The overcurrent relays are connected in series to the load circuit and the load current is passed through.
Current relay circuit.
Split core current sensor relays can help monitor the current of circuits to help in detecting locked rotors current loss open heaters or lamp loads.
The operating circuit circuit 1 see the figure 1 is connected to a solenoid coil wound round iron core.
If trip coil of breaker fails then tripping of breaker will not take place.
Internal core current sensor relays internal core current sensor relays are designed to help monitor the current flow in a conductor.
When a pump is operated with a flooded suction and liquid completely covers its inlet the pump s motor will draw normal operating current.
In the overcurrent relays the current is set by the adjusting screw on the relay.
The current sensing relay in this water pump electrical circuit prevents the pump from running when the water level is too low.
The current is set within certain limits according to rated currents of the motors.
Medium current relays these relays are rated for motors with 1 3 horsepower or 15 90 amps use them with industrial automation systems security and emergency lighting and small motors.
A relay is a device by which electric current flowing in one circuit can open or close a second circuit i e.
Under normal condition the current through the relay coil is not sufficient enough to pull the plunger and close the circuit of breaker tripping coil.
Notice here that breaker tripping coil is solely responsible for the tripping of circuit breaker.
The overcurrent relays connected to the three phase conductors only control one relay in one phase alternating current circuits and the three phase conductors control the normally closed contact in the control circuit.
Switch the current on or off in the second circuit.