Owing to the increased risk of fatal electric shock owing to a person being unclothed and wet in a room containing a bathtub or shower basin the location is designated a special location.
This means that a bulk of electrical installation work in this location is also notifiable under Electrics:Part P of the building regulations in England and Wales.
All of the circuits in this location should be protected by a 30mA RCD.
Unlike the 16th edition, the 17th edition of the IEE regs allows normal socket outlets to be fitted in the location providing they are at least 3 meters horizontally away from the boundry of zone 1.
The requirements for supplementary bonding have been altered in the 17th edition regs, if certain requirements are met then supplementary bonding may be omitted all together. See Supplementary equipotential bonding (17th edn regulations)
The area around the bathtub or shower basin is designated a zone as follows:
Equipment to be IPX7 minimum.
Only SELV current using equipment is allowed with a maximum voltage of 12V AC(RMS) or 30V ripple free DC, the source fed from outside the zones.
No switchgear or accessories are allowed.
Equipment to be IPX4 minimum, IPX5 if water jets are used for cleaning.
Current using equipment may be installed providing it is 25V AC (RMS) maximum or 60V DC SLEV or PELV, the source being installed outside the zones. Items such as whirlpool units, showers, pumps, fans, towel rails, water heaters and light fittings may also be installed, see the manufacturers instructions.
Only switchgear with a maximum 12V AC RMS or 30V DC SELV may be installed, the source being outside the zones. This doesn’t apply to switches inside current using equipment.
Equipment to be IPX4 minimum, IPX5 if water jets are used for cleaning.
Fixed permanently connected equipment allowed, the general requirements of the regulations apply to this part of the room, all items within the location must be suitable for where they are installed.
Only switchgear or accessories fed from a SELV source fitted, the source being outside the zones. A shaver socket with isolating transformer (BS EN 61558-2-5) may be fitted as long as it can’t be affected by a direct spray.
A socket outlet may be installed providing it is at least 3 metres away horizontally away from the edge of zone 1.
The general requirements of the regulations apply to this part of the room, all items within the location must be suitable for where they are installed.
A handy interactive guide courtesy of Mr Resistor:
http://www.mr-resistor.co.uk/default.aspx?pageid=1079
The Building Regulations require certain electrical work to be notified, including anything done in any of the numbered Zones in a bathroom.
Please refer to the Wiki article on Part P for full information on what work is notifiable.
