| BACK-UP PROTECTION BY H.R.C. FUSES
For applications in which fault currents
larger than the contactor's breaking capacity, or with peak values higher than
those which cause the repulsion of the contacts are experienced, protection is
entrusted to H.R.C. fuses that do not operate with currents within a limit
which the contactor can withstand but that, on the contrary, with higher
currents grant the full protection or a limited damage of the contactor itself.
The table below shows for the different types of contactor the corresponding
size of fuses recommended to obtain respectively the full protection or a
damage limited to the contacts' welding.
(Table n. 6)
| Contactor Type N |
|
85 |
125 |
190 |
270 |
350 |
550 |
650 |
800 |
1000 |
1250 |
| Max.Fuse |
c |
100 |
125 |
160 |
225 |
250 |
355 |
425 |
500 |
630 |
1000 |
Rating [Amps.] |
b |
125 |
160 |
200 |
300 |
355 |
500 |
630 |
800 |
1000 |
1200 |
|