Installing or fitting an electric cooker must be done on its own circuit. An electric cooker cannot be spurred of any other circuit and must be controlled by its own fuse at the consumer unit. For this reason, if this is a new installation it counts as installing a new circuit and is forbidden by any other than a Part P qualified electrician. Please see our project on part P if you do not understand this.
Connecting a cooker cable to the mains is the last part of this project. If connecting a cooker - the appropriate fuse should be withdrawn.
Electric cookers draw huge amounts of current because of the heat they need to produce so a larger fuse is required as is thicker cable and a double pole isolating switch. Usually when a switch is installed it interrupts the live wire of the circuit. The switch breaks the connection in the live wire. With a double pole switch the connection to the live and the neutral is broken so there is no fear of any residual current causing a shock when the switch is off.
Because the cooker is on its own circuit the cable comes from the consumer unit, via a switch, to the cooker. Because of the current the cooker draws the cable is not run back to the consumer unit as in a ring main, so the cooker circuit is on a radial circuit.
The cooker must be connected to a cooker control unit, left. It must be connected via the correct size cable and this may vary but is directly related to the power of the cooker. See our table on cable sizes and check the rating of your cooker. The cooker control unit fits to a patress box, just like a socket outlet or switch and may be flush or surface mounted. Some cooker control units (See images) offer simple switching facilities but others include a socket. If a 13amp socket is included an additional demand of 5 amps is placed on the circuit and your cable and switches must reflect this increse. Cooker control units also come with neon lights to signify that the unit and/or switch is turned on and the current is reaching the unit.
The incoming mains is wired into this cooker control switch which ideally will be sited to one side of the cooker (so you do not have to lean over the cooker to turn on and off) and about 300mm above the worktop. Feed the circuit cable into the control unit. Strip and prepare the ends of the cable. The cooker control unit has two separate sets of connectors and terminals. The incoming mains goes into the terminals marked mains and the outgoing cable is connected to the load terminals. The load cable then runs to the terminal outlet box (or cooker outlet box) which is simply a junction box in the wall where the cooker cable is connected to the mains cable you have just installed. The terminal outlet box is covered with a plate which allows easy, but safe access for connection. It is usual to place this terminal outlet behind the cooker itself about midway up its height.
When all other connections are made connect your cable to the mains and fit the correct sized fuse. See our project on amps, volts and Watts to work out the correct size fuse for your cooker and other circuits.