An RCCB or residual-current circuit breaker is a safety device used to protect electrical circuits. RCCBs protect people from electric shocks, and electrocution and help prevent electrical fires.

RS offers an extensive range of high-performance RCCBs and RCDs from leading brands including ABB, Schneider Electric, and Siemens.

How does an RCCB work?

An RCCBs incoming current must equal the outgoing current in any circuit. RCCBs can compare the difference in current values between the live and neutral wires. When appliances are working correctly all current entering the appliance through the live wire leaves the appliance via the neutral wire. If a fault occurs some current can flow through the earth wire if there is no earth this can even flow through you. This results in the unequal current flow coming into the device to what is going out, this difference is referred to as residual current.

What is the difference between an RCCB and an RCD?

An RCD (residual current device) can keep an electrical system safe by preventing fatal electrical shocks. RCDs can also provide protection from electrical fires. An RCCB is essentially an RCD minus the overload protection. They are typically used in applications where the risk of electric shock is limited. For more detailed information, please see our in-depth RCDs guide.

What are the different types of RCCB and RCD?

RCCBs and RCDs are usually mounted on DIN rail. They can be 2, 3, or 4 poles. Varying in current ratings, trip sensitivity, and tripping characteristics. All these specifications should be carefully considered depending on your individual needs and application.