Because in CB there exist two trip coil... And in CRP there exist two main relay for voltage level 66 KV and above i.e. Main-1 distance relay and Main-2 distance relay .. therefore separate DC supply are given for main-1 and Tc-1 and main-2 and Tc-2 because failure of one DC will not impact relay and cb operation during fault condition.
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Sir,
Which make DC selection switch available in the market
Why required double DC supply or separate DC for CRP
Because in CB there exist two trip coil... And in CRP there exist two main relay for voltage level 66 KV and above i.e. Main-1 distance relay and Main-2 distance relay .. therefore separate DC supply are given for main-1 and Tc-1 and main-2 and Tc-2 because failure of one DC will not impact relay and cb operation during fault condition.
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@@relayprotectionelectrical what have position of DC selection switch in normal condition if both DC source available?
Independent..........?
Yes you have given the answer