The IET’s technical helpline receives a wide range of frequently asked questions. Here are just a few of the common questions received. Room containing a bath or shower

Next, screw the base of the junction box to the side of an adjacent joist, or to a batten nailed between joists. Then it’ll be within reach of the cut ends of the main cable. Step 5 If the faceplate is made of metal, cut a short length of earth core from 1.5 mm² cable and run it between the earth terminals of the faceplate and mounting box. Replace the faceplate. Step 4 A plate switch is allowed outside the zones of a bathroom. A switch must be suitable for the location. The cords of cord-operated switches are allowed in zones 1 and 2 and are recommended for bathrooms and shower rooms. Luminaires (light fittings)

Room containing a bath or shower

Yes, 230 V fittings may be installed above a shower or bath, but they must be at least IPX4. Extractor fans Are 230 V light fittings permitted above a shower or bath (zone 1) in a room containing a bath or shower? Where consumers tails are protected against fault current by the distributors cut-out, the method of installation, maximum length and minimum cross-sectional area (csa) of the tails must comply with the requirements of the distributor. All final circuits of the location comply with the requirements for automatic disconnection according to Regulation 411.3.2.

Regulation 411.3.1.1 states: “a circuit protective conductor shall be run to and terminated at each point in wiring and at each accessory except a lampholder having no exposed-conductive-parts and suspended from such a point.” See BS 7671 for more information. Steel wired armoured cables vi) A metal conduit, metallic cable management system or other enclosure or electrically continuous support system for conductors All extraneous-conductive-parts of the location are effectively connected to the protective equipotential bonding according to Regulation 411.3.1.2.Regulation 701.415.2 (last paragraph) allows supplementary bonding to be omitted where the location containing a bath or shower is in a building with a protective equipotential bonding system in accordance with Regulation 411.3.1.2 and provided all of the following conditions are met: Note: The designer will still need to determine if the armour is suitable to be used as a CPC. Meter tails Yes, a suitable 230 V extractor fan may be installed in zones 1 and 2, and outside the zones. If an extractor fan is installed in zone 1 or 2 it must be protected against the ingress of moisture to at least IPX4.