Different protection methods of electrical equipment?

Electrical Equipment Protection

There are are three basic approaches protection.

Protection by a fuse - Short circuit,Earth faults, and overloads.

Protection using releases integrated with circuit breakers - Short circuits,overloads and earth faults.

Protection using relays and circuits.

Fuse application

Steady loads - Normally protect against over load as well as short circuit.

Fluctuating load - Eg: DOL motors with high inrush compared to normal rating. Here fuses generally protect against short circuit only.

Circuit Breakers Fuses act as fault current sensors and interrupters.

Other approaches use a circuit breaker to interrupt short circuit/earth fault.

Circuit Breaker with Release

Integrated protection-independent,self-actuating.


Basic Types of relay

Electromagnetic relay Static relay

All explained in easily . Thanks a lot