Answer / amit rajak

contactor- it is simply a switch or combination of switch
which is used to open or closed the circuit having
different phase wire in single phase circuit or three phase
circuit by automatic that is by pneumatic ( by air ) or
also manually.


relay -it is a protecting device that is used to protect
the circuit from faults.
it is basically a sensor which senses the fault in
electrical circuit having different parameters .it ihas a
predetermined set parameter which makes comparision under
fault condition and provides the initial signal to the
circuit breaker which fif finds the parameter more than
the predetermined magnitude or value it trips the circuit
examples of relays are:
1).electromagnetic relays
2).thermal relays
3).induction relays
4).differential relays
5).distace relays

few modification are used in these relays to suite certain
operation.

Answer / guest

relay is act as a electromagnetic switch conductor is copper
strip

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