Hot tub wiring.

[songwritingmonkey]

Hello. Would be grateful for any advice on the following;

I am upgrading my hot tub, the last one being a 'plug and play' type (1.5kw heater). My new tub has a 4kw heater.

The existing wiring is a 10m run of 2.5mm flat twin and earth, not insulated or buried (hot tub is indoors) from a 16A mcb from the consumer unit on the RCD side, through a rotary isolator and cable goes through wall into the spa room.

My question is, should i upgrade the wiring or will this suffice for my new 4kw tub?.

Thank you.

 

[ColJack]

providing no de-rating factors and a suitable installation method ( ie as you said, not in insulation etc ) then 2.5 will be ok, but you'll need to upgrade the breaker to 20A.. 4KW is just over 16.6A at 240V and about 17.4A at 230V ( depending on what the 4KW is based on )

 

[oharaf]

It will require a 20A MCB, the 2.5mm cable should be fine

 

[songwritingmonkey]

Thank you both for the prompt advice.

 

[ban-all-sheds]

1: //www.diynot.com/wiki/electrics:part-p

2a: http://www.google.co.uk/search?sour...en-GBGB302GB302&q=derbyshire+building+control
or
2b: http://www.competentperson.co.uk

 

[ColJack]

does a hot tub come under part P for notification?

it's not a bath, shower, swimming or padling pool or hot air sauna.. so is it still a "special location"?

changing the breaker would though if that was the angle you were aiming at.

 

[ban-all-sheds]

This is a bit like the topic of a few weeks ago where people were trying to claim that if you don't use a shower as a shower then a shower isn't a shower.

“special location” means a location within the limits of the relevant zones specified for a bath,
a shower, a swimming or paddling pool or a hot air sauna in the Wiring Regulations, sixteenth
edition, published by the Institution of Electrical Engineers and the British Standards
Institution as BS 7671: 2001 and incorporating amendments 1 and 2.

The fact that it isn't used for ablutions does not, IMO, mean that a large container full of warm water which is used in exactly the same way, apart from the Radox & Lifebuoy, doesn't count as a bath.

But as you observe, changing the MCB makes it notifiable anyway...

 

[songwritingmonkey]

Thank you for your concern over zoning and part p.

When I originally converted the room to a spa room I took the angle that it actually became a bathroom once a tub was installed and as such, used all the correct zoning and IP rating for all surounding electrical fittings etc.