Over current relays are divided into two according to the structures.
Over current relay circuit diagram.
2 no o c relay 1 no e f relay for over current and earth fault protection.
In addition a thermal magnetic circuit breaker is used for both overcurrent and overload protection.
The two over current relays in r and b phases will respond to phase faults.
It protects the equipment of the power system from the fault current.
Depending on the time of operation the overcurrent relay is categorized into following types.
Double click the block.
At least one relay will operate for fault involving two phase.
Working principle of over current relay.
Since the normally closed contact is empty the led is off when there is no.
In an over current relay or o c relay the actuating quantity is only current there is only one current operated element in the relay no voltage coil etc.
A new window will open.
Circuit diagram of instantaneous overcurrent relay in simulink.
Fuses circuit breakers overcurrent relays current limiters temperature sensors and solid state power switches are used against overcurrent protection devices.
Earthing of both will short circuit the e l relay and make it inoperative for faults.
With the circuit shown in figure 1 7 led1 can be switched off by relay and button control.
It is not present in simulink library so follow the steps given below.
Draw the following circuit diagram in the newly opened window.
Thermal overcurrent relay magnetic overcurrent relay.
Take the subsystem block from commonly used blocks.
Overcurrent relay has the in matlab.