Bathroom electrical installation

Bathrooms and showers rooms are areas of high risk, because of the very low resistance of the human body when wet or immersed in water.

Precaution to be taken are therefore correspondingly rigorous, and the regulations are more severe than those for most other locations.

The relevant standard is IEC 60364-7-701.

Precautions to observe are based on three aspects:

• The definition of zones, numbered 0,1, 2, 3 in which the placement (or exclusion) of any electrical device is strictly limited or forbidden and, where permitted, the electrical and mechanical protection is prescribed
• The establishment of an equipotential bond between all exposed and extraneous metal parts in the zones concerned
• The strict adherence to the requirements prescribed for each particular zones.

Classification of zones

Sub-clause 701.32 of IEC 60364-7-701 defines the zones 0, 1, 2, 3 as shown in the following diagrams (see Fig. Q12 below to Fig. Q18)

Fig. Q12 – Zones 0, 1, 2 and 3 in proximity to a bath-tub

Fig. Q13 – Zones 0, 1, 2 and 3 in proximity of a shower with basin

Fig. Q14 – Zones 0, 1, 2 and 3 in proximity of a shower without basin

Fig. Q15 – No switch or socket-outlet is permitted within 60 cm of the door opening of a shower cabinet

Fig. Q16 – Individual showers with dressing cubicles

Fig. Q17 – Individual showers with separate individual dressing cubicles

Fig. Q18 – Communal showers and common dressing room

Note: Classes of external influences.

Equipotential bonding

(see Fig. Q19 )

Fig. Q19 – Supplementary equipotential bonding in a bathroom

Requirements prescribed for each zone

The table describes the application of the principles mentioned in the foregoing text and in other similar or related cases