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CASEY EQUIPMENT CORPORATION
275 KAPPA DRIVE
PITTSBURGH, PA 15238
PHONE: (412) 963-1111
 

Equipment   >   Electrical

circuit breakers
 

Circuit Breakers

CIRCUIT BREAKERS (DC) (17)

CIRCUIT BREAKERS 2300V & ABOVE (84)

CIRCUIT BREAKERS (GAS) (3)

CIRCUIT BREAKERS 600V & BELOW (126)

 

There are two different types of circuit breakers, air circuit breakers and vacuum circuit breakers. An air circuit breaker extinguishes the arc that is formed when a load is interrupted. A vacuum circuit breaker maintains a vacuum in the arc space, where the arc is extinguished.

High voltage circuit breakers have voltage greater than 7200 volts.

Medium voltage circuit breakers have voltage from 1000 to 7200 volts.

Low voltage circuit breakers are rated less than 1000 volts.

Breakers are opened by a charging spring. This is a powerful spring that gives a fast breaker opening time to minimize arc formation and prevent damage to downstream components. If the breaker is experiencing a fault signal, a small gear, motor compresses the spring after the breaker is closed. It is activated by relays that change state with the position of breaker. If a short circuit does occur, it is important the fault current does not exceed its interrupting capacity which is the current the circuit breaker can safely interrupt. Circuit breakers are designed to be used over and over again, so if a circuit is properly designed, fault current should not destroy the breaker.

The interrupting capacity of a circuit breaker required to protect a circuit can be calculated by measuring the output voltage of the circuit at no load and full load. If the current flowing through the circuit is known, the resistance of the circuit and its current carrying capacity can be calculated using Ohm's law. Casey has the following vacuum and air circuit breaker elements in stock for spares or in switchgear for expansion projects:

5 KV GE Power/VAC VB1-4.16

7.2 KV GE Power/VAC VB1-7.2

5 KV Siemens Vacuum Breakers 5GMI-350

38 KV Siemens Vacuum Breakers 38-3AF-31-200-85600V

GE AKD8 Air Circuit Breakers Type AKR-7D-75H AND AKR-7D-50H

600 V GE Air Circuit Breakers Type AK-1-15, AK-1-25, AK-1-50, AK-2-25, AK2-50, AK2A-50-1, AKR-7D-50

600 V Siemens Type RL Air Circuit Breakers RL4200, RL3200, RL2000 AND RL1600

600 V Westinghouse/Square D Type DS Air Circuit Breakers DS632, DS416, DS208

600 V Westinghouse Air Circuit Breakers Type DB-25, DB-50, DB-75

600 V Federal Pacific Air Circuit Breakers Type 50H2 and 75H3

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