective dates as indicated in the note following theaffected item. The prior text for requirements that have been revised and that have a future effective dateare located after the
21、Standard, and are preceded by a SUPERSEDED REQUIREMENTS notice.New product submittals made prior to a specified future effective date will be judged under all of therequirements in this Standard including those requirements with a specified future effective date, unlessthe applicant specifically req
22、uests that the product be judged under the current requirements. However, ifthe applicant elects this option, it should be noted that compliance with all the requirements in thisStandard will be required as a condition of continued Recognition, and Follow-Up Services after theeffective date, and und
23、erstanding of this should be signified in writing.Copyright 2002 Underwriters Laboratories Inc.AUGUST 30, 2002 UL 1434tr2This Standard consists of pages dated as shown in the following checklist:Page Date1-5 .August 30, 20026December 15, 20007-10 August 30, 200211.December 15, 200012-13 .August 30,
24、200214 .April 3, 199815-18 December 15, 200019August 30, 200220-21 December 15, 200022-24BAugust 30, 200225 .April 3, 199826.December 15, 200027August 30, 200228 .April 3, 199829-30 December 15, 200031-33 .August 30, 200234-35 December 15, 200036-37 .August 30, 200238 .April 3, 1998A1-A2 April 3, 19
25、98AUGUST 30, 2002 UL 1434 tr3AUGUST 30, 2002 UL 1434tr4No Text on This PageAPRIL 3, 1998(Title Page Reprinted: August 30, 2002)1UL 1434Standard for Thermistor-Type DevicesFirst EditionApril 3, 1998An effective date included as a note immediately following certain requirementsis one established by Un
26、derwriters Laboratories Inc.Revisions of this Standard will be made by issuing revised or additional pagesbearing their date of issue. A UL Standard is current only if it incorporates themost recently adopted revisions, all of which are itemized on the transmittal noticethat accompanies the latest s
27、et of revised requirements.ISBN 0-7629-294-9COPYRIGHT 2000, 2002 UNDERWRITERS LABORATORIES INC.AUGUST 30, 2002THERMISTOR-TYPE DEVICES - UL 14342No Text on This PageCONTENTSFOREWORD 4INTRODUCTION1 Scope .52 General 62.1 Components .62.2 Undated references .62.3 Units of measurement .73 Glossary .7CON
28、STRUCTION4 General .12B5 Protection Against Corrosion .12B6 Insulating Material .137 Spacings 137.1 Line-voltage circuits 137.2 Low-voltage and isolated-limited-energy secondary circuits .158 Alternative Spacings Clearances and Creepage Distances 169 Live Parts .17PERFORMANCE PTC THERMISTORS10 Gener
29、al 1711 Calibration Tests 1911.1 General .1911.2 R/T measurement for PTC thermistors - all types 2011.3 R/T measurement for PTC heaters .2111.4 Hold current (Ih) test for PTC current limiters 2111.5 Time-to-trip test for PTC current limiters .2211.6 Surface temperature test .2212 Aging Test .2313 He
30、at-Cold-Humidity Cycling Test .2414 Overload Test .24A15 Endurance Test .24A16 Cold Operational Cycling Test 24B17 Cold Thermal Cycling Test .24B18 Limited Short-Circuit Test 2518.1 General .2518.2 Primary circuit applications 2518.3 Other than primary circuit applications 2719 Thermal Runaway Test
31、2720 Dielectric Voltage-Withstand Test (For Insulated Thermistors Only) .27AUGUST 30, 2002 THERMISTOR-TYPE DEVICES - UL 1434 2APERFORMANCE NTC THERMISTORS21 General 2822 Calibration Tests 2922.1 General .2922.2 R/T measurement for NTC thermistors 3022.3 Surface temperature test (inrush-current limit
32、ing only) 3122.4 Resistance (R25) and beta value (B) test for NTC thermistors 3123 Aging Test .3224 Heat-Cold-Humidity Cycling Test .3225 Overload Test 3426 Endurance Test 3427 Cold Operational Cycling Test 3528 Cold Thermal Cycling Test .3629 Dielectric Voltage-Withstand Test (For Insulated Thermis
33、tors Only) .36MANUFACTURING AND PRODUCTION TESTS30 General 36RATING31 General 36AMARKING32 General 38APPENDIX AStandards for ComponentsA1AUGUST 30, 2002THERMISTOR-TYPE DEVICES - UL 14342BAUGUST 30, 2002 THERMISTOR-TYPE DEVICES - UL 1434 3No Text on This PageFOREWORDA. This Standard contains basic re
34、quirements for products covered by Underwriters Laboratories Inc. (UL)under its Follow-Up Service for this category within the limitations given below and in the Scope sectionof this Standard. These requirements are based upon sound engineering principles, research, records oftests and field experie
35、nce, and an appreciation of the problems of manufacture, installation, and usederived from consultation with and information obtained from manufacturers, users, inspection authorities,and others having specialized experience. They are subject to revision as further experience andinvestigation may sh
36、ow is necessary or desirable.B. The observance of the requirements of this Standard by a manufacturer is one of the conditions of thecontinued coverage of the manufacturers product.C. A product which complies with the text of this Standard will not necessarily be judged to comply withthe Standard if
37、, when examined and tested, it is found to have other features which impair the level ofsafety contemplated by these requirements.D. A product that contains features, characteristics, components, materials, or systems new or differentfrom those covered by the requirements in this standard, and that
38、involves a risk of fire or of electric shockor injury to persons shall be evaluated using appropriate additional component and end-productrequirements to maintain the level of safety as originally anticipated by the intent of this standard. Aproduct whose features, characteristics, components, mater
39、ials, or systems conflict with specificrequirements or provisions of this standard does not comply with this standard. Revision of requirementsshall be proposed and adopted in conformance with the methods employed for development, revision, andimplementation of this standard.E. UL, in performing its
40、 functions in accordance with its objectives, does not assume or undertake todischarge any responsibility of the manufacturer or any other party. The opinions and findings of ULrepresent its professional judgment given with due consideration to the necessary limitations of practicaloperation and sta
41、te of the art at the time the Standard is processed. UL shall not be responsible to anyonefor the use of or reliance upon this Standard by anyone. UL shall not incur any obligation or liability fordamages, including consequential damages, arising out of or in connection with the use, interpretation
42、of,or reliance upon this Standard.F. Many tests required by the Standards of UL are inherently hazardous and adequate safeguards forpersonnel and property shall be employed in conducting such tests.AUGUST 30, 2002THERMISTOR-TYPE DEVICES - UL 14344INTRODUCTION1 Scope1.1 These requirements apply to di
43、screte thermistor-type devices constructed of ceramic or polymericsemiconductor material.1.1 effective April 3, 20001.2 These thermistors are intended for use as:a) Self-limiting devices such as heaters;b) Control devices such as current limiters and inrush-current limiters; orc) Sensing devices.1.2
44、 effective April 3, 20001.3 These requirements apply to positive temperature coefficient (PTC) and negative temperaturecoefficient (NTC) type devices.1.3 effective April 3, 20001.4 Control devices, such as current limiters are not intended to replace current interrupting devices suchas fuses, but ar
45、e intended to provide a level of overcurrent protection complying with the end-useequipment requirements.1.4 effective April 3, 20001.5 These requirements do not apply to heating cables, such as self-regulating pipe heating cable, thatare constructed with thermistor-type material.1.5 effective April
46、 3, 20001.6 Deleted August 30, 2002AUGUST 30, 2002 THERMISTOR-TYPE DEVICES - UL 1434 52 General2.1 Components2.1.1 Except as indicated in 2.1.2, a component of a product covered by this standard shall comply withthe requirements for that component. See Appendix A for a list of standards covering com
47、ponents usedin the products covered by this standard.2.1.1 effective April 3, 20002.1.2 A component is not required to comply with a specific requirement that:a) Involves a feature or characteristic not required in the application of the component in theproduct covered by this standard, orb) Is supe
48、rseded by a requirement in this standard.2.1.2 revised December 15, 20002.1.3 A component shall be used in accordance with its rating established for the intended conditions ofuse.2.1.3 effective April 3, 20002.1.4 Specific components are incomplete in construction features or restricted in performa
49、ncecapabilities. Such components are intended for use only under limited conditions, such as certaintemperatures not exceeding specified limits, and shall be used only under those specific conditions.2.1.4 effective April 3, 20002.1.5 Deleted December 15, 20002.1.6 Deleted December 15, 20002.1.7 Deleted December 15, 20002.2 Undated references2.2.1 Any undated reference to a code or standard appearing in the requirements of this standard shallbe interpreted as referring to the latest edition of that code or standard.2.2.1 effective April 3, 2000DECEMBER 15, 2
