Yellow wires are used as ceiling fan switches, structural lights and sockets combined with light switches, while blue wires are usually used as travellers for three- or four-way switches.

The cable C, the common cable, allows the continuous flow of the energy thermostat al 24 VAC. If your system does not have a cable C, you will have to run a new cable from your oven thermostat al to install more modern models of intelligent thermostat.

Red wires are used to designate hot wires. Red wires are sometimes used as the second hot wires in 240 volt installations. Another useful application for red wires is to interconnect smoke detectors with wires so that, if an alarm is activated all other detonators simultaneously.

The term earth means a connection with the earth, which acts as a cargo tank. An earth wire provides a path to the earth that is independent of the normal channel of current transport on an electrical device. This protects from electrical discharges.

Simply, the AWG or the American cable meter is the standard system that determines a cross section of a cable using a solid meter, round electrical cables. The greater the number of AWG, the smaller or thinner the cable. Used since 1857, AWG helped the user determine a wireless that carries the current ratings.