Miniature Circuit Breakers (MCBs)

Techna offer a wide range of 6kA and 10kA Miniature Circuit Breakers (MCBs) available in 1 to 4 pole, in current ratings from 0.5A to 63A and in various trip curves. For more demanding applications we offer high current versions in current ratings from 80A to 125A. Add-on accessories, such as auxiliary contacts, are also available.

Our range of MCBs are suitable for mounting on DIN-Rail and can be used inside our Dtec Distribution Boxes and WINtec IP67 Protection Windows.

What is a Miniature Circuit Breaker (MCB)?

A Miniature Circuit Breaker (MCB) is an electro-mechanical device which automatically switches off the electrical circuit flow should a fault occur, through short circuit or overload of the circuit.

The MCB, an automatically operated electrical switch, is designed to protect a low voltage electrical circuit from damage due to a fault. Once a fault is detected, the copper (or other highly conductive material) contacts within the MCB open in order to interrupt the circuit, this is generally done by using mechanically stored energy contained within the breaker.

A MCB is the preferred device for domestic household and industrial circuits and is now used instead of a fuse. It is quick and easy to operate, safe to handle, no maintenance cost and can be easily reset and power restored by the flick of a switch.

By cutting the circuit quickly in a household or industrial building can prevent electrical or fire hazards.

How does a Miniature Circuit Breaker (MCB) work?

The MCB switch will kick in and automatically switch off the power supply when the circuit is overloaded, if too many devices are being operated at the same time or if there is a short circuit.

The MCB is designed to track changes in temperature in its operating environment and this will affect the breaker’s current capacity. This is desirable as the cables being protected also perform differently in different ambient temperatures.