Wiring for A Whirlpool Bath

[Tim Blank]

Hi, I have just purchased a whirlpool bath. The Instructions for the bath state that it needs to be wired accordingly (spelling and gramar reproced from the orginal!)

"Conneecting to the mains:

For the pump power supply, bring and electrical line using a waterlight lead of a 6 x 25mm section protected by a 2 x 16A magnetothermal switch and equipped by a 30mA differental switch. The earth wire muct be absolutely connected to an earth hold. The resistance of the eart hold much not exceed

3ohm, this electrical line must uniquely serve the bathtub"

Now...

I plan to instal the bath by running and RCD protected Fused Spur (Screwfix

14770) from one of the sockets located in my lounge (small flat). I will then have a pull cord located in the bathroom or wall mounted switch in a cupboard next door which will sit between the bath's pump and the FCU. Is there any problems with doing this?

Many Thanks

Tim

[Mark]

You won't be able to connect it as you describe safely.

From the very broken english description of the connection method I'd say it is pretty much like a shower supply. I feel that it requires a separate circuit of supply totally run from your consumer unit. The protection would appear to be a two pole circuit breaker but the cable size eludes me, "6 x

25mm", 25mm cable size does seem rather extreme. Perhaps it's a 6mm cable that is required.

It would also require an earth cable run straight from the main earth terminal found at your consumer unit.

[Owain]

I'd ask the seller for proper instructions, and if they can't supply them then send the unit back. If it doesn't have English instructions I'd be sceptical it was intended for the UK market or compliant with our safety standards.

Owain

[John Rumm]

Does this bath have any electrical heating capability? It sounds like it could be in electric shower territory for power consumption when heating. If it is simply a pump however then it seems unlikely that it needs the best part of 7kW just for that!

Oooo nice ;-)

Guessing at some of the terms: "magnetothermal switch" = MCB "30mA differential switch" = RCD

the 2 x 16A seems odd - perhaps it does mean 32A. That would also tie up with a 6mm^2 CSA cable (assuming the distance is not excessive). No idea where the 25mm comes into it.

The "The resistance of the eart hold much not exceed 3ohm" seems an odd requirement to specify on a circuit which is also RCD protected. (might make more sense on a circuit that relies on EEBADS protection only - but then the 3 ohm figure would be too high to provide fast enough disconnection of the MCB (a quick look at fig 3.4 in Annex 3 of BS7671 suggest Ze would need to be Now...

If we are talking about a high current drain setup then you will need a dedicated circuit. Even a 16A fixed load would be inappropriate to feed from an ordinary ring circuit.

This bit is fine - the ceiling switch would be better since it is in the same room as the bath and hence allows it to be used for isolation (assuming >= 3mm contact separation and it being two pole) without complex lockout requirements (i.e. there is little danger of someone turning back on while someone else is maintaining the bath). It would also probably need to be of the shower isolator type to handle the current requirements if they are large as we suspect.

[Andy Wade]

I agree entirely. If the manufacturer or responsible supplier isn't providing clear instructions they are probably not complying with the Electrical Equipment (Safety) Regulations 1994 (aka the LVD). The matter should be drawn to the attention of the relevant local Trading Standards department.

[Andy Wade]

Agreed.

It might, perhaps, mean a linked 2-pole MCB, with the intention that the equipment is supplied from 2 phases of a 3-phase system (common in some parts of Europe). Or even with the intention of the MCB breaking both phase & neutral of a single-phase feed (in which case just use an ordinary single-pole MCB in the UK).

Or did it mean 6-core 2.5 mm^2? Lord knows why though. Or a 6 mm o/d cable? Is there a rating plate on the damn thing stating voltage, current, power or VA, no. of phases, etc.?

Agreed: ignore and follow BS 7671 / the OSG.

Quite.

I read "electrical line" as referring to the final circuit supplying the appliance (together with its CPC). IOW it's just saying that this bathtub must be fed from a dedicated final circuit, rather than being hooked into the light with a BC adaptor...

[Holly, in France]

I know nothing at all about electrics, but we have a whirlpool bath and ours has to be on a separate circuit just as you describe, so I think you have interpreted that correctly. Ours also has to be able to be switched off from outside the bathroom in the same way that a shower would be.

-- Holly, in France Holiday Home in Dordogne

[Dave Plowman (News)]

This is how my brother's one was installed by a good pro electrician and conformed to the instructions with it.

[Ed Sirett]

I'm wondering weather it need 2 16A supplies. That would be L,N &E twice over hence 6 x 2.5mm^2.

I agree this product ought not to be fitted unless proper instructions can be supplied. I doubt if it is CE marked (does that make it technically illegal to sell / fit / use?).

[John Rumm]

My mum's also - but then again it is on a 3A fuse in the FCU. It would be a very different matter if the bath included electric heating. (my mum's one uses a continous slow feed of hot water to temper the air being pumped in - but I can see the case for using eletric heating for this instead).

[Andy Hall]

It makes it illegal for it to be "offered on the market" in the EU. This means illegal for a manufacturer or reseller if located in the EU to sell it, but not illegal for an individual to import for own use.

If reported to trading standards, and *if* they decided to prosecute (likely only if Something Bad were to happen), then the penalties are a £5000 fine or six months as a guest in a hotel where one should take care not to drop the soap in the bathroom....

[dennis]

If its a *real* spa pool it could have one, two, or three 5HP water pumps, an air compressor, an air heater and a water heater in it. A 3A spur wouldn't even power the air pump.

The one I was looking at needs a 32A feed and an RCD and that only had one pump.

[Peter Parry]

Double pole 16A circuit breaker, not uncommon in continental fits where there is no reliable differentiation between line and neutral.

RCD

Needs its own feed from the Consumer Unit.

If you are in the UK then yes there is - dear Mr Blur can have you fined up to £5,000 and give you a criminal record for daring to install something in an area classified as a special installation or location.

[Dan delaMare-Lyon]

32A - bloody hell - did he say *bath* or olympic swimming pool?? Our one had similarly cryptic instructions, but when worked out and translated, basically it gets wired in like the electric shower that it replaced - in fact - it used the wiring as it was it's own cct back to the CU with it's own MCB etc.

You have to love the wording in some of these docuemnts tho :)

Cheers Dan.