Quick question.

[mort2376]

Has anyone else had issues with one of these plug in hot tub units ?

Customer bought one and I installed an outdoor 13a socket for it. When I arrived the plug on the hot tub was a 16a, but all the instructions and the manufacturers website confirmed that this was a 13a unit.

Rang the manufacturer and they said they all go out with these plugs on but yes 13a is correct.

Long story short. 2 failed outdoor sockets later I'm thinking that it does need a 16a socket.

The customer said when the water is changed and the unit has to heat up the plug and socket does get warm.

The rating plate says the unit is 3kw which should be fine but after 2 failed sockets I'm not convinced.

The outdoor socket is on its own 20a rcbo fed with 2.5mm 6242y so no problems on that side of things.

I know the regulations state any item over 2kw should be on its own circuit, but no mention of how these should be connected.

Has anyone else had similar issues ? The outdoor sockets are the BG ones. Never had a problem with any of the others I've put in.

 

[Andy™]

probably supplied with a 16a plug knowing that a 13a isn't suitable but if you change it or use a 13-16a adapter and the 13a plug melts then its your problem and not theirs

 

[Fleeting]

What voltage is it rated at and what voltage do you have?

 

[SPECIAL LOCATION]

It could be the 'Plug & Socket" element that is the problem..?
Not liking full load through the pin contacts for any significant duration...

I've seen loads of 2.7+kW washing machine / tumble driers with overheated manufactures fitted moulded 13A plugs.. So I would not be at all surprised to find that a hot tub can fry a plug & socket.

As far as I can remember good guidance was to never connect a 3kw immersion heater via a plug and socket.. although all are rated at 13Amps..

Have you considered a 13A weather proof FCU feeding a 16A socket?

e.g.
https://www.screwfix.com/p/british-...itched-fused-spur-flex-outlet-with-neon/27437
&
https://www.screwfix.com/p/abb-16a-2p-e-surface-socket-250v/1858f

or similar to see how that works?

 

[mort2376]

That's my plan. It's just annoying when you know it won't work but you follow the manufacturers guidance and then it bites you !

 

[Fleeting]

The power it is drawing is dependant from the voltage and it maybe exceeding 13A. What voltage is on the rating plate And what voltage do you have?
If it is 3kw at 230v then applying 240v would put it at 13.6A.

 

[mort2376]

True. Again something manufacturers don't take into account as our voltage is 230 here even though I very rarely see it that low.

Around here it's 238 - 249 mostly.

 

[Fleeting]

True. Again something manufacturers don't take into account as our voltage is 230 here even though I very rarely see it that low.

Around here it's 238 - 249 mostly.

Maybe why it had a 16A plug on it to counter these variations.

 

[Fleeting]

If you have the worst case of 249v you are tipping over 14A.

 

[mort2376]

True but manufacturers should take this into account. Its shouldn't be up to us to have to argue with a customer who has the manufacturer backing them up when they say "sure a 13a sockets fine"

I prefer installing the larger fixed units as they need a 32a plug end of. So much easier. Even with the earthing issues you have to cover.

 

[SPECIAL LOCATION]

True. Again something manufacturers don't take into account as our voltage is 230 here even though I very rarely see it that low.

Around here it's 238 - 249 mostly.

I thought all appliances sold for use in the UK should be compatible with 1988 CENLEC harmonised voltage ranges, as per Note 15. Appendix 2?

i.e.
Pre 1995: from 225.6v up to 254.4v (nominal 240v)
1 Jan 1995 onward: from 216.2v up to 253v (nominal 230v)

So unless your site voltage is regularly 250v+ theoretically it should still work satisfactorily?

 

[Andy™]

I thought all appliances sold for use in the UK should be compatible with 1988 CENLEC harmonised voltage ranges, as per Note 15. Appendix 2?

i.e.
Pre 1995: from 225.6v up to 254.4v (nominal 240v)
1 Jan 1995 onward: from 216.2v up to 253v (nominal 230v)

So unless your site voltage is regularly 250v+ theoretically it should still work satisfactorily?

should

but if its been designed for 13a at 230v then it being an almost purely resistive load then at 250v it'll be well over 13a

 

[Fleeting]

It may well work satisfactory but the voltage variation will have an impact on power draw. The manufacturer will have designed this to a voltage tolerance and that is what we need to know.