Selection and Erection – Equipment
Regulation 537.5.4.3, whilst not new, is not always complied with and states that where the direction of rotation is a factor relating to safety, measures to prevent the reversal shall be taken. This effectively means supply phase rotation sensing at or near the motor with associated automatic isolation should phase reversal occur.
D 11 Plugs and socket outlets Regulation group 553 sets out the requirements for plugs, socket outlets and cable couplers in terms of applicable product standards, other particular requirements relating to pin configuration and the need for every socket outlet for household use to be shuttered. Except for the connection of clocks, electric shavers and other circuits having special characteristics (see Regulation 553.1.5), the only acceptable types of socket outlet for low voltage applications are:
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13 A plugs and socket outlets to British Standard BS 1363 for a.c. only; 2, 5, 15, 30 A fused or non-fused plugs, and socket outlets to BS 546; 5, 15, 30 A fused or non-fused plugs, and socket outlets to BS 196; 16, 32, 63, 125 A plugs and socket outlets (industrial type) to BS EN 60309–2.
There are many applications where you may wish, or indeed need, to specify or use a plug and socket not listed above. These will generally be ‘no-load’ makeor-break devices, and are fine for applications where skilled or instructed persons operate. The mounting height of a socket outlet above floor level, or above a work surface, should minimize the risk of accessory or cord damage (553.1.6). Although not specified as a distance in the Regulations, a height of approximately 150 mm above the floor or work surface is recommended as a minimum. For installations in domestic premises, Part M of the Building Regulations stipulates mounting heights for electrical equipment including socket outlets (see also BS 8300: Design of buildings and their approaches to meet the needs of disabled people. Code of practice). There has been some confusion with the interpretation of these requirements since their publication. Generally, for both dwellings and ‘visitor’ areas in commercial installations, electrical accessories should be mounted at a height of between 450 mm and 1200 mm above finished floor level. The basis of these criteria is to avoid problems for disabled persons that may visit a building. It is
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