7.4.2 - Special requirements for saunas

If separated extra-low voltage (SELV) is used, protection against direct contact must be provided by:
1. - enclosures or barriers providing protection to IP24. This means protection against entry of human fingers and from splashing water, and
2. - insulation which will withstand a voltage of 500 V r.m.s. for one minute.

Some of the standard measures for protection against both direct and indirect contact must not be used in saunas. These are:
1. - obstacles,
2. - placing out of reach,
3. - non-conducting location, and
4. - earth free equipotential bonding.

All equipment must be protected to at least IP24, and no equipment other than the sauna heater may be installed in zone A. There must be no socket outlets in a sauna room, nor other switchgear which is not built into the sauna heater; lighting switches must be positioned outside the sauna room. As well as having no socket outlets within the sauna room, it is advisable not to install them close to the room at all, which could encourage the introduction of portable appliances. In the lower part of the room where it will not be so hot (zone B) there is no special requirement concerning the heat resistance of equipment. If installed in zone C, equipment must he suitable for operation at an ambient temperature of 125°C, and only luminaires, mounted so as to prevent them from overheating, are allowed in zone D. All wiring must be carried out with flexible cables or cords having 180°C rubber insulation complying with BS 6141: 1992, although where higher rated cables are required they may be 180°C rubber insulated to BS 6007. All wiring must be enclosed within insulated wiring enclosures such as plastic trunking.

There is no specific requirement to use RCD protection for sauna equipment, but where it is desired to do so, attention is drawn to the high leakage currents common with sauna heating elements, particularly when water is applied. The manufacturer should be consulted to ensure that leakage currents are unlikely to cause problems with an RCD rated at 30 mA. In some cases an RCD with a 100 mA rating may be more satisfactory.