Dear All,

We have a challenge with our small building which wasn't initially designed as our home...
We have twin vault compost toilets a la Nick Grant and have little room to wall them off from the rest of the bathroom. The main reasons we needed top do so were because:-
1. Electricity distribution box has to go on wall in compost loo area
2. because we're supposed to have an extractor fan in bathroom, this could this cause problems for compost loo which in any case has its own dedicated fan for drawing smells outside the building?

The main prob. however is the D. box. We would like to put it in a cupboard and then build another cupboard around that....could this pass as a cupboard in an (admittedly weeny) room?

Your guidance would be much appreciated,
yours, Chancer Carol

I believe the issue that a regular consumer units shouldn't be in a humid room so a steamy bathroom is out but a regular loo is ok. If you can find a consumer unit approved for humid conditions then I see no reason why it couldn't go in the bathroom.

The UK wiring codes actually go a little further - there is a zonal concept based on distances from the bath or shower - so within a certain distance of that the consuer unit would be disallowed regardless of IP rating.

The zonal concept stops at any partition or cover (so ceilings, walls floor for example define zones)

Putting the distribution board on a cupboard isn't usually a problem.

If you think in terms of wet and naked then would you want to be handling the fuseboards - that should give you an idea of zones etc - so generally a least 600mm from a bath or 1200mm from a shower measured horizontally would be allowable

Regards

Barney

Well initially I guess you need to determine "humid". If it's running with condensation then any "normal" electrical accessory is going to be a problem. If, however, you have reasonable ventilation then there is no real problem.

In terms of cupboards, one would essentially do the job - I mentioned zoning, and essentially a cupboard in the bathroom would define a zone anyway.

You can get good quality all insulated consumer units that if installed correctly will give you a pretty moisture resistant enclosure anyway

So, put the consumer unit in the "airing cupboard" and take a look at your ventilation arrangements and your away. Don't forget that all electrical circuits serving the bathroom will need 30mA Residual Current Protection (including your former WC area as thats now in a bathroom by definition)

Regards

Barney

I'm familiar with bathroom zones and assumed the OP wasn't talking about zone 0,1 or 2! Zone 3 is now uncontrolled but the regs also give priority to following the makers instructions. I'd be surprised if they allow humid locations which is why I believe it to be an issue in a bathroom. Perhaps I'm wrong.

This thread suggests a consumer unit in a bathroom zone 3 is allowed..

http://www.talk.electricianforum.co.uk/question-answer-board/11209-consumer-unit-bathroom.html

I had this at the inception of part p. It's a loophole within the bathroom regs. Basically there is nothing there to say you can't and if the equipment is out of zone, then there's no IP requirement. I was at that time registered with the NIC and they told me it's within regs. They wouldn't do it and I wouldn't do it, but you can't say it's against regs. Not overly happy with their answer I called the IET techline, they also agreed that there's nothing to say it can't be done, but they didn't like it at all.

One thought is that BS7671 requires all circuits in a bathroom to be protected by an RCD. So what about the meter tails into the consumer unit, no RCD on those. Does that count as a circuit?

Posted By: barneythere is no specific prohibition on a Dist Bd in a bathroom subject to environmental conditions and placing outside zone 2.

Barney has summed up the wiring regulations position admirably.

Common sense suggests putting the unit in a cupboard, but there is one potential snag. I guess yours is a well insulated house, but in the unlikely event of your cupboard being situated on a cold, uninsulated outside wall, then you are going to get condensation inside it. Water vapour finds its way to the coldest place and condenses there.

On the ventilation issue: Building Control will generally require a bathroom fan, but you don't have to use it. I'd say try it and see. If the bathroom fan sucks smells out of the composing toilets, stop using it and ventilate the room by opening a window or (if your house is generally dry) leaving the bathroom door open to the rest of the house. Just make sure the fan is independently controlled, and not wired to the lights. Then you can use it or not use it - whatever works.

(Or if the fan built into the composting toilets is powerful enough, then it can serve as your bathroom fan, though this might take a bit of explaining to your BCO. )