TERM RELATED TO CIRCUIT BREAKER

 TERM RELATED TO 11 KV CIRCUIT BREAKER RATING:

1.RATED VOLTAGE: It is the maximum rms voltage on which circuit breaker can works normally.

 ex: Rated voltage: 12 KV means circuit breaker works normally up to 12 KVrms voltage.

2.RATED CURRENT: It is the maximum rms current on which circuit breaker can works normally.

ex: Rated current: 630 A means circuit breaker can work normally up to 630 A.

3.RATED FREQUENCY: Rated frequency of a circuit breaker is the frequency at which it is designed to operate.

ex: Rated frequency: 50 Hz

4.PF WITHSTAND VOLTAGE: It is the rms value of sinusoidal power frequency voltage that the electrical equipment shall withstand for a specific period of time normally 01 minute.

ex: PF withstand voltage: 28 KVrms

5.SHORT TIME CURRENT: It is the ability of circuit breaker to withstand for a short time duration under high fault condition.

ex: 25 kA for 3 sec means this circuit breaker withstand for 3 sec up to 25 kA high fault current.

6.IMPULSE WITH STAND VOLTAGE: It is the peak value of impulse voltage (lighting, over voltage) on which circuit breaker capable of withstand without failure.

ex: Impulse withstand voltage: 75 kVp

7.MAKING CAPACITY: It is the maximum peak value of the current that the circuit breaker can interrupt without any damage if the breaker is closed at fault.

Making current > Breaking current

Making current = 2.55*symmetrical breaking current

ex: Making capacity: 62.5 kA

8.SYM. BREAKING CAPACITY: It is the level of current at which the circuit breaker can interrupt without any damage.

Breaking current = 1.8*1.41*Irms

Rating plate circuit breaker

ex: Sym. breaking capacity: 25 kA

9.MOTOR SUPPLY: It is the voltage at which spring charging motor of circuit breaker work.

ex: 240V AC

10.SHUNT TRIP/CLOSE COIL: It is the voltage at which circuit breaker shunt trip/close coil works.

ex: 220V DC

11.BUS BAR RATING: It is the maximum value of bus bar current on which circuit breaker connected.

ex: 1250 A

12.SERIAL NO.: It is used by manufacture for identity.

Important links:

Accessories at circuit breaker panel?

Operating duty of circuit breaker?