Hot tub installation !

[Chr!s]

If the hot tub was located on bare ground or grass, i think i'd be also installing a rod, even if it was a TN-S supplied installation. Your still going to get a potential difference between true earth and the DNO TN-S earth.....


As for the Regs, i think they state somewhere, that a TNC-S supply can be used, for supplying hot-tubs and the like provided an earth electrode of a certain value is also provided.... I think that value was around 20 ohms, but i wouldn't swear to it...

Nothing like PME E54, i very much doubt you would feel any sensation on a TN-S.

As for an Electrode on a PME, for it to be any use you would be looking at very low single figures.

A lot of these Hot Tubs are class II as well.

 

[electric will]

Further back in this thread it was mentioned that someone had a small tingle while getting in and out with tncs to that why I've decided to tt. As long as I can get less than 199 ohms.

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Only kidding about the 199. Don't start biting me

 

[SPARTYKUS]

Hot tubs are class II? Excellent.

 

[SPARTYKUS]

If you're getting a tingle somethings very wrong

 

[electric will]

Maybe small earth leakage from the element I'll find the post it wasn't me that said it.

 

[electric will]

I replied in the other thread, I installed my tub using the supplied tncs earthing arrangement also putting a rod in at the tub end. This rod was well below 22 ohms as stated in the regs, the only problem I had was when you got out the tub and one leg was on the floor and one in the water you could feel a shocking feeling, slight difference between true earth and suppliers earth, therefor I disconnected the suppliers earthing and made the tub tt. Alls fine now so that's how I install them from now on!

From page 2 also he said the voltage between the water and earth rod was only 2 v

 

[Chr!s]

Further back in this thread it was mentioned that someone had a small tingle while getting in and out with tncs to that why I've decided to tt. As long as I can get less than 199 ohms.

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Only kidding about the 199. Don't start biting me

On a PME, yes its very possible, its also possible if you TT it to, be careful where you put that rod

If it class II where's the risk?

 

[SPARTYKUS]

Interesting. Thanks Will

 

[electric will]

I may be wrong here but...l even if it is class two would the element still be in contact with the water, anyway the one I'm doing this week is class one, no exposed metal but when you open the cover the pump and heater unit are metal

Back to the post I copied, personally I don't think youd feel the 2 v so the insulation in the heater is breaking down when getting hot. 2 nod thing the rcd should trip at a max of 50 v probably less

 

[electric will]

Ref carefully where the rod goes, my plan is to put it so there is Noway it can be touched while getting in and out, but sort of as close as I can. If you know what I mean

 

[keniff]

If you're getting a tingle somethings very wrong

I believe its because everything is bonded back to an earth bar in the control box, including the pumps casings and frame, elements heating tubes etc, there is a little earth leakage from the heating element and in turn you feel it when you touch suppliers earth (in this case the water is included as its being heated and running through the heating pipes and being pumped) and true earth (in this case the concrete floor ( I had not finished the decking) not enough to hurt but enough to feel it! Iv heard of it before, a boy sat in the tub and his girlfriend who was standing on the bare ground and she gave him a kiss and got the tingles lol!
Anyway mines all fine now it's TT. Even when it was tncs with earth rod I still got the 2v pd so I isolated the suppliers earth at the hot tubs consumer unit

 

[Engineer54]

Nothing like PME E54, i very much doubt you would feel any sensation on a TN-S.

As for an Electrode on a PME, for it to be any use you would be looking at very low single figures.

A lot of these Hot Tubs are class II as well.

I didn't say it was anything like PME. However, there is still a real difference between an electrical supply TN-S earth and true earth. A potential difference will be present. Now if were talking about this hot tub being located on wooden decking, i wouldn't bother with installing a rod at all, but on bare ground or grass, ...always better to air on the safe side.

You could well be right about some of these tubs now being Class 11, but i've personally never come across one to date...., But then most of the units i've worked with or come across, have been American and Canadian jobby's and most of those are supplied with an earth rod as part of the installation kit... Also, most of those hot-tubs have integral RCD's in the control panel...

 

[Guest55]

Also, most of those hot-tubs have integral RCD's in the control panel...

if they are USA / Canadian built then the rcd's arent going work with a UK supply.

Anyways , the hot tub install i mentioned earlier was all wood construction with metal internal control boxes that can only accessed by removing a panel using a tool
i consider this a class 2 piece of equipment , dont know how others may feel ?

 

[OldeSparky]

i wonder how many hot tubs dont have an earth rod??

 

[keniff]

i wonder how many hot tubs dont have an earth rod??

Most I've seen to be fair!

 

[SPARTYKUS]

Just use the PME

 

[Engineer54]

if they are USA / Canadian built then the rcd's arent going work with a UK supply.

Anyways , the hot tub install i mentioned earlier was all wood construction with metal internal control boxes that can only accessed by removing a panel using a tool
i consider this a class 2 piece of equipment , dont know how others may feel ?

All higher powered equipment in the States like cooker ranges, tumble dyers, etc etc, are 220/240 volts.... Hence ALL hot tubs in the States and Canada are 220/240 volts... Never seen a 115 volt hot tub anywhere.

 

[electric will]

115v + hot tub=FAT cable

 

[Engineer54]

115v + hot tub=FAT cable

Exactly!!!...lol!!!

 

[electric will]

Take it in the USA they have 115v 2 phase supply then do they? Or do they gat all 3 phases to the house?