Answer / nithi

NO.We can't sense the over voltage by just measuring the
current only.because,
The current increases not only for over voltages but
also for under voltage(As most of the loads are non-linear
in nature).
So,the over voltage protection & over current
protection are completely different.

over voltage relay meant for sensing over voltages &
protect the system from insulation break down and firing.

over current relay meant for sensing any internal
short circuit,over load condition ,earth fault thereby
reducing the system failure & risk of fire.

So, for a better protection of the system,It should have
both over voltage & over current relay.

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