URT
URT
Checking the time-current-curve of the rating 355A at 1020s: 560A
560 A >= 260A / 0.6 = 433A
Checking the time-current-curve of the rating 355A at 300s: 650A
650A >= 340A / 0.6 = 567A
Based on the above calculation, a fuse rating of 355A will carry the load represented in the diagram continuously. As a next step, one should observe the of the semiconductor and compare them with the fuse integral. In this case it may be necessary to reduce the fuse rated current. Extraordinary Overloads An impulse load on the D.C. side of a converter causes a current through the fuse link as shown in the load diagram. A load-break-switch interrupts such a load in a period of <200ms. One should determine whether the fuse link can carry the current for the duration of the overload without interruption.
I 1 max = 2000A
t 1 = 14ms
( I 1 RMS about 1300 A ) I 2 RMS = 900A SQB Fuse Link Size 1 Rated current 355A Cf3 = 0.8
t 2 = 200ms
Review of the load first wave and the load-RMS value, and comparison with the time-current-curve(TCC) of the rating of 355A: I TCC >= I n / Cf3
Checking the time-current-curve of the rating 355A at 14ms: 1900A
1900A >= 1300A / 0.8 = 1625 A
Checking the time-current-curve of the rating 355A at 200ms: 1600A
1600A >= 900A / 0.8 = 1125 A Based on the above calculation, a fuse rating of 355 A will carry the load according to the diagram continuously.
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