supply for hot tub and garden services

[alan132]

been asked to install a supply to a hot tub.
old one that is there has been fitted to a board in a shed.
the feed to the shed db is 2.5mm then at the house 6mm.
there is no power there due to tripping.

i want to install a new supply and get rid of all that.

they may be getting rid of the shed and asked for the new board closer to the tub area.
so a ip65 cabinet will be fitted.

my confusing is that the house db has a spare rcd way.
i was thinking of running a swa to a sub board with just a main switch and mcbs and relying on the house rcd to proctect.

reason for the board is they what the sockets and shed to still work.

the earthing is a TN-S setup.

in my head i cant see why its a problem as its still being protected by a rcd.

 

[Octopus]

I always avoid having outside sockets on the same RCD as the house, because sooner or later it will start tripping.

what configuration CU is it?

 

[telectrix]

better to have the RCD at the shed/tub end. is the house CU a hi-integrity board?

 

[alan132]

I always avoid having outside sockets on the same RCD as the house, because sooner or later it will start tripping.

what configuration CU is it?

It's a dual rcd

 

[alan132]

How about is i fit a 63A fused switch at the mains and run off that?
Will I have to up the cable size from 10mm to 16mm?

 

[telectrix]

check in the CU. see if you have 3 N bars. if so, you can do it with a slight shuffle of the MCBs.

 

[telectrix]

what's the hot tub rating?

 

[Octopus]

Will I have to up the cable size from 10mm to 16mm?

What makes you think you would need 16mm - how long is the run? and whats the anticipated load of the hot tub and other devices?

AND watch out for the cost of IP rated cabinets for the garden CU. Decent ones cost and what would you plan to attach it to?

 

[alan132]

Been asked to have a 25a trip fitted so that 32a cos you can't get them.

The sockets will be a radial so 20a if that
And then the shed couple of sockets and 3 lights.

Run to the proposed area roughly 30m

 

[Midwest]

I can see that Part P raising its ugly head again

 

[telectrix]

and what about the fake tanning equipment, being as how it's in essex?

 

[alan132]

Don't know about that

I am tempted just to fit a small board in the house and just run the tub off it

 

[Wilko]

As Tel has said, sooner or later the hot tub ++ will start tripping and some house circuits will be affected. There won't be any discrimination between the house CU RCD and the remote RCD, wherever it is put. So if you have decided the remote hot tub is ok to run on TNS and you can't do the high integrity rearrangement Tel has mentioned, then I'd think about cheap and cheerful just using that spare way perhaps?

 

[alan132]

I am thinking of fitting a 63A fused unit in and running to the new board
There is a Henley block there
Will make the out side separate from the house.

That was my first thought
There is a spare way in the board
Run off that too the new board and rely on the house rcd

 

[polo1]

Interesting thread. Me thinks if a diy'er came on asking similar questions they would be told to get an electrician involved.
IMHO people shouldn't be designing a new circuit via an Internet forum; by all means do the calcs then ask on here if it looks correct ( I appreciate not all sparks have to regularly do instal design so get rusty on the calcs side of things).
Just a thought!

 

[Octopus]

So no firm details of the load .....

Have you asked your scheme what they recommend?

 

[mhar]

Been asked to have a 25a trip fitted so that 32a cos you can't get them.

Eaton do a 25A B type rcbo which I have used and I believe sbs do one as well. If you can get an rcbo I am sure you can get a 25A B type mcb

 

[alan132]

Been told to fit a 32a as it was a american recommendations.