1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULMarch 6, 20081SUBJECT 2567OUTLINE OF INVESTIGATIONFORPART 3: LOW-VOLTAGE SURGE WITHSTAND TELECOMMUNICATIONSPOLYMER POSITIVE TEMPERATURE COEFFICIENT THERMISTOR (PPTC)ISSUE NO. 1March 6, 2008This f
2、irst issue of the Outline of Investigation for Low-Voltage SurgeWithstand Telecommunications Polymer Positive Temperature CoefficientThermistor (PPTC), Subject 2567, applies to Polymer Positive TemperatureCoefficient Thermistors PPTC for up to 600 Vac, 60 A limited durationcurrent interrupting capab
3、ility.The UL Foreword is no longer located within the UL Standard. For informationconcerning the use and application of the requirements contained in thisStandard, the current version of the UL Foreword is located onULStandardsInfoNet at: http:/ 2008 UNDERWRITERS LABORATORIES INC.UL COPYRIGHTED MATE
4、RIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULMARCH 6, 2008SUBJECT 25672No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULCONTENTS1.0 General 41.1 Scope .43.0 Service Environment Condit
5、ions .46.0 Marking 4MARCH 6, 2008 SUBJECT 2567 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL1.0 GeneralNote: This Part is intended to be read together with Low-Voltage Surge Withstand TelecommunicationsOvercurrent Protector Components Part
6、 1: General Requirements, hereafter referred to as Part 1. Thenumbering of the Clauses in this Part corresponds to like numbered Clauses in Part 1. The requirementsof Part 1 apply unless modified by this Part.1.1 ScopeThis Part applies to Polymer Positive Temperature Coefficient Thermistors PPTC for
7、 up to 600 Vac,60A limited duration current interrupting capability.3.0 Service Environment Conditions3.1 The manufacturer may specify a minimum circuit resistance between the primary and secondary ifpresent overvoltage protectors required for the PTC to pass all of the relevant tests in this standa
8、rd.3.4.3 DC Resistance Part 1, subclause 3.4.3.3The results are considered acceptable if there is no change in the measured DC resistances of more than15 percent between the as-received condition and the temperature-cycled condition.6.0 MarkingIn lieu of the mark specified in 6.1(c), protectors cove
9、red by this part shall have an alpha-numeric markin the form:N1AN2WhereN1is the classification number from Part 1, clause 4.1.1.A is the letter of the template met could be a string of several letters, if more than one templateneeds to be identifiedN2is the Voltage Group number from Part 1, clause 4
10、.1.2.Example:A protector marked 1A2-3 is a protector for use in a controlled environment; which meets template A;which requires a 600 V primary protector.7.1.3 Arrangement of the DUTThe DUT shall be mounted in a temperature-conditioning environmental chamber. The method ofmounting the device is impo
11、rtant, as it affects the heat transfer from the device, and consequently thedevice performance. Devices may be surface-mount or leaded. There is no industry-standard mountingmethod for either type of device. The method of mounting the test objects shall be specified by themanufacturer.MARCH 6, 2008S
12、UBJECT 25674UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULFor leaded devices, the suggested default method of mounting is to use Kelvin test clips. Suggested testclips are Mueller model BU75K or equivalent for example, see Figure 3.1. The ma
13、nufacturer shallspecify the method of mounting.If the test boards are used, a drawing of the board design and the specifications for the board shall beavailable from the manufacturer. The board design and specifications should be based on those shown inPart 2, Figure 2.2. The current leads of the te
14、st board should either be connected to the test generatorwith 14 AWG wire soldered to the edge pads, or contacted by the current leads of the Kelvin clips.This is generated text for figtxt.Example of the use of Mueller model BU75K Kelvin clips for mounting a leaded device. The current leads to the Kelvin clips are 14AWG. The voltage leads can be any convenient AWG.Figure 3.1MARCH 6, 2008 SUBJECT 2567 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULMARCH 6, 2008SUBJECT 25676No Text on This Page
