1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULJuly 23, 20101SUBJECT 248-18OUTLINE OF INVESTIGATIONFORLOW VOLTAGE FUSES CLASS CD FUSESIssue Number: 4July 23, 2010Summary of TopicsThis fourth issue of SU 248-18 is being issued with no substant
2、ivechanges. The First through Third issues of the Outline for Low VoltageFuses - Class CD Fuses were numbered SU 2126.COPYRIGHT 2010 UNDERWRITERS LABORATORIES INC.UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULJULY 23, 2010SUBJECT 248-182No T
3、ext on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULCONTENTS1 General 41.1 Scope .44 Classification .45 Characteristics 45.2 Voltage rating 45.3 Current rating 45.5 Interrupting rating .45.6 Peak let-through current and clearing I2
4、t characteristics .57 Construction 57.1 Dimensions 58 Tests 78.2 Verification of temperature rise and current-carrying capacity 78.3 Verification of overload operation .78.4 Verification of operation at rated voltage .78.5 Verification of peak let-through current and clearing I2t characteristics 8JU
5、LY 23, 2010 SUBJECT 248-18 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULLow-Voltage Fuses Class CD Fuses1 GeneralNote: This Outline of Investigation is intended to be read together with UL 248-1, the Standard forLow-Voltage Fuses Part 1: G
6、eneral Requirements, hereafter referred to as UL 248-1. The numbering ofthe Clauses in this Outline of Investigation corresponds to like numbered Clauses in UL 248-1. Therequirements of UL 248-1 apply unless modified by this Outline of Investigation.1.1 ScopeThis Outline of Investigation applies to
7、Class CD fuses rated 31 60 A and 600 V ac. DC ratings areoptional.4 ClassificationClass CD Fuses are non-renewable and current-limiting with an interrupting rating of 200,000 A.Time-delay ratings are optional.5 Characteristics5.2 Voltage ratingFor AC, the rating shall be 600 V ac.The DC voltage rati
8、ng may be different from the AC rating.5.3 Current rating3160A.5.5 Interrupting ratingFor AC 200,000 AFor DC, the preferred ratings are 10,000, 20,000, 50,000, 100,000, 150,000, or 200,000 A.JULY 23, 2010SUBJECT 248-184UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WI
9、THOUT PERMISSION FROM UL5.6 Peak let-through current and clearing I2t characteristicsMaximum values of peak let-through current and clearing I2t are given in Table A.Table A Maximum peak let-through current and clearing I2t for Class CD fusesCurrent ratingIn,ABetween threshold and 50 kA At 100 kA At
10、 200 kAPeak let-throughcurrent, AI2t, ampere-squaredsecondsPeak let-throughcurrent, AI2t, ampere-squaredsecondsPeak let-throughcurrent, AI2t, ampere-squaredseconds31 60 8,000 30,000 10,000 30,000 16,000 30,0007 Construction7.1 DimensionsFuse dimensions are shown in Figure A.This is generated text fo
11、r figtxt.JULY 23, 2010 SUBJECT 248-18 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULFigure A Dimensions of Class CD fuses in mm (in)Current ratingIn,AOverall length Ferrule length FerrulediameterRejectionlengthRejectiondiameterRejectionferr
12、ule lengthABCKMB147.74 10.64a17.91 2.44b,c21.59b13.21a31 60 (1.880) (0.419) (0.705) (0.096) (0.850) (0.520)aTolerances: 0.26 mm (0.010 in)bTolerances: 0.52 mm (0.020 in)cThe fuse shall be constructed so that it will not conduct current when installed in a 30A Class J fuseholder.JULY 23, 2010SUBJECT
13、248-186UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL8 Tests8.2 Verification of temperature rise and current-carrying capacity1.0 In Temperature rise1.1 In Current-carrying capacity, Inf8.2.3.1 Fuses rated 60 A or lessIn addition to the requ
14、irements in UL 248-1: At the conclusion of the temperature rise test, the test currentshall be increased without interruption to 1.1 Infor a period of not less than 15 min. Temperature is notto be monitored during this time.8.2.4 Acceptability of test resultsThe maximum temperature rise shall not ex
15、ceed the following:Body 95C;Contacts 55C;8.3 Verification of overload operationUL 248-1, Table 4Test 1 1.35 InTest 3 2.0 InTest 4 2.0 Infor time-delay fuses only (can be combined with Test 3)8.4 Verification of operation at rated voltageFor AC UL 248-1, Table 5Test 1 200 kATest 2 Maximum energyTest
16、3 Threshold ratio. The maximum threshold ratio shall be 30.Test 4a 100 kATest 4b 50 kATest 5b2InPeak let-through current and clearing I2t recorded during tests 1, 4a, and 4b.For DC (optional) UL 248-1, Table 6Test 1 Interrupting ratingJULY 23, 2010 SUBJECT 248-18 7UL COPYRIGHTED MATERIAL NOT AUTHORI
17、ZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULTest 2 Maximum energyTest 5a9Infor time-delay fuses onlyTest 5c2In8.5 Verification of peak let-through current and clearing I2t characteristics8.5.3 Acceptability of test resultsIn addition to the requirements in UL 248-1: Peak let-through current and clearing I2t values recorded shallnot exceed the limits specified in Table A.JULY 23, 2010SUBJECT 248-188
