RCD sockets (residual current device) are designed to protect from fatal electric shocks as it automatically switches off electricity when there is a fault. This potentially life-saving device protects against electrocution in instances where there is a bare wire, overheating or earth faults.These socket-outlets with an RCD built into them can be used in place of a standard socket-outlet. This type of RCD provides protection only to the person in contact with equipment, including its lead, plugged into the socket.Types of RCD Sockets Passive RCD: When power is lost due to a fault the RCD trips out and isolates the circuit it is protecting. Passive RCDs do not trip during power cuts, making them ideal for fridges and freezers and also for protecting remote/unmanned areas. They are also known as a Latching RCD. Active RCD: These trip out and isolate the circuit due to faults and also during power cuts. Active RCDs remain off until manually reset, making them ideal for rotating machinery such as power tools and garden tools. They are also known as a Non-Latching RCD.