Molded Case Circuit Breakers

A molded case circuit breaker (MCCB) is a low-voltage circuit breaker that provides overload and short-circuit protection together in a molded insulating housing. It is used at the incomers and outgoings of main and sub-distribution panels, at generator outputs and on machine supplies to protect and switch the line. The category includes Schneider Electric, ABB and Siemens models in rated currents such as 63 A, 160 A, 250 A and 630 A, 3- and 4-pole, with thermal-magnetic or electronic trip units; breaking capacities are in values such as 25 kA, 36 kA and 50 kA. Choose the rated current and thermal setting range according to the load current, the short-circuit breaking capacity (Icu) according to the short-circuit current at the installation point, and the number of poles according to the network structure; also compare the trip unit type. Icu depends on voltage; among the values given separately in the technical table for voltages such as 415 V and 690 V, rely on the one for your operating voltage. A molded case circuit breaker should not be confused with a miniature circuit breaker (MCB): a miniature circuit breaker is a modular breaker whose tripping threshold cannot be adjusted and that generally has a lower breaking capacity.

Products

How to choose Molded Case Circuit Breakers

A molded case circuit breaker (MCCB) is a low-voltage circuit breaker that provides overload and short-circuit protection together in a molded insulating housing. It is used at the incomers and outgoings of main and sub-distribution panels, at generator outputs and on machine supplies to protect and switch the line.

  • Separate overcurrent/leakage protection, motor starting and local isolation requirements.
  • Select rated current, pole count and breaking capacity (kA) from the installation calculation.
  • Match coil voltage, auxiliary contacts and tripping curve to the control circuit and load type.

Frequently asked questions

What is Molded Case Circuit Breakers and where is it used?

A molded case circuit breaker (MCCB) is a low-voltage circuit breaker that provides overload and short-circuit protection together in a molded insulating housing. It is used at the incomers and outgoings of main and sub-distribution panels, at generator outputs and on machine supplies to protect and switch the line.

What should I compare when choosing Molded Case Circuit Breakers?

Choose the rated current and thermal setting range according to the load current, the short-circuit breaking capacity (Icu) according to the short-circuit current at the installation point, and the number of poles according to the network structure; also compare the trip unit type.

Where can I find technical details for Molded Case Circuit Breakers products?

A molded case circuit breaker should not be confused with a miniature circuit breaker (MCB): a miniature circuit breaker is a modular breaker whose tripping threshold cannot be adjusted

Molded Case Circuit Breakers (MCCB) Selection Guide