Plug & Play hot tub installation

[pc1966]

I'd be very interested to learn how you manage this with almost every TT installation?

Well this one time at band camp I drive the rod through a water main...

 

[loz2754]

Well now I'm convinced this a total windup on the part of @Cosy Sparky

 

[DPG]

Well now I'm convinced this a total windup on the part of @Cosy Sparky

I think you're right. And I fell for it. Doh.

 

[marcuswareham]

I can back it up because I am almost the only person who does things correctly, safely, and then applies all the belts and braces - my customers use me because I work on these principles and almost no-one else does.

They do if you are detached AND you are a proper electrician.

This is a bit strong and it is not that clear cut there are so many factors to take into account, you can't just say every single outbuilding needs to be TT (what if that outbuilding is a granny annexe constructed in exactly the same way as the house ? , if PME is ok for the house why not the granny annexe outbuilding). I have supplied PME earth to a garage and bonded extraneous conductive parts (I would have preferred to TT it myself but it was impossible to get enough separation distance between a TT rod and buried bonded PME metalwork, in effect rendering the whole point of making it TT pointless (and if anything making it slightly less safe by losing the low impedance earth). An opposite scenario is an insulated timber shed with an office inside it which could kept the PME earth but there are some extraneous conductive parts (water pipe, etc) imagine the run is about 150m and the SWA is already in the ground when you arrive, it would be a pain to get a 10mm in the ground to bond that pipe so TT could be a way to go (iv had a similar situation)

Some electricians might have experienced an unbelievably high number of RCDs failing & never a PEN fault so would avoid TT as much as possible, another electrician might not have come across a single failed RCD (unlikely) but experienced a lot of PEN faults so would avoid PME, everyone has there reasons for doing thing one way or another but they are still proper electricians striving to do things safely (for the most part!)

If this was my house and my hot tub, If possible I would probably make it TT and have a delayed 100ma RCD for fault protection and a 30ma RCD for additional protection, so there are 2 RCDs protecting it (if one should fail) and then I have not got the risks associated with PEN faults,
but that's just me, I don't like TN-C-S very much as an earthing arrangement as a few people on here would probably tell you.

 

[Midwest]

Unusual that a person has been a forum member for nearly a year, but has only started contributing in the last week, Cosy Spark?

 

[telectrix]

and it looks like he's gone back to sleep for another year,

 

[stevethesparks]

Sub 1 ohm is exactly what I manage to achieve with almost every TT installation - anyone who can't should not be installing TT installations.

I think you have contradicted yourself there, "almost every TT install"