How to supply hottub

[Dvyj123]

I have someone that wants a hot tub installing and it’ll be my first time, I have came up with anxixeaxfwanted to check it was correct. I wanted to take swa from the CU to a rotary isolator 2m from the tub, then put a earth stake in near the isolator and connect that to it aswell then go from the isolator to the hot tub in either swa or a flex. Thanks

 

[marcuswareham]

If you were trying to mitigate the effect of a PEN fault on a PME supply then you would not connect the earth rod to the earth from the CU but instead make the hot tub a TT island

 

[Dvyj123]

If you were trying to mitigate the effect of a PEN fault on a PME supply then you would not connect the earth rod to the earth from the CU but instead make the hot tub a TT island

What would I have to do then? Just carry L+N through the whole installation but with the earth when I get to the isolated just connect the earth from supply and the flylead from supply in connector block and then on the load side out a earth stake in to make that side TT?

 

[buzzlightyear]

What would I have to do then? Just carry L+N through the whole installation but with the earth when I get to the isolated just connect the earth from supply and the flylead from supply in connector block and then on the load side out a earth stake in to make that side TT?

Use swa to the rotory switch line& n and earth, but do not wire the earth inside.
TT from the rotory switch.

 

[Dvyj123]

Use swa to the rotory switch line& n and earth, but do not wire the earth inside.
TT from the rotory switch.

Would I just have to take swa from cu to a double pole rotary isolator, gland and fly lead to earth at the cu end and then at the isolator just connect up the live and neutral and leave the earths disconnected, take swa from the isolator to the hottub and then put a stake in under the isolator and connect it to the sheath of the load to hottub with a banjo ? Also would the mcb have to be a C type ?

 

[oscar21]

I put the supply in for my neighbours hot tub a while ago, I just ran a 3 core SWA to a rotary isolator and left it at that, they had a TNC-S supply. I figured it was up to the hot tub company to make the correct earthing arrangements or to ask for a earth rod etc.
I'm not sure what they did to be fair but looking at their hot tub everything about it is plastic, there isn't anything metal you could possibly touch whilst using it anyway. I'm sure a dropped neutral would manifest itself somewhere else before you ever came into contact with something metal on a hot tub.

 

[Dvyj123]

I put the supply in for my neighbours hot tub a while ago, I just ran a 3 core SWA to a rotary isolator and left it at that, they had a TNC-S supply. I figured it was up to the hot tub company to make the correct earthing arrangements or to ask for a earth rod etc.
I'm not sure what they did to be fair but looking at their hot tub everything about it is plastic, there isn't anything metal you could possibly touch whilst using it anyway. I'm sure a dropped neutral would manifest itself somewhere else before you ever came into contact with something metal on a hot tub.

Would there be anything wrong with running the earth straight through as normal to the hottub, then just put a earth stake in and connect to the frame as it is metal, there is also a terminal for it on the hottub but previous owners said they didn’t have one, just thinking incase the neutral was lost in future

 

[oscar21]

Would there be anything wrong with running the earth straight through as normal to the hottub, then just put a earth stake in and connect to the frame as it is metal, there is also a terminal for it on the hottub but previous owners said they didn’t have one, just thinking incase the neutral was lost in future

I suppose its whatever the manufacturers instructions say, if they say TNC-S need an earth road supply only then you would have to do that, do they even stipulate what the earthing arrangements are?
Although maybe not correct I look at things from a pragmatic viewpoint nowadays and all I see every day is horrendous electrical work everywhere I look yet no-one is ever killed or injured or even any property damage for that matter, all customers ever say is well its been working fine for 20 years now.
Lets say you export the earth, for someone to get killed they would have to firstly be working on a metal bit of the hot tub, naked and wet, sat in some wet soil and not some plastic grass, and for the neutral of a local underground cable to be lost without anyone noticing all the lights dimming and the TV switching off first. Chances of all that happening for a perfect storm - zip.

 

[Dvyj123]

I suppose its whatever the manufacturers instructions say, if they say TNC-S need an earth road supply only then you would have to do that, do they even stipulate what the earthing arrangements are?
Although maybe not correct I look at things from a pragmatic viewpoint nowadays and all I see every day is horrendous electrical work everywhere I look yet no-one is ever killed or injured or even any property damage for that matter, all customers ever say is well its been working fine for 20 years now.
Lets say you export the earth, for someone to get killed they would have to firstly be working on a metal bit of the hot tub, naked and wet, sat in some wet soil and not some plastic grass, and for the neutral of a local underground cable to be lost without anyone noticing all the lights dimming and the TV switching off first. Chances of all that happening for a perfect storm - zip.

Yeah I guess not everything is gonna be perfect nowadays. Would it be just easier to just run it pme the whole way through the installation to the hottub and not worry about about a stake. Or to be safe lose the supply earth at the rotary isolator and stake the load side? Not 100% as first time doing hottub

 

[oscar21]

Yeah I guess not everything is gonna be perfect nowadays. Would it be just easier to just run it pme the whole way through the installation to the hottub and not worry about about a stake. Or to be safe lose the supply earth at the rotary isolator and stake the load side? Not 100% as first time doing hottub

There is an expensive problem, problems actually, with earth stakes and hardly any problems with PME and those expensive problems are - drains, electric cables, water pipes and gas pipes. A simple 3 terminal connection that dodgy dave from the pub can do could mean a multi £k bill for you.

 

[Dvyj123]

There is an expensive problem, problems actually, with earth stakes and hardly any problems with PME and those expensive problems are - drains, electric cables, water pipes and gas pipes. A simple 3 terminal connection that dodgy dave from the pub can do could mean a multi £k bill for you.

So would just be safer to go with pme throughout the whole installation?