Wall-mounted light switches in locations containing a bath or shower

Instances are found during periodic inspection reporting where wall-mounted light switches have been installed in either zone 1 or zone 2 of a location containing a bath or shower. Inspectors are sometimes unsure whether this is permitted.

Solution

Switchgear and accessories must not be installed in zone 0 of a location containing a bath or shower. Also, exept for switches of SELV circuits, wall-mounted light switches must not be installed in zones 1 or 2 (Regulation 701.512.3 refers).

However, wall-mounted light switches to BS EN 603669 (or an earlier applicable standard) my be installed outside or zones 0,1 or 2, provided the design of the switch is appropriate to the situation and takes account of the conditions likely to be encountered (Regulation 512.2.1 refers). Like any other electrical equipment, a wall-mounted switch exposed to water jets, such as for cleaning purposes, should have a degree of protection of at least IPX5 (Regulation 701.512.2 refers). As shown in the following examples, several outcomes are possible where a periodic inspection reveals that a wall-mounted light switch (non-SELV) is installed in a location containing a bath or shower.

• A switch installed in zone 1 or 2 is not permitted and should generally be attributed a Recommendation Code 2 Requires Improvement. This applies even if the switch has a degree of protection of IPX4 or higher
• A switch installed outside zones 0,1 or 2 and where water ingress to the switch is likely, should generally be attributed a Recommendation Code 2
• A switch installed outside zones 0,1 or 2 where water ingress to the switch is not likely (such as a switch having a degree of protection of at least IPX3), does not warrant any Recommendation Code

Regulation 512.2.1

Equipment shall be of a design appropriate to the situation in which it is to be used or its mode of installation shall take account of the conditions likely to be encountered.

Regulation 701.512.2 (part of)

Installed electrical shall have at least the following degrees of protection:
(i) In zone 0: IPX7
(ii) In zones 1 and 2: IPX4

Electrical equipment exposed to water jets, e.g. for cleaning purposes, shall have a degree of protection of at least IPX5.

Regulation 701.512.3 (part of)

The following requirements do not apply to switches and controls which are incorporated in fixed current-using equipment suitable for us in that zone or to insulating pull cords of cord operated switches.

In zone 0:
Switchgear or accessories shall not be installed.

In zone 1:
only switches of SELV circuits supplied at nominal voltage not exceeding 12 V a.c. rms or 30 V ripple-free d.c. shall be installed, the safety source being installed outside zones 0, 1 and 2.

In zone 2:
switchgear, accessories incorporating switches or socket-outlets shall not be installed with the exception of:
(i) switches and socket-outlets of SELV circuits, the safety source being installed outside 0, 1 and 2, and
(ii) shaver supply units complying with BS EN 61558-2-5.

This article is extracted from Snags and Solutions Part 3 published by the: NICEIC Group