Mini Circuit Breakers

Miniature circuit breakers (MCB) are electrical switches that are designed to trip during a short circuit or overload to protect against electrical faults and equipment failure. Overload protection is accomplished through a thermal operation with a slight time delay. When an overcurrent passes through an MCB, a bimetallic strip is heated and bends. The bending causes a mechanical latch to release, opening the MCB contacts, halting the flow of current. When the overcurrent is removed, the contacts close and the MCB is reset. Short circuit protection is accomplished through an electromagnetic operation that is instantaneous. A current coil is tripped causing the mechanical release of the latch that opens the contacts that halt the flow of current. When the overcurrent is removed, the MCB can be reset.

Miniature circuit breakers have a current rating less than 100 amps and have an interrupting rating less than 18,000 amps. They come in different types according to their tripping or overcurrent characteristics. The three main types, B, C and D can be selected based on their response to different electrical surges in different settings.

Type B trip if the current flowing through is between three and five times the recommended rated load. These are the most sensitive and are best for low voltage settings where current surges are likely to be small.

Type C trip if the current flowing through is between five and ten times the recommended rated load. These are best for industrial and commercial environments where surges are likely to be higher. 

Type D trip if the current flowing through is between ten and twenty times the recommended rated load. These are the least sensitive and are best for heavy-duty industrial and commercial devices where very strong surges occasionally occur.

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$1943.20
E-Frame Brkr 50A, 1P, 277V, 18/25kA, Bolt-on Mnt, 30mA, Alarm SW
$2090.20
E-Frame Brkr 30A, 1P, 277V, 35/65kA, Bolt-on Mnt, 30mA, Alarm SW
$1943.20
E-Frame Brkr 40A, 1P, 277V, 18/25kA, Bolt-on Mnt, 30mA, Alarm SW
$1943.20
E-Frame Brkr 20A, 1P, 277V, 18/25kA, Bolt-on Mnt, 30mA, Alarm SW
$1943.20
E-Frame Brkr 30A, 1P, 277V, 18/25kA, Bolt-on Mnt, 30mA, Alarm SW
$1267.00
E-Frame Brkr 30A, 1P, 277V, 18/25kA, Bolt-on Mnt, Shunt Trip
$1267.00
E-Frame Brkr 40A, 1P, 277V, 18/25kA, Bolt-on Mnt, Shunt Trip
$1267.00
E-Frame Brkr 50A, 1P, 277V, 18/25kA, Bolt-on Mnt, Shunt Trip
$1807.40
E-Frame Brkr 15A, 2P, 480Y/277V, 18/25kA, Bolt-on Mnt, Shunt Trip
$1073.82
MINIATURE CIRCUIT BREAKER 480Y/277V 20A
$900.20
E-Frame Brkr 20A, 2P, 480Y/277V, 18/25kA, Bolt-on Mnt, High Amp Lugs
$2115.40
E-Frame Brkr 70A, 2P, 480Y/277V, 18/25kA, Bolt-on Mnt, Shunt Trip
$1125.60
E-Frame Branch Brkr 25A, 2P, 600Y/347V, 14kA, Bolt-on Mnt
$1587.60
E-Frame Branch Brkr 70A, 2P, 600Y/347V, 14kA, Bolt-on Mnt
$1587.60
E-Frame Branch Brkr 90A, 2P, 600Y/347V, 14kA, Bolt-on Mnt
$1373.40
E-Frame Brkr 15A, 3P, 480Y/277V, 18/25kA, Bolt-on Mnt, Alarm/Aux SW
$1340.27
MINIATURE CIRCUIT BREAKER 480Y/277V 20A
$1340.27
MINIATURE CIRCUIT BREAKER 480Y/277V 25A
$2430.40
E-Frame Brkr 45A, 3P, 480Y/277V, 18/25kA, Bolt-on Mnt, Alarm/Aux SW, Shunt Trip