High Speed Fuses High Speed Fuses Section Contents Page General Applications .122-123 North American fuses & accessories .124-141 DFJ - High speed Class J fuse 125 Square Body fuses & accessories 142-213 BS 88 fuses & accessories 214-222 Ferrule fuses & accessories 223-243 Scan this tag to get the latest product information for High Speed Fuses. 121 TMHigh Speed Fuses General Applications X Rated Voltage Power Factor The AC voltage rating of Bussmann fuses is given in volts For other power factor 1.0 rms. Fuses tested to IEC are tested at 5% above their rated values, the total clearing voltage. British Style BS 88 fuses are tested at 10% above integral can be its rated voltage. UL recognition tests are performed at the calculated as a multiple 0.9 rated voltage. of the clearing integrals, the correction factor K Rated Current and the correction factor Rated current is given in amps rms. Bussmann fuses can X. 0.8 continuously carry the rated current. Melting Characteristic 0.7 4 Arc Voltage The melting 10 0.1 0.2 0.3 0.4 0.5 6 COS w characteristic 4 This curve gives the 2 1.4 shows the virtual 3 peak arc voltage, U , 10 U 1.2 L L melting time in 6 which may appear 3 4 10 seconds as a 2 9 across the fuse during its function of the 2 10 8 operation as a function 6 prospective current 7 4 of the applied working in amps rms. The 2 6 1 10 voltage, E , (rms) at a fuses are specially g 5 6 4 constructed for power 2 4 short-circuit factor of 15%. 0 10 Eg protection against 6 3 4 Power Losses 200 300 400 500 600 660 high level fault 2 1 currents. Loading 10 Watts loss at rated 1.0 6 Kp and operation of 4 0.8 current is given in the 2 the fuse in the non- 0.6 electrical characteristics. 2 10 continuous/dashed 0.5 6 The curve allows the 4 section of the melt 0.4 2 calculation of the power curve must be 3 0.3 10 losses at load currents 6 avoided. The curve 4 lower than the rated 0.2 can also be read 2 4 current. The correction as the real melting 10 1 2 3 10 242 68 10 242 68 10 Prospective Current In Amperes RMS time as a function factor, K , is given as a p I b 0.1 of the RMS value function of the RMS load 30 40 50 60 70 80 90 100% of the pre-arc current. current, I , in % of the b rated current. 1.5 Clearing Integrals K 2 Cut-Off Current The total clearing I t at 1.0 rated voltage and at A fuse operation relating to short-circuits only. When a fuse power factor of 15% are operates in its current-limiting range, it will clear a short- given in the electrical 5 10 0.5 characteristics. For 0.4 other voltages, the 2 0.3 clearing I t is found by 4 10 multiplying by correction 0.2 factor, K, given as a E g 3 A 10 function of applied B 100 200 300 400 500 600 660 working voltage, E , g 2 2 10 (rms). 2 3 4 5 6 10 10 10 10 10 Prospective Current in Amps RMS 1 circuit in less than 2 cycle. Also, it will limit the instantaneous peak let-through current to a value substantially less than For product data sheets, visit www.cooperbussmann.com/DatasheetsEle 122 Virtual Pre-Arcing Time In Seconds Peak Let-Through Current