Hot Tub shock

[aaronstuart]

Been to look at a customers hot tub today to assure him it was protected by an RCD which it was.

This installation was done a couple of years ago, with a dedicated 20 amp supply, and ran in armoured.
Its a PME supply.
No earth to water which will be sorted asap.

He has informed me that on 2 occasions he has had a nasty shock while testing the temperature of the water, as he was standing on the ground. ( the tub is outside ).
I couldn't see anything wrong with the circuit wiring visually, but i was unable to test it.

When he phoned up the manufactures, they said it could be a bad earth connection resulting in feedback? Could this be caused by there being no earth on the incoming water pipe?

Any advice would be much appreciated on how to deal wtih this.

Obviously i told him not to use it.

Many thanks

 

[sparks1234]

I had a similar problem a couple of years back, my SWA run was probably 60 mtrs. When we installed it everything was working great and we walked away preparing the invoise.
I had a call the next day saying they were getting shocks when getting in the tub.
The probelm was when cocking a leg over whilst still standing on the grass. It turned out to be a potential difference between earth (as in the mass of) and the earth at the incomer.
We solver the problem by installing a stake as near to the tub as possible and earthing the isolator down there.

 

[aaronstuart]

I'd say the run is no more than 10m.
rcd protection is from the main board.

Would it be best to earth the swa from the main board, then earth rod to earth connection of hot tub?