Low Voltage Fuses BLC, CR and CS types Super Rapid Fuses BLC, CR and CS types Super Rapid Fuses 150–1500 Volts AC 10–4700 Amps � Description The FUJI BLC, CR and CS types are extremely reliable fuses which have been specially developed to provide protection for silicon diodes and thyristors and are suitable for inverters using semiconductors or transformers- SD-36 SM-388 SI-431 SI-429 rectifiers. FUJI Super Rapid Fuses are BLC CR2L CS5F CS10F 2 designed with a very small total I t value which gives them a high speed semiconductors short or circuits fail the • High interrupting capacity of 200kA interrupting action in the face of sound elements will be quickly isolated at 1000V AC abnormal currents. from the fault circuits. • The CS type is provided with a blown In addition the arc voltage generated at fuse indicator. An alarm contact the time of interruption has a low value � Features block (1NO or 1NC) can also be so that faults will not influence related 2 • The total clearing I t is small and the attached. electric machinery and equipment. semiconductor circuit is completely These fuses can carry out the protected. � UL recognized: CR2L/UL,CR2LS/UL, protection of many types of circuits • Since the peak arc voltage at the CR6L/UL rating from the semiconductor time of interruption is low damage to (File No. E92312) overcurrents to destructive short- other equipment does not occur. CSA certificated: CR2LS/UL circuiting faults-i.e. when the (File No. LO4000-4090) TÜV: CR2LS/UL (10-100A), CR2L/UL (150-350A) (Rep. No. E9450643E02) CR6L/UL (50-300A) (Rep. No. E9560543E02) � Specifications Rated Rated Peak Max. Watt Fuse-link Rated Rated Peak Max. Watt Fuse-link 2 2 current voltage arc interrupting I t loss current voltage arc interrupting I t loss 2 2 voltage (Amp ×sec.) voltage (Amp ×sec.) 3 3 × 10 Type × 10 Type (A) (V) (W) (A) (V) (W) 12 550V 1550 0.09 5.1 BLC012-1 10 250V Max. 0.04 1.2 CR2LS-10 20 AC 1550 0.27 8.5 BLC020-1 20 AC 500 0.17 3.0 CR2LS-20 30 0.35 4.0 CR2LS-30 23 1550 0.39 10 BLC023-1 45 1380 1.8 19 BLC045-1 50 0.85 6.0 CR2LS-50 75 2.3 9.0 CR2LS-75 75 1250 5 32 BLC075-1 08 90 1250 11.5 38 BLC090-1 100 4.0 12.0 CR2LS-100 120 1200 33 51 BLC120-1 20 600V Max. 0.14 4.0 CR6L-20 140 1200 100 59 BLC140-1 30 AC 1200 0.35 7.0 CR6L-30 30 250V Max. 0.35 4.0 CR2L-30 50 1.8 9.0 CR6L-50 75 3.0 12.5 CR6L-75 50 AC 500 0.85 6.0 CR2L-50 75 2.3 9.0 CR2L-75 100 7.0 15 CR6L-100 100 4.0 12.0 CR2L-100 125 6.5 14.0 CR2L-125 150 18 22.0 CR6L-150 140 7.0 16.0 CR2L-140 200 30 34.0 CR6L-200 150 9.5 18.0 CR2L-150 250 70 37.0 CR6L-250 300 95 40.0 CR6L-300 175 13 21.0 CR2L-175 350 150 45.0 CR6L-350 200 17 23.0 CR2L-200 400 200 55 CR6L-400 225 22 26.0 CR2L-225 500 390 60 CR6L-500 260 27 30.0 CR2L-260 600 700 70 CR6L-600 300 38 35.0 CR2L-300 325 49 37.0 CR2L-325 Interrupting capacity 350 60 37.0 CR2L-350 CR2LS . 100kA at 250V AC CR6L .... 100kA at 600V AC 400 103 39.0 CR2L-400 450 140 46.0 CR2L-450 500 160 48.0 CR2L-500 550 200 51.0 CR2L-550 600 215 56.0 CR2L-600 Interrupting capacity BLC ...... 100kA at 550V AC CR2L .... 100kA at 250V AC Fuji Electric FA components & Systems Co., Ltd./D & C Catalog Information subject to change without notice http://store.iiic.cc/ 08/35 Low Voltage Fuses BLC, CR and CS types Super Rapid Fuses � Specifications � Specifications (UL-recognized, CSA certified, TÜV) Rated Inter- Max. Watt Fuse-link Rated Rated Inter- Max. Watt Fuse-link 2 2 current rupting interrupting I t loss current voltage rupting interrupting I t loss 2 2 capacity (Amp ×sec.) capacity (Amp ×sec.) 3 3 × 10 Type × 10 Type (A) (kA) (W) (A) (kA) (W) 4700 150 at 14000 310 CS1F-4700 10 250V AC 10 at AC 0.04 1.2 CR2LS-10/UL 125V AC 20 400V DC (pf: 0.8) 0.17 3.0 CR2LS-20/UL 30 10 at DC 0.35 4.0 CR2LS-30/UL 2000 150 at 1950 124 CS2F-2000 50 (L/R: 2ms) 0.85 6.0 CR2LS-50/UL 3000 250V AC 5500 216 CS2F-3000 75 2.3 9.0 CR2LS-75/UL 40 200 at 1 6.4 CS5F-40 100 4.0 12.0 CR2LS-100/UL 75 500V AC 3.5 12 CS5F-75 100 5 17 CS5F-100 150 10 25 CS5F-150 150 9.5 18.0 CR2L-150/UL 200 18.5 34 CS5F-200 200 17 23.0 CR2L-200/UL 250 33 42 CS5F-250 260 27 30.0 CR2L-260/UL 350 60 37.0 CR2L-350/UL 300 64 45 CS5F-300 400 103 39.0 CR2L-400/UL 350 85 56 CS5F-350 450 140 46.0 CR2L-450/UL 400 122 57 CS5F-400 500 160 48.0 CR2L-500/UL 450 131 62 CS5F-450 550 200 51.0 CR2L-550/UL 500 159 73 CS5F-500 600 215 56.0 CR2L-600/UL 600 257 80 CS5F-600 20 600V AC 100 at AC 0.14 4.0 CR6L-20/UL 800 600 114 CS5F-800 680V DC (pf: 0.8) 1000 1200 110 CS5F-1000 30 10 at DC 0.35 7.0 CR6L-30/UL 1000 843 167 CS5F-1000-P (L/R: 2ms) 1200 1800 114 CS5F-1200 50 1.8 9.0 CR6L-50/UL 1200 1311 200 CS5F-1200-P 75 3.0 12.5 CR6L-75/UL 1500 3600 209 CS5F-1500 100 7.0 15.0 CR6L-100/UL 1000 200 at 1800 125 CS8F-1000 1200 800V AC 2500 176 CS8F-1200 150 100 at AC 18 22.0 CR6L-150/UL 1500 4400 220 CS8F-1500 (pf: 0.8) 200 50 at DC 30 34.0 CR6L-200/UL 80 200 at 10 17 CS10F-80 (L/R: 2ms) 100 1000V AC 16 21 CS10F-100 300 95 40.0 CR6L-300/UL 150 37 27 CS10F-150 200 63 37 CS10F-200 Note: • Peak arc voltage 250 110 44 CS10F-250 CR2LS, CR2L .... Max. 500V CR6L .................. Max. 1200V 300 148 53 CS10F-300 • The peak arc voltage is obtained by interruption caused by the listed 350 211 70 CS10F-350 interrupting current at rated voltage. 400 307 74 CS10F-400 • This indcates the values when the conductors specified in UL 500 420 90 CS10F-500 Standards are connected and rated current apply. 560 410 102 CS10F-560 • TÜV: CR2LS, 2L: Up to 350A 630 450 135 CS10F-630 CR6L: 50 to 300A 750 640 156 CS10F-750 800 1259 211 CS10F-800-P � CR type fuse with optional accessory 1000 1722 245 CS10F-1000-P 1250 2250 330 CS10F-1250-P Fuse with blown indication fuse 1500 3200 334 CS10F-1500-C CR2L (S)- G 450 100 at 350 134 CS15F-450 630 1500V AC 760 170 CS15F-630 900 1400 280 CS15F-900-P 1250 3050 350 CS15F-1250-P Note: • Peak arc voltage CS1F ..... Max. 450V CS2F ..... Max. 750V CS5F ..... Max. 1000V AF88-446 CS8F ..... Max. 2000V CS10F ... Max. 2000V CS15F ... Less than 3000V • An alarm contact block AHX2905 (1NO) or AHX2915 (1NC) can be Fuse with blown indication fuse and precision switch attached to CS type. (Sold separately) See page 08/44. CR2L (S)- S Precision switch (SPDT) CRX-1 Note: UL recognized fuse In the UL recognized fuses, a fuse with a blown inidcation fuse, or a fuse both with a blown indication fuse and a precision switch is also UL recognized. Examples: CR2L-200G/UL CR2LS-30S/UL precision switch CR6L-100G/UL AF88-445 AF88-442 Fuji Electric FA components & Systems Co., Ltd./D & C Catalog Information subject to change without notice http://store.iiic.cc/ 08/36 Low Voltage Fuses BLC, CR and CS types Super Rapid Fuses � Dimensions, mm � CR2L-450 or smaller, CR2LS D B � BLC BLC012, 020, 023 BLC045 BLC075 to 140 şD şD şD Mounting hole a × b şd şd şd H F Type Rated A B şD şd Color of Mass Blown indicatin current indicator (g) fuae (G type) (A) BLC012-1 12 50 10 13 10 Grey 12 BLC020-1 20 50 10 13 14 Yellow 12 BLC023-1 23 50 10 13 14 Violet 12 BLC045-1 45 50 10 27 20 White 62 A BLC075-1 75 63 6 34 5 Silver 120 BLC090-1 90 63 6 34 8 Red 120 Type A B C D E a×b F G H Mass BLC120-1 120 63 6 47 8 Yellow 120 CR2L-30 80 58 18 21.5 37 9×11 90 1.5 26.5 42g BLC140-1 140 63 6 47 8 Light red 215 CR2L-50 Note: The BLC type fuse link requires a holder in use. The size of the CR2L-75 80 58 20 30.5 44 9×11 90 3 32.5 100g holder differs according to the fuse ratings. Select the most suitable CR2L-100 one after referring to the Table on page 08/44. CR2L-125 For drawings see page 08/32. CR2L-140 CR2L-150 CR2L-175 CR2L-200 85 60 25 33.5 47 11×13 93 3.2 33.5 130g CR2L-225 CR2L-260 � Ordering information CR2L-300 Specify the following: CR2L-325 1. Type number CR2L-350 95 70 30 42 54 11×13 98 4 39 220g CR2L-400 � Type number nomenclature CR2L-450 BLC 012-1 CR2LS-10 56 42 12 18.5 34.5 6.5×8.5 78 2 25 28g Rated current: 12 to 140A CR2LS-20 Plug-in type super rapid fuse CR2LS-30 CR2LS-50 CS 10F-1000 -P/ UL CR2LS-75 UL recognized (CR2L, CR2LS, CR6L) CR2LS-100 CSA certificated (CR2LS) 08 TÜV (CR2LS, CR2L, CR6L) � CR2L-500 to -600 84 70 2-fuse connected parallel 31 Optional accessory (See page 08/44) G: With blown indication fuse S: With blown indication fuse and precision switch Mounting hole 11×13 Rated current 41.5 98 10 to 4700A 43 84 46 Blown indication Rated voltage fuse (G type) 2L, 2LS: 250V AC, 6L: 600V AC 1F: 150V AC, 2F: 250V AC 5F: 500V AC, 8F: 800V AC 10F: 1000V AC, 15F: 1500V AC CR: Barrel-shaped super rapid fuse CS: Cubic-shaped super rapid fuse Mass: 450g 95 Dimensions for reference only. Confirm before construction begins. Note: The dimensions of the fuses with suffix. UL are the same as those of the standard ones. Fuji Electric FA components & Systems Co., Ltd./D & C Catalog Information subject to change without notice http://store.iiic.cc/ 08/37 B A B A B A 54 E G 28 C 46.5 8 30 ş37 Low Voltage Fuses BLC, CR and CS types Super Rapid Fuses � Dimensions, mm � CR6L-20, CR6L-30, CR6L-50 � CR6L-75 to 300 � CR6L-350 to 600 B 84 B 62 D 18.5 47 Mountng hole 11×13 41.5 Blown indication 43 Mountng hole a × b D fuse (G type) 46 Mountng hole 6.5×8.5 H 23.5 25 F 88 Blown indication 74 fuse (G type) Blown indication fuse (G type) C 76 A Mass: 42g A Type A B C D E F G H a×b Mass (g) Type A B C D Mass (g) CR6L-75 95 70 25 34 47 102 3.2 33.5 11×13 150 CR6L-350 107 82 43 107 493 CR6L-100 CR6L-400 121 96 43 114 522 CR6L-150 CR6L-500 CR6L-200 107 82 30 42 54 107 4 39 11×13 246 CR6L-600 121 96 47.4 114 545 CR6L-250 CR6L-300 � CS1F-4700 � CS5F-40 to 1500 � CS8F-1000, 1200, 1500 CS2F-2000, 3000 CS10F-80 to 750 CS15F-450, 630 Alarm contact block Alarm contat block AHX2905(NO) Alarm contact block Blown fuse indicator AHX2915(NC) Blown fuse indicator Blown fuse indicator N.P. M A B A B 51 72 2-MIO M Mass: 800g Voltage Type A B C D M Mass Voltage Type A B C D M Mass (Max.) (g) (Max.) (g) 500V CS5F-40 47 47 42.5 65.5 M8 320 800V CS8F-1000 72 74 54.5 84 M12 1060 CS5F-75 CS8F-1200 CS5F-100 CS8F-1500 72 82 54.5 84 M8 1150 CS5F-150 1000V CS10F-80 47 71 42.5 65.5 M8 420 CS5F-200 CS10F-100 CS5F-250 57 51 47 70 M8 510 CS10F-150 57 74 47 70 M8 690 CS5F-300 CS10F-200 CS5F-350 CS10F-250 CS5F-400 72 51 54.5 77 M10 800 CS10F-300 72 74 54.5 77 M10 1060 CS5F-450 CS10F-350 CS5F-500 CS10F-400 CS5F-600 CS10F-500 CS5F-800 CS10F-630 CS5F-1000 72 51 54.5 77 M12 830 CS10F-750 CS5F-1200 1500V CS15F-450 72 105 54.7 77 M10 1400 CS5F-1500 CS15F-630 Fuji Electric FA components & Systems Co., Ltd./D & C Catalog Information subject to change without notice http://store.iiic.cc/ 08/38 72 34.5 18 30 27 2 12 54.5 7 84 max. ş17.5 A E G C 7 C 7 D A 30 28 46.5 C 7 30 ş37 8 54 D Low Voltage Fuses BLC, CR and CS types Super Rapid Fuses � Dimensions, mm � Characteristic curves BLC � CS5F-P CS10F-P, CS15F-P Melting time-current characteristic Alarm contat block M10 N.P. 72 ş15 86 158 Voltage Type H L Mass (g) 500V CS5F-1000-P 51 69 1900 CS5F-1200-P 1000V CS10F-800-P 74 92 2420 CS10F-1000-P CS10F-1250-P Current (A) 1500V CS15F-900-P 105 123 3100 CS15F-1250-P Operating time-current characteristic � CS10F-1500-C 7 max.77 M10 M10 7 Alarm contat block 107 M10 108 89.5 08 ş15 72 Mass: 2500g Current (A) Current-limiting characteristic Available current (Sym, rms) I eff. (kA) Fuji Electric FA components & Systems Co., Ltd./D & C Catalog Information subject to change without notice http://store.iiic.cc/ 08/39 5 H L 72 40 74 40 5 72 99 54.5 7 max.77 7 Max. Let-through current (Peak value) kA Time Time Second Minute Second Minute Low Voltage Fuses BLC, CR and CS types Super Rapid Fuses � Characteristic curves CR6L CR2L, CR2LS Melting time-current characteristic Melting time-current characteristic Current (A) Current (A) Operating time-current characteristic Operating time-current characteristic Current (A) Current (A) Current-limiting characteristic Current-limiting characteristic Available current (Sym, rms) I eff. (kA) Available current (Sym, rms) I eff. (kA) Fuji Electric FA components & Systems Co., Ltd./D & C Catalog Information subject to change without notice http://store.iiic.cc/ 08/40 Time Time Second Minute Second Minute Max. Let-through current (Peak value) kA Time Time Max. Let-through current (Peak value) kA Second Minute Second Minute CR6L-20 CR6L-20 CR6L-30 CR6L-30 CR6L-50 CR6L-75 CR6L-50 CR6L-75 CR6L-100 CR6L-150 CR6L-100 CR6L-150 CR6L-200 CR6L-250 CR6L-20 CR6L-200 CR6L-300 CR6L-20 CR6L-250 CR6L-20 CR6L-350 CR6L-300 CR6L-400 CR6L-350 CR6L-500 CR6L-400 CR6L-600 CR6L-500 CR6L-600 Low Voltage Fuses BLC, CR and CS types Super Rapid Fuses � Characteristic curves CS1F CS2F Melting time-current characteristic Melting time-current characteristic 3 3 Current ( × 10 A) Current ( × 10 A) Operating time-current characteristic Operating time-current characteristic 08 3 3 Current ( × 10 A) Current ( × 10 A) Current-limiting characteristic Current-limiting characteristic Available current (Sym, rms) I eff. (kA) Available current (Sym, rms) I eff. (kA) Fuji Electric FA components & Systems Co., Ltd./D & C Catalog Information subject to change without notice http://store.iiic.cc/ 08/41 Time Time Max. Let-through current (Peak value) kA Second Minute Second Minute Max. Let-through current (Peak value) kA Time Time Second Minute Minute Second Low Voltage Fuses BLC, CR and CS types Super Rapid Fuses � Characteristic curves CS5F CS8F Melting time-current characteristic Melting time-current characteristic Current ( × 10A) 3 Current ( × 10 A) Operating time-current characteristic Operating time-current characteristic Current ( × 10A) 3 Current ( × 10 A) Current-limiting characteristic Current-limiting characteristic Available current (Sym, rms) I eff. (kA) Available current (Sym, rms) I eff. (kA) Fuji Electric FA components & Systems Co., Ltd./D & C Catalog Information subject to change without notice http://store.iiic.cc/ 08/42 Time Time Second Minute Second Minute Max. Let-through current (Peak value) kA Max. Let-through current (Peak value) kA Time Time Second Minute Second Minute Low Voltage Fuses BLC, CR and CS types Super Rapid Fuses � Characteristic curves CS10F CS15F Melting time-current characteristic Melting time-current characteristic Current ( × 10A) 3 Current ( × 10 A) Operating time-current characteristic Operating time-current characteristic 08 Current ( × 10A) 3 Current ( × 10 A) Current-limiting characteristic Current-limiting characteristic Available current (Sym, rms) I eff. (kA) Available current (Sym, rms) I eff. (kA) Fuji Electric FA components & Systems Co., Ltd./D & C Catalog Information subject to change without notice http://store.iiic.cc/ 08/43 Time Time Second Minute Second Minute Max. Let-through current (Peak value) kA Max. Let-through current (Peak value) kA Time Time Second Minute Minute Second Low Voltage Fuses BLC, CR and CS types Super Rapid Fuses � Operating indication Fig. 1 Fig. 3 � Blown fuse indication FUJI Super Rapid Fuses are available in BLC, CR and CS types. These types have different methods of indicating a blown fuse. � BLC type A blown fuse is indicated by the color tip on the ferrule of the fuse being Alarm contact block ejected as shown in Fig. 1. This can be AHX2905, 2915 seen through the window of the fuse SD-36 BLC type holder. � CR type CS10F SM-385 This fuse does not have a blown Fig. 2 Line Alarm indicator but if a trigger fuse is circuit connected as shown in Fig. 2 this will provide the alarm for blown fuse. Trigger � CS type F fuse This fuse is provided with a blown fuse indicator. In this case a pin in the Alarm contact pad is ejected after the fuse R SH-384 circuit has been blown. If electrical connections for lamps or alarms are CS 10F with alarm AF88-446 Load contact block required fit the contact block (1NO or CR type 1NC) to the pad as shown in Fig. 3. � Alarm contact block ratings Type Contact Rated AC DC voltage (V) Inductive cosϕ=0.3~1 Resistive load Inductive load Rated operational Rated Rated operational Rated Rated operational Rated current (A) capacity (VA) current (A) capacity (W) current (A) capacity (W) AHX2905 1NO 24 6 150 6 150 6 150 110 6 660 2.5 275 1.3 140 220 6 1320 1 220 0.45 100 AHX2915 1NC 440 2.5 1100 0.4 175 0.2 85 550 2 1100 0.3 165 0.15 85 � Fuse holder for BLC type fuse Fuse link Rated Base Screw cap Adaptor FUJI BLC fuses require special current Surface Rear ring holders. Select the most suitable one connection connection which corresponds to the rated current Type (A) Type Type Type Type of the fuse. BLC012-1 12 AFa30 Ba30 Pa30 R20 Dimensions: See page 08/32. BLC020-1 20 AFa30 Ba30 Pa30 – BLC023-1 23 AFa30 Ba30 Pa30 – BLC045-1 45 AFa60 Ba60 Pa60 – BLC075-1 75 AFa100 Ba100 Pa100 R75 BLC090-1 90 AFa100 Ba100 Pa100 – BLC120-1 120 AFa200 Ba200 Pa200 – BLC140-1 140 AFa200 Ba200 Pa200 – SD-36 AF88-439 Fuse link Fuse holder BLC Surface connection Fuji Electric FA components & Systems Co., Ltd./D & C Catalog Information subject to change without notice http://store.iiic.cc/ 08/44 Low Voltage Fuses BLC, CR and CS types Super Rapid Fuses � Application and selection guide Fig. (a) � Fuse ratings BLC, CR and CS-type – Super rapid When selecting fuses various factors fuse such as protection, coordination and When selecting fuses for load, etc. must be considered. semiconductor rectifier circuit protection However, in this catalog the main 2 t the following conditions must be matters such as voltage, current and I satisfied. only are explained. For additional details contact FUJI. Line fuse method � Rated voltage In this method the fuses are connected to � Conditions of application The rated voltage of the fuse indicates the AC line side. 1. The rated interrupting current of the the maximum operational voltage and fuse must be greater than the this also indicates the root-mean- Fig. (b) estimated short circuit current of the square value of the AC sinusoidal wave circuit. voltage. Select fuses having a rated voltage exceeding the voltage obtained Available short Rated interrupting by the formula shown in the following circuit current < current of fuse table. (Fig. 1) of rectifier circuit Do not select current-limiting fuses with 2. The let-thru current value of fuse rated voltages drastically exceeding the must be less than the allowable 1/2 rectifier circuit voltage. It is necessary cycle surge current value. to consider the arc voltage. Element fuse method Semiconductor – 1/2 Fuse let-thru In this method the fuses are connected in < cycle allowable surge current value series to the semiconductor element. = current 10ms (at 50Hz) 2 3. The total clearing I t value which the fuse requires to complete interruption 2 must be less than the allowable I t Fig. 1 Rated voltage required by fuses value of semiconductor. Wire connection Wiring diagram Rated voltage of Fuse (VFN rms) Fuse – total 2 type For line fuse For element fuse < Semiconductor – I t 2 clearing I t = 4. The rated current of the fuse must be > > Single-phase bridge E VFN a · Ea VFN a · Ea a = = greater than the average forward current of the semiconductor. Fuse – Semiconductor – > rated current average forward current E a > > 3-phase bridge VFN a · Ea VFN a · Ea = = 5. The rated current and voltage of the fuse must be greater than those of the rectifier circuit. E a 08 Fuse – rated Rectifier circuit – > > 3-phase, double star VFN a · 3 · Ea VFN a · 3 · Ea current and = = > current and voltage voltage Method of application Remarks: The 'a' is a coefficient where the regulation of the AC input voltage is taken into account. This Semiconductor rectifier equipment has is a=1.1 in case of voltage regulation ±10%. a variety of rectifier circuits. Taking the Fig. 2 Element current and line current 3-phase bridge rectifier circuit as an example – Fig. (a) and (b) as shown in Wire connection Wiring diagram Element fuse method Line fuse method the following. type Element current Ia Line current I Although the number of fuses used in I d the line fuse method (a) is half the Id __ Ia = I = d I a number used in the element fuse Single-phase bridge √ 2 I method (b), the fuses must have a = 0.707d larger current capacity. I d I Id 2 __ Ia = I= Id 3-phase bridge √ 3 3 I a = 0.577dI = 0.816dI I a I Id d __ I = Ia = I 3-phase, double star 2√ 3 = 0.289dI Fuji Electric FA components & Systems Co., Ltd./D & C Catalog Information subject to change without notice http://store.iiic.cc/ 08/45 Low Voltage Fuses BLC, CR and CS types Super Rapid Fuses 2 � Rated current The I t data for silicon diodes or Let-thru peak current (Instantaneous): The current values in fuses in the line thyristor elements are normally given in 11,600 Amps 2 S fuse system and the element fuse their respective catalogs. If the A Let-thru R.M.S. current system are different. Obtain the data is not given in their catalog obtain 11,600 ÷ 1.7 = 6,800 Amps correct current value from the table on the value in the following manner. If This example clearly shows that while page 08/48 (Fig. 2). protection is needed for a 250V, 150A a 100kA (rms, sym) current is When selecting the rated current of a (Io) diode having a maximum allowable available, the fuse limits the current let- fuse choose a fuse having an peak half sine wave current of 2700A, it thru to 6,800 Amperes (rms, sym). 2 t amperage rating greater than the is important that the fuse has a total I current which flows in the semi- value lower than that of the diode. conductor if the load is continuous and Peak let-thru current a fixed current. Calculation (Actual short-circuit current) If the current which flows in the Peak current of first half cycle 2 2 1 Peak semiconductor is greater than the rated Maximum I t diode = ( ) 0.0167 of available peak current 2 current of the fuse connect the fuses in (AC component) 2700 2 parallel. However, in this case, if the = ( ) 0.0167 Short circuit current that 2 numbers of fuses arranged in parallel would pass without current- 2 2 t value of the fuse will Sec. are 'n', then the I = 30,400A limiting fuse. 2 2 2 2 be n ·I t and n times the I t value of DC component one fuse. This should be taken into From the table (Page 08/38), the fuse 2 2 with a total I t nearest to 30,400A Sec. consideration when protective coordination is taken into account. is the 260 Ampere fuse (CR 2L-260). In the case of the circuit where the load � Interrupting current rapidly varies the fuse element will suffer from mechanical deterioration The rated interrupting current of the and be damaged by thermal stress. fuse must exceed the maximum value Time In loads of this type the deterioration (Symmetrical RMS value) of the M A characteristics of the fuse must be estimated circuit fault current. T closely considered. M:Melting time � Peak arc voltage Moreover if the fuse current – time A :Arcing time characteristics of the fuse selected is In the case of the current-limiting fuse T :Total clearing time less than the overload characteristics an arc voltage (overvoltage) is of the semiconductor element then generated at the time of interruption complete protection can be obtained. due to its fusible element construction. However, if the semiconductor element It is necessary to check that this peak Available 105,000 has a large capacity then protective arc voltage does not exceed the cooperation is very difficult to arrange. semiconductor's maximum (Non- The fuses are used to isolate the repetitive peak) reverse voltage value. shorted semiconductor element circuit from sound operating circuits. � Current limitation Let-thru 11,600 200A Select a fuse whose let-thru current 2 � Total clearing I t value does not exceed the allowable 2 The total clearing I t of fuse is a very 1/2 cycle surge current of the important factor when considering the semiconductor. The allowable surge protective coordination of the current is the peak value of the current 2 semiconductor. This total clearing I t is which in case at 50Hz is allowed to 2 the value where the arcing I t is added flow for 10ms. In the current-limiting 100,000A 2 to the melting I t. Therefore it is fuse the fault must be cleared in the Available RMS symmetrical current(Ampere) necessary to satisfy the following shortest possible time or in the first formula. 1/2 cycle. Available current is the current which Fuse – total Semiconductor < 2 2 would flow if the fuse were not current- = clearing ItI t limiting. 2 The total clearing I t of fuse depends This would cause damage to upon the operational voltage and equipment. Let-thru current is the interrupting current. actual current allowed to flow by the Therefore, for this reason if a 500 Volts current limiting action of the fuse. A fuse is used in a 300 Volts circuit the number of let-thru current graphs are 2 total clearing I t is reduced by 50–70%. given in this catalog and example is However, the reduction rate varies given in the following paragraph. The according to the type of fuse method of reading this graph is construction. This must be checked provided for your reference. and confirmed once more. How to find a let-thru current – Example Example 2 Fuse: 200 Amps 500V I t 2 2 Available R.M.S symmetrical current: All I t values are ampere seconds. 100,000 Amps Fuji Electric FA components & Systems Co., Ltd./D & C Catalog Information subject to change without notice http://store.iiic.cc/ 08/46 Available instantaneous peak current Pf=1 Let-thru peak current(Amperes)-Peak Current