What is the difference between Relay,Circuit Breaker,Isolator?
Relay is a protective device which senses the faulty conditions in
a power system line and initiates the operation of circuit breaker to
isolate the faulty part from the rest of the healthy power
system.Examples of relays are Over Current relay,Directional relay,etc..
Circuit Breaker is a device which can
- Make or break circuit under normal conditions either manually or through remote control.
- Break circuit automatically under faulty conditions.
- Make or break circuit under faulty conditions either manually or through remote control.
Some
types of circuit breakers are Air blast circuit breakers,Vaccum Circuit
Breakers ,SF6 Circuit Breakers,etc.You can notice the circuit breakers
near to the transformers.Next time when you see a transformer search for
the circuit breaker.Mostly it will be SF6 Circuit Breakers.
Isolator or Isolating Switch is a device which is used to disconnect a part of the system for maintanance purpose and repairs.Isolator can open a circuit under no load condition only.If
two isolators are connected on either sides of circuit breaker,then the
circuit breaker must be opened before opening the isolators.
After
perfoming maitanancee work on the circuit breaker,isolators must be
closed first and then the circuit breaker must be closed to bring the
system into operation.
