1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULJuly 30, 20101SUBJECT 4248-18OUTLINE OF INVESTIGATIONFORFuseholders - Part 18: PhotovoltaicISSUE NO: 2July 30, 2010Summary of TopicsThis second issue of the Outline of Investigation for Fuseholde
2、rs - Part18: Photovoltaic, Subject 4248-18, is to revise 6.1.1.1 to include markingrequirmenets for fuseholders that include a wire-connector feature, andaddress non-user replaceable fuses.COPYRIGHT 2010 UNDERWRITERS LABORATORIES INC.UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR
3、DISTRIBUTION WITHOUT PERMISSION FROM ULJULY 30, 2010SUBJECT 4248-182No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULCONTENTS1 General 41.1 Scope 44 Classification .45 Characteristics 45.1 Summary of characteristics .45.1.3
4、Voltage and current rating 45.1.4 Withstand rating .46 Marking 46.1 Marking of fuseholders .47 Construction 58 Tests 58.1 General 58.1.1 Types of tests .58.4 Verification of temperature rise 58.4.3 Test method 58.4.4 Acceptability of test results 68.5 Verification of withstand rating 6JULY 30, 2010
5、SUBJECT 4248-18 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL1 GeneralThis Outline of Investigation is intended to be read together with the Standard for Fuseholders, - Part 1:General Requirements, UL 4248-1 hereafter referred to as Part 1
6、 The numbering of the Clauses in thisPart corresponds to like numbered Clauses in Part 1. The requirements of Part 1 apply unless modifiedby this Part. For Clauses not shown below, refer to the Standard for Fuseholders - Part 1: GeneralRequirements, NMX-J-009-4248-ANCE CSA C22.2 No. 4248.1 UL 4248-
7、1.1.1 Scope1.1.2 These requirements cover fuseholders intended for use with Photovoltaic Fuses as described intheOutline of Investigation for Low-Voltage Fuses - Fuses for Photovoltaic Systems, Subject 2579.4 Classification4.1 Photovoltaic fuseholders have a minimum short-circuit withstand rating of
8、 10,000 A. Higher withstandratings are permitted. Photovoltaic fuseholders are rated up to 1500 V dc.5 Characteristics5.1 Summary of characteristics5.1.3 Voltage and current rating5.1.3.1 Photovoltaic fuseholders shall be rated up to 1500 V dc. Preferred ratings are 600 V, 750 V, 1000V, 1250 V and 1
9、500 V.5.1.4 Withstand rating5.1.4.1 Photovoltaic fuseholders shall have a minimum short-circuit withstand rating of 10,000 A. Higherwithstand ratings are permitted.6 Marking6.1 Marking of fuseholders6.1.1.1 In addition to the requirements of Part 1, the fuseholder shall be marked:f) Use Photovoltaic
10、 Fuses;g) for panel mount and in-line fuseholders, line and load shall be marked, with the terminalrecessed furthest in the device designated as the line terminal; andh) DO NOT OPERATE UNDER LOAD or equivalent for fuseholders of the modular designwhere the fuse is inserted or removed by use of a car
11、rier.i) Do not connect or disconnect under load for fuseholders that include a wire connectorfeature.Exception: Fuseholders employing an integral, non-user replaceable fuse need not bear the markingsspecified in 6.1.1.1 f) and 6.1.1.1 g).JULY 30, 2010SUBJECT 4248-184UL COPYRIGHTED MATERIAL NOT AUTHO
12、RIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL7 Construction7.1 In addition to the requirements of Part 1, photovoltaic fuseholders that include a wire connectorfeature or are intended for unprotected outdoor use shall comply with the requirements of the Outline OfInvestiga
13、tion For Connectors For Use In Photovoltaic Systems, Subject 6703.8 Tests8.1 General8.1.1 Types of tests8.1.1.1.1 Each fuseholder shall be subjected to the tests as specified in Part 1.8.4 Verification of temperature rise8.4.3 Test method8.4.3.1 With dummy fuses in place and carrying rated current c
14、ontinuously, the temperature on a materialor component or electrical insulation shall not exceed the values in Table 8.4A.Exception: If the fuse and fuseholder form an integral device intended to be replaced as a unit, then theactual fuse, not a dummy fuse, may be used in testing. If the actual fuse
15、 is used, the applicabletemperature limits shall be the limits specified in Table 8.4A plus 20C.8.4.3.2 Dummy fuses shall be unplated copper and shall emulate the dimensions of the intended fuse.8.4.3.3 The temperatures specified in Table 8.4A are based on an assumed ambient temperature of 25C(77F).
16、 A test may be conducted at an ambient temperature within the range of 20 - 40C (68 - 104F).8.4.3.4 During a test conducted at an ambient temperature of 25C (77F), an observed temperature shallnot exceed the required value specified in Table 8.4A.8.4.3.5 If a test is conducted at an ambient temperat
17、ure other than 25C (77F), an observed temperatureshall be corrected as described in 8.4.3.6. Neither a corrected temperature nor an observed temperatureshall exceed the required value specified in Table 8.4A.8.4.3.6 An observed temperature shall be corrected by addition if the ambient temperature is
18、 lower than25C (77F) or subtraction (if the ambient temperature is higher than 25C) of the difference between25C and the ambient temperature.8.4.3.7 If a corrected temperature exceeds the required value specified in Table 8.4A, at the request ofthe manufacturer, the test may be repeated at an ambien
19、t temperature closer to 25C (77F).JULY 30, 2010 SUBJECT 4248-18 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL8.4.4 Acceptability of test results8.4.4.1 The temperature limits shown in Table 8.4A shall not be exceeded.Table 8.4AMaximum temp
20、eratureMaterials and componentsDegreesCFA. COMPONENTS1. Any bus, strap, or fuse clip 55 1312. Pressure terminal connectors for field installed conductors. 55a131aB. ELECTRICAL INSULATION - GENERAL1. Wire insulation or insulating tubing 40b104b2. Electrical tape 60b140b3. Varnished cloth insulation 6
21、5b149b4. Fiber employed as electrical insulation 70b158b5. Sealing compound 55b131b6. Polymeric materials employed as electrical insulation or as apart the deterioration of which would result in a risk of fire,electric shock, or injury to personsRTI-20cRTI-68caApplicable to a connector for copper wi
22、re; also applicable to a connector for aluminum wire or an aluminum-bodied connector ifthe connector has a temperature rating of 90C (194F).bThis limitation for an insulated conductor or other material that has been investigated and found acceptable at a highertemperature shall be that higher temper
23、ature less 20 degrees Celsius (to represent the additional heating effect contributed bythe use of actual fuses).cc RTI is the higher of the mechanical and electrical relative thermal Indices for the polymeric material used or, for thosematerials lacking published RTI ratings, the generic thermal in
24、dex, corresponding to the material used, as published in Annex B,Reference 8.8.5 Verification of withstand rating8.5.1 Single pole fuseholders shall be tested with two single pole fuseholders mounted side by side asclose together as their configuration permits and with their major axis parallel. The fuseholders are to bewired in series with each other. Multi-pole fuseholders shall similarly be wired with each single fuseholderwired in series with its companion(s).JULY 30, 2010SUBJECT 4248-186
