What is the difference between over voltage relay and over current relay?

What is the difference between  over voltage relay and over current relay?
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1 Answer

Answer :

A: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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