Why dc supply is used for closing and tripping coil of ht
breakers. What happen if we use only ups ac supply only.

Answer Posted / kesavan.03

In the case of AC supply we can't reliable. However UPS is
available in any failure of UPS supply also will dangerous
for control system. As in the case of DC supply the battery
is charged & it is available whenever we need. So DC coils
are used for control purpose(Closing & Tripping),

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1988