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All final circuits of the location have additional protection by means of an RCD in accordance with Regulation 701.411.3.3. All extraneous-conductive-parts of the location are effectively connected to the protective equipotential bonding according to Regulation 411.3.1.2. 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 An extractor fan supplied from a lighting circuit for a bathroom without a window should have its own means of isolation, as otherwise replacement or maintenance of the fan would have to be carried out in the dark. An isolation switch for a fan with an overrun facility will need to be triple-pole (switch wire, line and neutral), and must be installed outside zones 0, 1 and 2. Supplementary bonding
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 All final circuits of the location comply with the requirements for automatic disconnection according to Regulation 411.3.2. 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) Yes, 230 V fittings may be installed above a shower or bath, but they must be at least IPX4. Extractor fans 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.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 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 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: 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. Note: The designer will still need to determine if the armour is suitable to be used as a CPC. Meter tails
Are 230 V light fittings permitted above a shower or bath (zone 1) in a room containing a bath or shower? Buried cables, conduits and ducts shall be at sufficient depth to avoid being damaged by any reasonably foreseeable disturbance of the ground. A depth of less than 0.5 m is usually inadvisable. See Regulation 522.8.10 of BS 7671 for more information. Earthing at lighting points vi) A metal conduit, metallic cable management system or other enclosure or electrically continuous support system for conductors