Explain the construction and working of electronic overload relay.

1 Answer

Answer :

Electronic overload relay consists of a solid state circuit that operates the electromagnetic switching device to protect the load from overload. The load current is sensed by using a current transducer such as current transformer. The output of current transformer is converted to voltage signal as required by the electronic circuit. The electronic circuit consists of RMS-to-DC conversion, threshold detection, time setting and relay driver sections. The output of relay driver section sends trip signal to electromagnetic switching device.

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