Explen all type electrical protection ? like
O/C,E/F,NPS,VOLTAGE UN BLANCE,CURRENT UN BALANCE,NAGETIVE
PHASE SEQ,AND ETC...............electrical Protection

Answer Posted / sgthakur

o/c prot. means in simple lang.to protect elect.equip.from
being over loaded whether it is in one/two phase.
E/F prot is provided in mainly capital equip.to protect
fr.damage in the winding during insulation failure.
Neg.phase seq. provided to such costly HT motor to protect
fr. serios damage in the elect. equip.due to unbalance in
the system causes tremendous heating in the winding thus
puncture the insulation.
In delta-delta system where neutral earthing is not
available, there to obtain extra neutral earth zig-zag
trans is used for E/F prot.

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