Residual Current Circuit Breakers (RCCBs)

Techna offer a wide range of 6kA and 10kA Residual Current Circuit Breakers (RCCBs), also known as Residual Current Devices (RCDs), available in 2 or 4 pole, in current ratings from 25A to 125A, with residual current sensitivity from 10mA to 500mA and with inbuilt test buttons. Low voltage (LV) versions are also available, which have been designed to be used on 110V systems.

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

What is a Residual Current Circuit Breaker (RCCB)?

A Residual Current Circuit Breaker (RCCB) provides protection against residual current faults, most commonly referred to as earth leaks or ground faults (in the USA). However, RCCBs can also be used to protect three phase systems where the current leakage fault may be to earth but could also be between live phases.

An RCCB only protects against residual current faults, not overcurrent or short circuit faults, and should therefore be used in conjunction with one or more Miniature Circuit Breakers (MCBs).

The residual current sensitivity is the key parameter when specifying an RCCB and defines the fault level you want the RCCB to detect and protect against, with 30mA being the most common in the UK and Europe.

A Residual Current Circuit Breaker (RCCB) also has a main current rating, which is usually from 25A to 63A. It is critical to understand this is nothing to do with its protection capabilities and simply states the maximum continuous circuit current the RCCB can carry under normal working conditions. So, for example, you could use a single 40A RCCB to provide residual current fault protection for 4 x 10A separate miniature circuit breaker circuits.

Both 6kA and 10kA short circuit ratings are available. This describes the maximum short circuit the RCCB can withstand and still be resettable. However, this rating is applicable only when used in conjunction with an appropriate MCB or fuse.

The RCCB device will detect and trip against electrical leakage currents, so providing protection against electric shock caused by indirect contacts.