NICEIC Certification Scheme NICEIC view on PME for an outside hot tub?

[johnstantine]

Hi everybody I'm new to the forum.

I need some help with a small problem concerning PME.
I'm putting in a supply to a 32A commando socket, located on an outside wall, about 30M from cu to be used for a hot tub, there is a 30mA RCD at the cu and the supply to the house is PME. The suppliers of the tub have said the tub is class 1. I know there's a general conflict of opinion with PME outside but I'm using the job for an assesment for my NICEIC domestic installer and am interested on what there opinion is on how the PME should be dealt with. Do they say to convert to a TT, or leave as PME but install an electrode as well, or simply leave as PME.
Any comments gratefully received.
Thanks

 

[ohmeelectrical]

Hope this helps. TT sounds the best way IMO

http://---------------/Publish/WireRegs/WiringMatters/Documents/Issue14_2/2005_14_spring_wiring_matters_swimming_pools.pdf

The ECA state specifically that all exposed and extraneous conductive parts should be separately earthed with a local spike

Electrical Contractors' Association - FAQ's - Electrical services

 

[sparks1234]

I had a problem with a tub a couple of years ago, the tub was about a 50 mtr run of cable and I installed an isolator etc but the tub was on grass, the client kept getting shocks when climbing in when touching the water, its a bit like the cattle wires you get as your directly down to earth and getting possible 30 volts or so difference between the house earth and the mass of earth.
With a stake in the ground it brings them all together.
On the other hand I also put a supply to a pool pump house and my elecsa inspector said as it was 70 mtrs to isolate the SWA from earth and create its own TT system
Hope that helps

 

[andekoch]

I would put the tub onto a TT and divorce the earthing from the house PME.