Bathroom Electrical Zones ...

Aug 17, 2009 11 Replies

Hi



I have a wall in my bathroom, on which I would like to place an illuminated mirror. The nearest source of water is a bog pan on the adjacent 90 degree wall, probably around 1.5m away, as the crow flies. The basin is to the left of that, so farther away, and the bath even further, being against the opposite wall. I have seen a mirror I like, which says that it's approved for use in zone 3. Does it sound like my proposed location *is* zone 3. I looked at the diagram at



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that appears to show a lit mirror above a basin, half in zone 2 and half in zone 3. The notes with this diagram don't seem to make an awful lot of sense. Is there a simple formula for what is considered safe in which locations ?



Arfa


Your proposed location is "outside the zones". (note Zone 3 does not exist any more - it vanished in the 17th edition of BS7671)

So your mirror is fine in that location.

Yup, as described here:

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Thanks for that John. I knew one of you lads would be able to put me straight in short order ... !

Arfa

page. We just have a bare 100w bulb in a bayonet socket as fitted originally. You can stand in/on the bath to change the bulb. Any new rules broken here?

Good point - I will add a section on lighting.

It sounds as if you lamp is in Zone 1 or 2 then (depending on the height of the ceiling). So the light fitting must be IPX4 or better (a bayonet fitting is not). If the fitting is in zone 1, then it ought to be SELV as well.

Not new ones, just some fairly old ones ;-)

On Mon, 17 Aug 2009 15:45:46 GMT someone who may be Geo wrote this:-

To add to what has been said, assuming that lampholder is within

2.5m of the bath then provided it is fitted with a so-called Home Office skirt then no old rules were broken. It could also have been totally enclosed.

From one site I get:- "Zone 1: the area around the bathtub or shower basin up to a height of 2.25m above the floor ..."

and from another:- "Zone 1: The area directly above zone 0 limited vertically to 2.25m above the bottom of the bath or shower. "

and a third says zone two exists above zone 1:-

"Zone 1 is the area above Zone 0, up to a height of 2.25 m above the floor. Zone

2 is the area above Zone 1 up to a height of 3 m"

Getting confused now about the location (21cm horizontally from the bath edge) and 2380mm from the floor (not bottom of bath).

Thanks - yes it does have the HO skirt.

From the horses mouth: BS7671 16th edition: (not got the 17th in an easy to cut'n'paste form)

"Zone 0 is the interior of the bath tub or shower basin. In a location containing a shower without a basin, zone 0 is limited by the floor and by the plane 0.05 m above the floor. In this case:

(i) where the shower head is demountable and able to be moved around in use, zone 0 is limited by the vertical plane(s) at a radius of 1.2 m horizontally from the water outlet at the wall, or (ii) where the shower head is not demountable, zone 0 is limited by the vertical plane(s) at a radius of 0.60 m from the shower head.

Zone 1 is limited by: (i) the upper plane of zone 0 and the horizontal plane 2.25 m above the floor, and (ii) (a) by the vertical plane(s) circumscribing the bath tub or shower basin and includes the space below the bath tub or shower basin where that space is accessible without the use of a tool, or (b) for a shower without a basin and with a demountable shower head able to be moved around in use, the vertical plane(s) at a radius of 1.2 m from the water outlet at the wall, or (c) for a shower without a basin and with a shower head which is not demountable, the vertical plane(s) at a radius 0.60 m from the shower head.

Zone 2 is limited by: (i) the vertical plane(s) external to zone 1 and parallel vertical plane(s) 0.60 m external to zone 1, and (ii) the floor and the horizontal plane 2.25 m above the floor."

The 17th edition regulations say:

701.32.2 Description of zone 0

Zone 0 is the interior of the bath tub or shower basin (see Figures

701.1 and 701.2).

For showers without a basin, the height of zone 0 is 0.10 m and its surface extent has the same horizontal extent as zone 1 (see Figure

701.2).

701.32.3 Description of zone 1

Zone 1 is limited by:

i) the finished floor level and the horizontal plane corresponding to the highest fixed shower head or water outlet or the horizontal plane lying 2.25 m above the finished floor level, whichever is higher

ii) the vertical surface:

a) circumscribing the bath tub or shower basin (see Figure 701.1) b) at a distance of 1.20 m from the centre point of the fixed water outlet on the wall or ceiling for showers without a basin (see Figure

701.1(e) and (f)).

Zone 1 does not include zone 0.

The space under the bath tub or shower basin is considered to be zone

  1. However, if the space under the bath tub or shower basin is only accessible with a tool, it is considered to be outside the zones.

701.32.4 Description of zone 2

Zone 2 is limited by:

(i) the finished floor level and the horizontal plane corresponding to the highest fixed shower head or water outlet or the horizontal plane lying 2.25 m above the finished floor level, whichever is higher

(ii) the vertical surface at the boundary of zone 1 and the parallel vertical surface at a distance of 0.60 m from the zone 1 border (see Figure 701.1).

For showers without a basin, there is no zone 2 but an increased zone

1 is provided by the horizontal dimension of 1.20 m mentioned in Regulation 701.32.3(ii)b)(see Figure 701.1(e) and (f).

John

No probs old boy. Go right ahead. All interesting stuff, and all potentially relevant to the complete bathroom refit I'm currently doing.

Arfa

The wiki on this currently seems to say that all lighting in zones

0,1,2 must be selv. Surely not?

NT

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