Sockets and switches

A domestic socket is rated 16 A and 250 V — the standard for socket circuits. High-power appliances (a hob, an instant water heater) get their own circuit and, if needed, a higher-current socket.

An earthed socket (third contact) is mandatory for appliances with a metal body: washing and dishwashing machines, a water heater, a fridge, a computer. Earthing carries the potential off the body and protects the person if the insulation fails.

Don't run heavy appliances through splitters and extension leads: what overloads is the wire and breaker, not the socket. Give high-power loads their own circuit from the board.

A two-way switch controls one light from two or more places — for instance, on at the bottom of the stairs and off at the top, or at the bedroom door and by the bed. You wire two (or more) two-way switches onto one circuit.

A dimmer smoothly adjusts brightness. Important: the dimmer and the fixture must be compatible. Not every LED fixture dims, and not every dimmer works with LEDs — look for a "dimmable" mark on the fixture and a matching dimmer type.

Plan the scenarios in advance: where you need control from two points, where brightness control. Redoing it after the finish is expensive.

In a bathroom, at a kitchen sink and outdoors, sockets and switches must be rated (usually IP44 or higher) and have a cover. A plain IP20 socket in a wet zone is dangerous.

Bathrooms follow zoning: no sockets right by the bath or shower — they go further away and are protected by a 30 mA RCD (or 10 mA for the wettest zones). An RCD cuts the circuit on a current leak — this is the protection against electric shock specifically.

Outdoors, use sealed sockets and frames with a gasket and cover, rated for temperature swings.