1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULJune 4, 20131UL 2579OUTLINE OF INVESTIGATIONFORLOW-VOLTAGE FUSES FUSES FOR PHOTOVOLTAIC SYSTEMSISSUE NO: 9June 4, 2013Summary of TopicsThis ninth issue of the Outline of Investigation for Low-Vol
2、tage Fuses -Fuses for Photovoltaic Systems, UL 2579, includes the addition of aconstruction to allow integral wire terminations.COPYRIGHT 2013 UNDERWRITERS LABORATORIES INC.UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULJUNE 4, 2013UL 25792No
3、 Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULCONTENTSLow-Voltage Fuses Fuses for Photovoltaic Systems1 General 41.1 Scope .44 Classification .45 Characteristics 45.2 Voltage rating 45.4 Frequency .45.5 Interrupting rating
4、.56.1 Marking of fuses 57 Construction 58 Tests 58.2 Verification of temperature rise and current-carrying capacity 68.3 Verification of overload operation .68.4 Verification of operation rated voltage .68.5 Verification of peak let-through characteristics and I2t. 69.0 Service Environment Condition
5、s .79.1 Verification of freedom from unacceptable levels of thermally induced drift 79.2 Verification of functionality at temperature extremes 710.0 Current Cycling 7JUNE 4, 2013 UL 2579 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULLow-Vol
6、tage Fuses Fuses for Photovoltaic Systems1 GeneralNote: This Outline of Investigation is intended to be read together with the Standard for Low-VoltageFuses - Part 1: General Requirements, UL 248-1, hereafter referred to as UL 248-1. The numbering ofthe Clauses in this Outline of Investigation corre
7、sponds 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 Fuses for Photovoltaic Systems rated up to 1500 V dc.Fuses for Photovoltaic Systems are intended to be used for the protec
8、tion of strings or arrays ofPhotovoltaic cells and their associated wiring to provide protection against overloads or low-level shortcircuits. These types of fuses are not intended to protect downstream inverter components, such ascapacitors or the discharge of such capacitors back into the arrays o
9、r the array wiring above the fuseinterrupting rating.These fuses may also have integral wiring terminations intended for in-line connection in a photovoltaicsystem, such as connection to or between PV modules or panels.4 ClassificationFuses for Photovoltaic Systems are non-renewable, are not current
10、-limiting and have an interrupting ratingof 10ka. Time-delay ratings are optional.5 Characteristics5.2 Voltage ratingThe voltage rating may be up to 1500 V dc. Preferred ratings are 600 V, 750 V, 1000 V, 1250 V and 1500V.5.4 FrequencyNot applicableJUNE 4, 2013UL 25794UL COPYRIGHTED MATERIAL NOT AUTH
11、ORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL5.5 Interrupting rating10 ka minimum6.1 Marking of fusesIn addition to the markings required in UL 248-1, the fuse must be marked with the letters “PV” or “gPV”or the text, “Photovoltaic Fuse”.Fuses with integral wiring termina
12、tions shall also be marked in accordance with the Standard for WireConnectors, UL 486A-486B. The marking may be on the fuse, a unit container, or an information sheet.7 ConstructionIn addition to meeting the construction requirements of UL 248-1, a fuse with integral wiring terminationsshall also me
13、et the construction requirements of the Standard for Wire Connectors, UL 486A-486B.8 Tests8.1 A fuse with integral wiring terminations shall additionally be investigated to the mechanical sequencerequirements of the Standard for Wire Connectors, UL 486A-486B.For fuses with integral wiring terminatio
14、ns, all test samples shall be wired based on the instructions of themanufacturer.Table 1Number of Fuses to be testedTest Test Temperature50 C Ambient Total iftime delayTotal if nottime delay8.2 Verification of temperature rise and In3338.3 Verification of overload operationa) tmax(1.35 In)3b) tmax(2
15、.0 In)22c) tmin(2.0 In)118.4 Verification of operation at rated voltagea) 2.0 In111b) 10ka 1 1 19.1 Verification of freedom from unacceptable levels ofthermally induced driftVerification of temperature rise and In333Verification of overload operationa) tmax(1.35 In)3b) tmax(2.0 Inc) tmin(2.0 InVerif
16、ication of operation at rated voltagea) 2.0 In333b) 10ka 3 3 39.2 Verification of functionality at temperature extremesVerification of In111Verification of overload operationJUNE 4, 2013 UL 2579 5Table 1 Continued on Next PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBU
17、TION WITHOUT PERMISSION FROM ULTable 1 ContinuedTest Test Temperature50 C Ambient Total iftime delayTotal if nottime delaya) tmax(1.35 In)11110.0 Current cycling 18 18 18Total Samples 2 47 49 458.2 Verification of temperature rise and current-carrying capacity1.0 In Temperature rise and current carr
18、ying capacity.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 rated voltageFor DC UL 248-1, Table 6Test 1 10kA, except the time constant shall be 1ms or lessTest 5c2In,
19、 except the time constant shall be 1ms or less8.5 Verification of peak let-through characteristics and I2t.Not applicableJUNE 4, 2013UL 25796UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL9.0 Service Environment Conditions9.1 Verification of
20、freedom from unacceptable levels of thermally induced drift9.1.1 Fifteen samples of each device (18 samples for time-delay fuses) are each to be subjected totemperature cycling consisting of 50 cycles of heating and cooling; each cycle consisting of 15 minutes at-40 C followed by 15 minutes at 90 C
21、(any convenient ramp rate). At the conclusion of the 50 cycles,the samples shall be returned to room temperature (23 3) for a minimum of 3 hours.9.1.2 At the conclusion of the temperature cycling, three samples are each to be subjected to the testsdescribed in 8 of this document.Exception: The verif
22、ication of temperature rise is not required to be repeated but the verification ofcurrent carrying capacity (In) is.9.2 Verification of functionality at temperature extremes9.2.1 Two samples of each device are each to be conditioned at 50 C. While being maintained at thattemperature, one fuse is to
23、be subjected to the verification of 1.0 Inand the other to the Verification ofOverload at 1.35 In(see Table 1).10.0 Current Cycling10.1 Measure and record the resistance of the eighteen fuses to be used in tests in this Section.10.2 Nine samples of each device are each to be subjected to temperature
24、 cycling consisting of 50 cyclesof heating and cooling; each cycle consisting of 15 minutes at -40C followed by 15 minutes at 90C (anyconvenient ramp rate). At the conclusion of the 50 cycles, the samples shall be returned to roomtemperature (233) for a minimum of 3 hours.10.3 At the conclusion of t
25、he temperature cycling, the nine samples are each to be subjected to thecurrent cycling described in 10.5.10.4 Nine samples of each device are each to be conditioned in a humidity chamber at 25 C 90-100%relative humidity for a minimum of 5 days. Within one hour of removal from the humidity chamber,
26、the ninesamples are each to be subjected to the current cycling described in 10.5.10.5 Each of the nine samples is to undergo 3000 repetitions of current cycling where one cycle isrepresented below:Exception: The number of samples, rated 100 amperes or more, to be subjected to current cycling is tob
27、e reduced from 18 to 6 with three samples being subjected to temperature cycling as described in 10.2and three samples to be subjected to humidity conditioning as described in 10.4, before, in each case,being subjected to current cycling.This is generated text for figtxt.JUNE 4, 2013 UL 2579 7UL COP
28、YRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL10.6 Each group of samples shall be returned to room temperature and again measured. Samples wherethe resistance measured differs by more than 10% from the initial resistance measurement taken in 10.1are considered failures and are unacceptable. Additionally, none of the samples shall exhibit cracking orcrazing of the fuse body.JUNE 4, 2013UL 25798
