RCDs are designed to disconnect the conducting wires ("trip") quickly enough to potentially prevent serious injury to humans, and to prevent damage to electrical devices. A two-pole, or double-pole, residual-current device. The test button and connect/disconnect switch are colored blue.OverviewA residual-current device (RCD), residual-current circuit breaker (RCCB) or ground fault circuit interrupter (GFCI) is an. RCDs are designed to disconnect the circuit if there is a leakage current. In their first implementation in the 1950s, power companies used them to prevent electricity theft where consumers grounded returning circuits rath. with incorporated RCD are sometimes installed on appliances that might be considered to pose a particular safety hazard, for example long extension leads, which might be used outdoors, or garden equ.
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