MFI installing electric shower

[theregistry786]

Hello.

I have MFI contracted installers in at the moment doing installing an electric shower (prior it was just a mixer). A stud partition exists to hid the plumbing for the shower

I have a question about the electrics. The electric wire is hanging outside of the stud partition where the internal piping is i.e. visible through top of wall straight to the electric shower. They were planning to cover the wire behind the tiling (the tiling is also going over existing tiling).

Can anyone pls offer advise particularly electrical safety to this type of approach. I have asked the electric wire to be moved behind the stud partition.

Thanks in advance.

M

[JoeJoe]

I cannot see how an exposed electric wire inside a shower cubicle/enclosure can pass any safety reegulations...

[Colin Wilson]

How bloody thick were they planning on putting the tile adhesive ?

I think i'd be asking their employer to come out immediately and tell you how long they've been Part P qualified :-}

[Brian]

You should certainly be asking them to show that they are qualified to self-certify under Part P of the building regs. You will need that certificate if you ever want to sell the house. If they can't provide, then they should have made it clear that you would have to get your council building inspectors to come and inspect it after they finished.

[Brian]

Oh, and I take it that you have an RCD in the system?

[David Hansen]

On Fri, 4 Jan 2008 00:22:56 -0800 (PST) someone who may be [e-mail] wrote this:-

On a strict reading of BS7671 someone might argue that it complies, provided that the entry of the cable into the shower unit is suitable for use in what is presumably Zone 1. Presumably this entry is on the top, what glands are fitted?

I would argue that it does not comply with the good workmanship provisions. Your suggestion of moving it to behind the partition is a sound one, as it makes the cable entry subject to less water.

The tiling should have been done before the shower was fitted. Is the new tiling going to be placed around the unit or is it going to be removed and refitted after tiling?

Perhaps they cut the cable too short and are hoping to bluff their way out of this.

[adder1969]

Go on, tell us how much you're paying :-)

[Tim..]

So with a minimum of a 6mm cable, possibly 10mm (depending on length of run and rating of shower) you'll be happy with them using circa an inch of tile adhesive??

It isn't permissbale to bury the cable anyhow! Part P springs to mind.......

Tim..

[John Rumm]

Where do you get an inch from? Even 10mm^2 T&E is less than 10mm thick across the narrow axis.

It is fine to bury a cable (standard practice in fact) so long as it is in one of the proscribed locations: Horizontally or vertically in line with a visible accessory (i.e. the shower) or within 150mm of the corner of the room or where the ceiling and wall meet.

[John Rumm]

Many electric showers have the cable entry designed such that it is behind the shower, and requires the cable to enter travelling upwards. It then normally folds over and either across or back down again within the enclosure for termination. This makes it impossible for water to run along the cable into the shower. There are not usually any glands at entry - relying on gravity and the covering of the cable entry point to prevent water ingress.

Indeed, loosing it under tiles is a bit of a hack, but if done well could be acceptable. (you would probably need to cut a shallow chase in the old tiles to accommodate the cable though).

Tiling round it would be bad news (and ugly)...

[Bob Eager]

I think you mean 'prescribed' - big difference!

[Si]

In message , John Rumm writes

A typo but rather a fundamental one - presumably you meant prescribed not banned (proscribed).

[adder1969]

I might imagine that is what the intention is. The "electician" has put the shower in and they're waiting for the "tiler" to come and tile over, probably after "chasing" the wall with a hammer :-)

[Stuart B]

Tell them to move it in to the partition wall and bring it through to connect in to the shower ....but....surely you are tiling before putting the actual shower box/riser rail up ?

[Andy Wade]

Under the present 16th edition regulations there's no requirement for RCD protection of an electric shower installed in a TN-S or TN-C-S earthed system, provided that the earth fault loop impedance is low enough to ensure 5s disconnection time, and that supplementary bonding is carried out between the shower's earth and other exposed- and extraneous-conductive-parts. The supplementary bonding is _absolutely_essential_ if no RCD is fitted.

Under the 17th edition, which you have the option of using as soon as it's published later this month, and must use for designs done after 1st June, 30 mA RCD protection becomes a requirement, but supplementary bonding can be omitted provided that both the RCD and the main equipotential bonding are present.

[Stuart B]

Thats certainly not the way I'd have done it . Do the tiling ....put the cable INSIDE the partition wall and bring it through a hole in the tiles ( behind the shower) which would be bored after the shower is installed . Doing it this way allows access to the cable should it ever need to be replacing and to my mind bedding the cable in the old tiles then putting new tiles on top of it is just a bodge even tho' it might be all legal .... .

[sm_jamieson]

If in stud wall, grouping factors or insulation can require a thicker cable. Usually it is tacked to a stud to that it will not be surrounded by insulation inside the stud wall. Are they doing it to get away with a thinner cable ? Simon.

[John Rumm]

yup, blame the speeling chucker! ;-)

[David Hansen]

On Fri, 4 Jan 2008 05:07:21 -0800 (PST) someone who may be sm_jamieson wrote this:-

I doubt if either apply in a stud wall inside a bathroom which is only provided to hide the plumbing.

[devonsteve]

I have had to replace several electric showers over the years and always found the cable inlet positions are never the same, would be nice to alter when the cable is nicely tiled over dont you think ?