UK Rules That Affect Your Bathroom Light
As mentioned elsewhere on this site the bathroom lighting is subject to the wiring regulations, BS7671 and these must be applied to any electrical installation
For the layman the wiring regulations are a minefield of confusing terms and even for an electrician they can be somewhat confounding.
The bathroom light is situated in what is deemed to be a special location, ie one that contains a bath or shower. Everyone will understand that where you have electricity and an abundance of water there will be an element of increased danger and this is why the regulations are very specific as to what is considered safe.
The bathroom, for the purposes of the wiring regs, is divided up into zones which are 0, 1,2 and ‘outside zones.’ The outside zones is basically any part of the bathroom which does not fall into zones 0,1 or 2.
Zone 0 is defined as any area within the bath tub or shower tray and only certain equipment can be installed here. For the technically minded, equipment which is 12V ac or 30V ripple free DC safety exta low voltage with the safety source outside the zones. All equipment must be IPX7.
Zone 1 is the area which is vertically defined by the edges of the bath or shower to a height of 2.25 metres. Equipment must be IPX4 rated or IPX5 if jets are used. Some mains equipment is allowed in this area such as electric showers, whirlpool equipment, shower pumps and luminaires (bathroom lights)
Zone 2 extends from the edges of the bath or shower 0.6 metres horizontally and all equipment must again be IPX4 or 5.
All other areas are deemed to be outside the zones.
Other things to know about wiring your bathroom light:
All circuits in a bathroom need to be protected by an RCD of 30mA. Whilst this is the current regulation it is not obligatory to upgrade the circuit if you are only changing a light fitting. Any new circuit however must comply.
Bonding: You may have seen small green and yellow cables in bathrooms that connect together the pipes etc, this is bonding and prevents differing ptentials appearing across the various parts of the bathroom. Bonding should conect all metallic items together and the cpcs of all electrical circuits. Bonding may be omitted if every circuit is protected by an RCD and their respective cpcs join at the consumer unit.
As you can see, replacing your bathroom light may not be as simple as it first appears. Be safe, employ an electrician.
