RCD

RCD (protective device)

— automatic devices that react to the appearance of the so-called leakage current. Such a current occurs, in particular, in case of short circuits to the ground or the housing, as well as when a person accidentally touches live parts (or the housing of a faulty electrical appliance that is energized due to a malfunction in the device). When a leakage current occurs, the RCD turns off the power to the network. Thus, such devices provide protection not only from breakdowns and fires, but also from electric shock.

Do not confuse RCDs with circuit breakers (see the relevant paragraph). Unlike circuit breakers, RCDs do not react to increased current and are not able to protect the system from overloads and short circuits. Thus, the protection device must only be connected in combination with a circuit breaker (in series).