On-Site Guide (BS 7671:2018+A2:2022) (Electrical Regulations)

Product Information

vi) A metal conduit, metallic cable management system or other enclosure or electrically continuous support system for conductors For TT systems the figures for TN-C-S systems, with RCDs, may be used provided that: (a) the circuit is protected by an RCD to BS 4293, BS EN 61008, BS EN 61009

Maximum diameter of hole should be 0.25 x joist depth. Holes on centre line in a zone between 0.25 and 0.4 x span. Maximum depth of notch should be 0.125 x joist depth. Notches on top in a zone between 0.07 and 0.25 x span. Holes in the same joist should be at least 3 diameters apart. The distributor needs to be consulted as to the prospective fault current at the origin of the installation. Except for London and some other major city centres, the maximum fault current for 230 V single-phase supplies up to 100 A will not exceed 16 kA. In general, the fault current is unlikely to exceed 16.5 kA. is the maximum fault current the breaker can interrupt safely, although the breaker may no longer be usable. les is the maximum fault current the breaker can interrupt safely without loss of performance. lenPersons carrying out electrical work in dwellings must comply with the Building Regulations of England, in particular Part P (Electrical safety - dwellings). Persons responsible for work within the scope of Part P of the Building Regulations may also be responsible for ensuring compliance with other Parts of the Building Regulations, where relevant, particularly if there are no other parties involved with the work. Building Regulations requirements relevant to installers carrying out electrical work include:

Where these spacing requirements are impracticable the pipework should either be sheathed with an electric insulating material rated at 230 V or more, or a panel of electrical insulating material should be interposed. Refer to the lET publication Electrician's Guide to the Building Regulations for more indepth guidance on electrical installations in dwellings. Note: The designer will still need to determine if the armour is suitable to be used as a CPC. Meter tails Also taken into consideration is the temperature of the area or void, the length of the cable run, the grouping of the points they serve and the type of device (Fuse, RCD etc.) by which they are protected. For details of these changes please see the link to the Institute of Electrical Engineers. In essence, for domestic use, the cable wire colours will change to those of standard electrical flex colours.Eledricity meter The terminals will be sealed by the meter owner to prevent interference by unauthorised persons. i) be protected by a 30 mA RCD and, if they are at a buried depth of less than 50 mm, be installed as (b), or (ii) be installed as (c), (d), (e) or (f). ~ Figure 7.3.2 The general layout of the equipment at the service position is shown in Figures 2.1 (i) to 2.1(iii), including typical protective conductor cross-sectional areas. The following scenarios are considered: . ,._ Figure 2.1 (i) TN-C-S (PME) earthing arrangement . ,._ Figure 2.1 (ii) TN-S earthing arrangement (cable sheath earth) . ,._ Figure 2.1 (iii) TT earthing arrangement (no distributor's earth provided/used) BS 7671:2018 does not specify requirements for protection against transient overvoltages due to direct or nearby lightning strokes on the structure. For risk management for protection against transient overvoltages due to direct or nearby lightning strokes on the structure, see BS EN 62305-2. The lET's Wiring Regulations Policy Committee, therefore, advises the following: A Class I metal consumer unit is installed and each outgoing circuit is protected by an RCBO (b) A split, Class I metal consumer unit is installed, where the double-pole main switch of the consumer unit should incorporate an S type (time delayed) RCCB, e.g. 100 mA S-type R CCB.

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) All extraneous-conductive-parts of the location are effectively connected to the protective equipotential bonding according to Regulation 411.3.1.2. including the distributor's equipment and metering equipment (b) the existing equipment is suitable for continued use, including the distributor's equipment and metering equipment (c) earthing and bonding arrangements, if necessary for the protective measure applied to the addition or alteration, are adequate Where the work is an addition to an existing circuit, the designer/installer takes responsibility for the circuit, so far as is reasonably practicable, in addition to the items a - c above, not just the not just the small addition or alteration they are undertaking. There is no difference as to whether the addition or alteration is temporary or permanent, electricity and compliance with BS 7671 must be ensured in all circumstances. Consumer units in dwellings

Electrician’s Guide to the Building Regulations, 6th Edition

If buried, generator reference earthing and/or bonding conductors should be sized in accordance with Table 54.1 and suitably protected in accordance with Regulation 2 543.3.1 . For example, a 16 mm conductor would generally be adequate for short-term use where no mechanical protection is provided. Please, if you are doing and electrical work, make sure you have the right VDE approved tools for the job and do not be tempted to save money by buying cheap imitations which will not be anywhere near as well insulated.