1、 International Telecommunication Union ITU-T K.82TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (05/2010) SERIES K: PROTECTION AGAINST INTERFERENCE Characteristics and ratings of solid-state, self-restoring overcurrent protectors for the protection of telecommunications installations Recommendation
2、 ITU-T K.82 Rec. ITU-T K.82 (05/2010) i Recommendation ITU-T K.82 Characteristics and ratings of solid-state, self-restoring overcurrent protectors for the protection of telecommunications installations Summary Recommendation ITU-T K.82 defines the basic requirements and parameters of solid-state, s
3、elf-restoring overcurrent protectors (OCPs) for the protection of telecommunication installations (for example, exchange equipment, access equipment, telecommunication lines and subscriber or customer equipment). This Recommendation should be used for the harmonization of existing or future specific
4、ations issued by solid-state, self-restoring overcurrent protector manufacturers, telecommunication equipment manufacturers, administrations or network operators. History Edition Recommendation Approval Study Group 1.0 ITU-T K.82 2010-05-29 5 Keywords CPTC, ECL, overcurrent protection, PPTC, PTC, se
5、lf-restoring, surge protective component, surge protective device, thermistor. ii Rec. ITU-T K.82 (05/2010) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU
6、 Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardiza
7、tion Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. In some areas of information techn
8、ology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Complian
9、ce with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words “shall“ or some other oblig
10、atory language such as “must“ and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practice or implementatio
11、n of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. As of
12、the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to
13、consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2010 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T K.82 (05/2010) iii CONTENTS Page 1 Scope 1 2 References. 1 3 Definitions 3 3.
14、1 Terms defined elsewhere 3 3.2 Terms defined in this Recommendation . 3 4 Abbreviations, acronyms and symbols . 4 5 Storage conditions 5 6 Electrical requirements . 5 6.1 resistance, R 5 6.2 hold current, Ih5 6.3 trip current, It5 6.4 time-to-trip, ttrip. 6 6.5 resistance 1 h after tripping, R1for
15、polymer PTC thermistors . 7 6.6 reset voltage, Vresetfor ECL 7 6.7 impulse resistance, Rimpfor ceramic PTC thermistors . 8 6.8 Impulse voltage withstand 8 6.9 AC power fault . 8 6.10 Impulse endurance test (life test) 9 6.11 AC endurance test (PTC thermistor) (life test) . 9 7 Test methods . 9 7.1 r
16、esistance, R 10 7.2 hold current, Ih10 7.3 trip current, It10 7.4 time-to-trip, ttrip. 11 7.5 resistance 1 h after tripping, R1, for polymer PTC thermistor 12 7.6 reset voltage, Vresetfor ECL 12 7.7 impulse resistance, Rimpat Vimpfor ceramic PTC thermistors 12 7.8 Impulse voltage withstand 13 7.9 AC
17、 power fault tests . 14 7.10 Impulse endurance test (life test) 14 7.11 AC endurance test (life test) . 14 8 Environment tests . 14 8.1 Robustness of terminations . 14 8.2 Solderability . 15 8.3 Resistance to soldering heat . 16 8.4 Vibration . 16 8.5 Bump 16 iv Rec. ITU-T K.82 (05/2010) Page 8.6 Ra
18、pid changes of temperature 17 8.7 Climatic sequence . 17 8.8 Damp heat, steady state 17 8.9 Fire hazard 17 8.10 Solvent resistance of marking 18 8.11 Component solvent resistance 18 9 Informative characteristics 18 9.1 Hold current variation with temperature 18 9.2 Trip-time variation with fault cur
19、rent value for PTC thermistor OCPs . 18 9.3 Resistance recovery after a trip event for PPTC thermistor OCPs . 19 10 Identification . 19 10.1 Marking 19 10.2 Documentation . 20 11 Ordering information 20 Bibliography. 21 Rec. ITU-T K.82 (05/2010) v Introduction Unlike fuses and heat coils, self-resto
20、ring overcurrent protectors (OCPs) automatically reset after the end of the overcurrent condition without the need for manual intervention, generally after power is removed at the end of the overcurrent. All the OCPs covered are solid-state. Having no moving parts, these OCPs are at least four times
21、 more reliable than thermal circuit breakers and six times more reliable than mechanical disk switches. The current reducing action is for the normally low (untripped) OCP resistance to transition to a very high tripped resistance value, which greatly reduces the circuit current flow. The positive t
22、emperature coefficient (PTC) thermistor OCPs transition is caused by the component body reaching a critical temperature. The body temperature rise is caused by the i2R heating of the overcurrent flowing through the component. Being thermally operated, PTC thermistor OCPs generally do not operate for
23、 short duration lightning currents, but will operate for AC overcurrents caused by power faults. Electronic current limiter (ECL) OCPs operate on a preset current threshold level and will reduce both AC and lightning overcurrents. Under lightning surge conditions, both OCP types assist in the coordi
24、nation function. Many of the performance tests and values can be applied to the three types of OCP technology. Some tests are specific to OCP used in SPDs (surge protective devices) or in equipment connected to an SPD and others to OCPs used in equipment. Differences between technologies mean that s
25、ome tests will be specific to a given technology. Rec. ITU-T K.82 (05/2010) 1 Recommendation ITU-T K.82 Characteristics and ratings of solid-state, self-restoring overcurrent protectors for the protection of telecommunications installations 1 Scope This Recommendation applies to 2-terminal, series c
26、onnected, solid-state, self-restoring overcurrent protectors (OCPs) used in surge protective devices (SPDs) and telecommunications equipment. These OCPs are directly connected to a device or equipment port and provide overcurrent protection and coordination functions for telecommunications installat
27、ions during lightning surges and AC power faults, in accordance with b-ITU-T K.11. The port test levels and criterion are defined by ITU-T K.20, ITU-T K.21 and ITU-T K.45, as appropriate. ITU-T K.44 supports these three equipment performance ITU-T Recommendations with test circuit details and applic
28、ation guidance. This Recommendation provides the basic requirements, and parameter tests, for OCPs used in the protection of telecom installations. This Recommendation covers the following types of solid-state, self-restoring OCP: a) polymer positive temperature coefficient (PPTC) thermistors; b) ce
29、ramic positive temperature coefficient (CPTC) thermistors; c) electronic current limiters (ECLs). It does not deal with: a) mountings and their effect on OCP performance, the test results only apply for the mounting method used for that test; b) system signal performance such as insertion loss, see
30、b-ITU-T G.117; c) mechanical dimensions; d) RoHS requirements; e) electrical overload; f) quality assurance requirements, see IEC 60738-1; g) specific cases of user agreed and regional values. 2 References The following ITU-T Recommendations and other references contain provisions which, through ref
31、erence in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the mos
32、t recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. ITU-T K.12 Recomm
33、endation ITU-T K.12 (2006), Characteristics of gas discharge tubes for the protection of telecommunications installations. ITU-T K.20 Recommendation ITU-T K.20 (2008), Resistibility of telecommunication equipment installed in a telecommunications centre to overvoltages and overcurrents. ITU-T K.21 R
34、ecommendation ITU-T K.21 (2008), Resistibility of telecommunication equipment installed in customer premises to overvoltages and overcurrents. 2 Rec. ITU-T K.82 (05/2010) ITU-T K.28 Recommendation ITU-T K.28 (1993), Characteristics of semi-conductor arrester assemblies for the protection of telecomm
35、unications installations. ITU-T K.44 Recommendation ITU-T K.44 (2008), Resistibility tests for telecommunication equipment exposed to overvoltages and overcurrents Basic Recommendation. ITU-T K.45 Recommendation ITU-T K.45 (2008), Resistibility of telecommunication equipment installed in the access
36、and trunk networks to overvoltages and overcurrents. IEC 60068-1 IEC 60068-1 (1988), Environmental testing Part 1: General and guidance, plus Amendment 1 (1992). IEC 60068-2-1 IEC 60068-2-1 (2007), Environmental testing Part 2-1: Tests Test A: Cold. IEC 60068-2-2 IEC 60068-2-2 (2007), Environmental
37、testing Part 2-2: Tests Test B: Dry heat. IEC 60068-2-6 IEC 60068-2-6 (2007), Environmental testing Part 2-6: Tests Test Fc: Vibration (sinusoidal). IEC 60068-2-13 IEC 60068-2-13 (1983), Environmental testing Part 2-13: Tests Test M: Low air pressure. IEC 60068-2-14 IEC 60068-2-14 (2009), Environmen
38、tal testing Part 2-14: Tests Test N: Change of temperature. IEC 60068-2-20 IEC 60068-2-20 (2008), Environmental testing Part 2-20: Tests Test T: Test methods for solderability and resistance to soldering heat of devices with leads. IEC 60068-2-21 IEC 60068-2-21 (2006), Environmental testing Part 2-2
39、1: Tests Test U: Robustness of terminations and integral mounting devices. IEC 60068-2-27 IEC 60068-2-27 (2008), Environmental testing Part 2-27: Tests Test Ea and guidance: Shock. IEC 60068-2-29 IEC 60068-2-29 (1987), Environmental testing Part 2: Tests Test Eb and guidance: Bump. IEC 60068-2-30 IE
40、C 60068-2-30 (2005), Environmental testing Part 2-30: Tests Test Db: Damp heat, cyclic (12 h+12 h cycle). IEC 60068-2-45 IEC 60068-2-45 (1980), Environmental testing Part 2-45: Tests Test XA and guidance: Immersion in cleaning solvents. IEC 60068-2-54 IEC 60068-2-54 (2006), Environmental testing Par
41、t 2-54: Tests Test Ta: Solderability testing of electronic components by the wetting balance method. IEC 60068-2-58 IEC 60068-2-58 (2004), Environmental testing Part 2-58: Tests Test Td: Test methods for solderability, resistance to dissolution of metallization and to soldering heat of surface mount
42、ing devices (SMD). IEC 60068-2-69 IEC 60068-2-69 (2007), Environmental testing Part 2-69: Tests Test Te: Solderability testing of electronic components for surface mounting devices (SMD) by the wetting balance method. IEC 60068-2-78 IEC 60068-2-78 (2001), Environmental testing Part 2-78: Tests Test
43、Cab: Damp heat, stead state. IEC 60695-11-5 IEC 60695-11-5 (2004), Fire hazard testing Part 11-5: Test flames Needle-flame test method Apparatus, confirmatory test arrangement and guidance. Rec. ITU-T K.82 (05/2010) 3 IEC 60738-1 IEC 60738-1 (2006), Thermistors Directly heated positive temperature c
44、oefficient Part 1: Generic specification. 3 Definitions 3.1 Terms defined elsewhere This Recommendation uses the following terms defined elsewhere: 3.1.1 fault current, Ifaultb-IEC 62319-1: Current used when measuring time-to-trip. 3.1.2 hold current, Ihb-IEC 62319-1: Maximum current at specified am
45、bient temperature, which will not cause the trip event. NOTE Sometimes known as rated or non-tripping current. 3.1.3 maximum current AC, Imax b-IEC 62319-1: Value of current for the operating temperature range, which should not be exceeded. 3.1.4 maximum voltage AC, Vmaxb-IEC 62319-1: Maximum AC vol
46、tage that may be applied. 3.1.5 positive temperature coefficient thermistor b-IEC 62319-1: Thermistor that exhibits a very sharp increase in resistance over a narrow temperature range. NOTE In this Recommendation, the change of temperature that results in resistance increase is caused by the current
47、 flow through the PTC thermistor. 3.1.6 resistance 1 h after tripping (polymer PTC thermistor), R1b-IEC 62319-1: Resistance of a Polymer PTC thermistor 1 h after a trip event or 1 h after reflow for surface mounting devices. NOTE R1maxis the maximum allowed value of R1. 3.1.7 time-to-trip, (PTC ther
48、mistor) ttripb-IEC 62319-1: Under specified ambient conditions, starting from the time the fault current (Ifault) is applied, the time-to-trip is the time required for a device to transition into a tripped state. NOTE An OCP shall have passed into the tripped condition as indicated by the measured v
49、oltage exceeding 90% of the supply open-circuit voltage. 3.1.8 trip current, It b-IEC 62319-1: Lowest current which will cause a trip event at a specified temperature and within a time specified in the product specification. 3.1.9 trip event b-IEC 62319-1: Event of rapid increasing resistance in response to an overcurrent surge. 3.2 Terms defined in this Recommendation This Recommendation defines the followi
