electric shock from hot tub!

[chloellie]

hi i have just taken delivery of a new hot tub which is hard wired into a new electric circuit via an isolator/ a seperate fuse box with MCB /and an RCD but when i put my hands in the water with bare feet it gave me an electric shock! it did this every time to anyone without shoes on.. we have obviously turned it off and are waiting for help from the electrician and hot tub company but they are all on holiday

my question in the meantime is why did it not trip any of the MCB or RCD? the tub remianed on until we turned it off even tho we were being shocked ! does anyone have a clue? do you think it is the new wiring or a component in the hot tub?

 

[flameport]

Most likely is a fault with the tub or the wiring, and the RCD is broken as well.
Possibly the RCD and other parts of the circuit are wired wrongly in such a way that although the RCD is not broken, it does not work as intended.

If you press the test button on the RCD, does it switch off?

What certificates and other documents did you receive when the new circuit was installed?

 

[rebuke]

In theory if you're getting a small shock then that should cause the RCD to trip. It's possible the current wasn't enough to do it (would need to be at least 20-30mA) if it was only a small tingle you were feeling. Alternatively it could have been wired up wrong, or be a defective RCD - when it was installed you should have been given a certificate showing the test results, including trip times for the RCD?

Another possibility is do you have electric under floor heating by any chance - it could be the fault is actually there, and it's just that when you put your hands in the water you've got a path to earth through the plumbing, and are then exposing a fault in the under floor heating. This is unlikely, but possible...

 

[chloellie]

thanks... we have done a test on the RCD by pressing test button when the tub is power on and it tripped immediately!
the shock was more than a tingle but never having been shocked before can't say how severe it was and not really willing to try again

Someone said it can be an earthing issue but the tub is hard wired correctly and the earth is correct we have checked that it is all dry and the cable from the main switch board to the tub outside is 16mm aroumed and only recently been laid so I can't imagine there is any damage to that

 

[Taylortwocities]

Flameports question is important:

What certificates and other documents did you receive when the new circuit was installed?