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HIGH VOLTAGE DIN DISTRIBUTION FUSES
General Guide to the Selection of Fuses.
For use in the Primary Circuit of Three-Phase Transformers
Transformer
3ph kVA Fuse Reference and Rating in Amps
Fuse kV 3.6kV 7.2kV 12kV 17.5kV 24kV
System kV 2.4kV 4.16kV 6.9kV 10kV 12.47kV 13.2kV 13.8kV 15.5kV 20kV 25kV
25 ADLSJ 16 SDLSJ 10 SDLSJ 6.3 SDLSJ 6.3 SDMSJ 6.3 SDMSJ 6.3 SDMSJ 6.3 SDMSJ 6.3 SDMSJ 6.3 SDMSJ 6.3
30 ADLSJ 16 SDLSJ 10 SDLSJ 6.3 SDLSJ 6.3 SDMSJ 6.3 SDMSJ 6.3 SDMSJ 6.3 SDMSJ 6.3 SDMSJ 6.3 SDMSJ 6.3
40 ADLSJ 20 SDLSJ 16 SDLSJ 10 SDLSJ 6.3 SDMSJ 6.3 SDMSJ 6.3 SDMSJ 6.3 SDMSJ 6.3 SDMSJ 6.3 SDMSJ 6.3
45 ADLSJ 20 SDLSJ 16 SDLSJ 10 SDLSJ 6.3 SDMSJ 6.3 SDMSJ 6.3 SDMSJ 6.3 SDMSJ 6.3 SDMSJ 6.3 SDMSJ 6.3
63 ADLSJ 31.5 SDLSJ 20 SDLSJ 16 SDLSJ 10 SDMSJ 10 SDMSJ 10 SDMSJ 6.3 SDMSJ 6.3 SDMSJ 6.3 SDMSJ 6.3
75 ADLSJ 40 SDLSJ 25 SDLSJ 16 SDLSJ 10 SDMSJ 10 SDMSJ 10 SDMSJ 10 SDMSJ 10 SDMSJ 6.3 SDMSJ 6.3
100 ADLSJ 40 SDLSJ 25 SDLSJ 20 SDLSJ 10 SDMSJ 10 SDMSJ 10 SDMSJ 10 SDMSJ 10 SDMSJ 10 SDMSJ 6.3
112 ADLSJ 40 SDLSJ 31.5 SDLSJ 20 SDLSJ 16 SDMSJ 10 SDMSJ 10 SDMSJ 10 SDMSJ 10 SDMSJ 10 SDMSJ 6.3
125 WDLSJ 50 SDLSJ 31.5 SDLSJ 25 SDLSJ 16 SDMSJ 10 SDMSJ 10 SDMSJ 10 SDMSJ 10 SDMSJ 10 SDMSJ 10
150 WDLSJ 50 SDLSJ 40 SDLSJ 25 SDLSJ 16 SDMSJ 16 SDMSJ 16 SDMSJ 16 SDMSJ 10 SDMSJ 10 SDMSJ 10
200 WDLSJ 63 SDLSJ 50 SDLSJ 31.5 SDLSJ 20 SDMSJ 16 SDMSJ 16 SDMSJ 16 SDMSJ 16 SDMSJ 10 SDMSJ 10
225 WDLSJ 80 SDLSJ 50 SDLSJ 40 SDLSJ 20 SDMSJ 16 SDMSJ 16 SDMSJ 16 SDMSJ 16 SDMSJ 10 SDMSJ 10
300 WDLSJ 100 SDLSJ 63 SDLSJ 40 SDLSJ 25 SDMSJ 20 SDMSJ 20 SDMSJ 20 SDMSJ 20 SDMSJ 16 SDMSJ 10
400 WDLSJ 125 SDLSJ 80 SDLSJ 50 SDLSJ 31.5 SDMSJ 31.5 SDMSJ 25 SDMSJ 25 SDMSJ 20 SDMSJ 20 SDMSJ 20
450 WFLSJ 160 SFLSJ 80 SDLSJ 63 SDLSJ 40 SDMSJ 31.5 SDMSJ 31.5 SDMSJ 31.5 SDMSJ 25 SDMSJ 20 SDMSJ 20
500 WFLSJ 160 SFLSJ 100 SDLSJ 63 SDLSJ 40 SDMSJ 31.5 SDMSJ 31.5 SDMSJ 31.5 SDMSJ 31.5 SDMSJ 25 SDMSJ 20
600 WFLSJ 200 SFLSJ 125 SFLSJ 80 SFLSJ 50 SDMSJ 40 SDMSJ 40 SDMSJ 40 SDMSJ 31.5 SDMSJ 25 SDMSJ 20
750 WKLSJ 250 SFLSJ 160 SFLSJ 80 SFLSJ 63 SFMSJ 50SDMSJ 50 SDMSJ 40 SDMSJ 40 SDMSJ 31.5 SDMSJ 25
1000 WKLSJ 315 WKMSJ 200 SFLSJ 125 SFLSJ 80 SFMSJ 63SFMSJ 63 SFMSJ 63 SFMSJ 50 SFMSJ 40 SDMSJ 31.5
1250 WKLSJ 400 WKMSJ 250 SFLSJ 160 SFLSJ 100 SFMSJ 80SFMSJ 80 SFMSJ 80 SFMSJ 63 SFMSJ 50 SFMSJ 40
1500 – WKMSJ 315 SFLSJ 160 SKLSJ 125 SFMSJ 100* SFMSJ 100* SFMSJ 80 SFMSJ 80 SFMSJ 63 SFMSJ 50
2000 – – WKMSJ 250 – SKMSJ 125* SKMSJ 125* SKMSJ 125* SFMSJ 100* SFMSJ 71 –
2500 – – WKMSJ 315 – – – – SKMSJ 125* – –
*Fuse rated 15.5kV max.
Selection of these fuses has been based on a compromise between the following:
1.The fuse should withstand transformer magnetizing inrush currents, taken as 12 times full load current for 0.1 seconds.
2.The fuse should discriminate with the highest rating of the secondary fuse likely to be used.
3.The fuse should operate reasonably quickly in the event of a transformer inter-turn fault or a fault in the secondary terminal zone of the transformer.
NOTES:
A.In general, the recommendations apply equally to the use of fuse in open air or in an encapsulated enclosure, since “1” and “2” above dictate the use of a fuse cur-
rent rating sufficiently above the transformer current rating to nullify any adverse thermal affect of encapsulation. However, if the transformer is subjected to long
time overcurrents, a higher rate of fuse may be required.
B. The above recommendations are not generally applicable to transformers feeding motor circuits with starting currents in excess of the rated current of the fuse. In
this event, please consult your local Edison office.
C. Recommendations for other voltages are available on request.
D. While the above recommendations give a good general guide, recommendations for specific cases will be sent on receipt of full details of the application.
