Electrical Definitions

Bonding – A way of reducing the risk of getting an electrical shock.

Conductors – Wires that carry electricity.

Consumer unit – A fusebox that controls and distributes electricity around the home. It usually contains a main switch, fuses or circuit-breakers and may contain one or more residual current devices (see RCD).

Current – Flowing electricity.

Earth – A connection to the ground.

Earthing – A way of preventing electric shocks.

Electrical installation – A fixed wiring system.

Live – Active (there is electricity).

Main bonding – Green-and-yellow conductors that connect the hard metal pipework (gas, water or oil) from inside a building to the main earthing terminal of the electrical installation. Main bonding connections may also be made outside the building, for example where a semi-enclosed gas meter box is installed outside and it is not possible to install a bond to the gas installation pipework indoors.

Main earthing terminal – A terminal block where earthing and bonding conductors are connected together.

Residual current device (RCD) – An RCD, or residual current device, is a life-saving device which is designed to prevent you from getting a fatal electric shock if you touch something live, such as a bare wire. It can also provide some protection against electrical fires. RCDs offer a level of personal protection
that ordinary fuses and circuit-breakers cannot provide.

Supplementary bonding – Green-andyellow conductors that connect the earthing terminals of electrical equipment (such as lighting points and electric showers) to accessible metal parts of items of electrical
equipment and/or accessible metal parts of items that are not electrical (such as pipes). These connections are made to prevent a dangerous voltage occurring between two accessible metal parts, in the event of a fault.

Voltage – The force of electricity