Wiring a hot tub

[RyanPaul]

I am wiring a hot tub, I've designed this circuit

What would you do? Looking for advice

I am am going to put 4x4 metal clad/boxes next to the CU's to terminate the earth an running the cores straight through into the CU's

 

[Leesparkykent]

It's not a job for a diyer. The work is notifiable and not as easy as just simply wiring it up as you have other things to consider like earthing and bonding. Get a sparks in.

 

[malcolmsanford]

To be honest I would think the 6mm sub main again. If it is normal 70c SWA and your burying it then realistically your looking at around 46amps. I would be looking at something like 10mm at least and even perhaps recommending a 16mm. I did notice you never designed a socket circuit. pound to a pinch of salt they will want sockets up there once they realise that hot tubs will come with music, fridge for drinks, perhaps a heater etc. By advising 16mm your client will have room to expand the installation without redigging trenches/rerunning SWAs

The water supply to the hot tub ..........where and how is that coming into the area. If it's going to be plastic then you won't have to worry about bonding the service. Is there any metal work around that needs bonding?

I'm assuming you are extending the equipotential zone from the house. Personally for an hot tub in a garden I would look at trying to TT the system

 

[Leesparkykent]

To be honest I would think the 6mm sub main again. If it is normal 70c SWA and your burying it then realistically your looking at around 46amps. I would be looking at something like 10mm at least and even perhaps recommending a 16mm. I did notice you never designed a socket circuit. pound to a pinch of salt they will want sockets up there once they realise that hot tubs will come with music, fridge for drinks, perhaps a heater etc. By advising 16mm your client will have room to expand the installation without redigging trenches/rerunning SWAs

The water supply to the hot tub ..........where and how is that coming into the area. If it's going to be plastic then you won't have to worry about bonding the service. Is there any metal work around that needs bonding?

I'm assuming you are extending the equipotential zone from the house. Personally for an hot tub in a garden I would look at trying to TT the system

I doubt he has a client Malcolm as the OP is a DIY member.

 

[bmines67]

I would also re-visit the idea of having the hot-tub circuits protected by 2 x 30ma R.C.D's. Is there a need to have the distribution S.W.A, R.C.D. protected ?

 

[Welchyboy1]

Also what else is supplied on that rcd side of your main consumer unit, and the installation as a whole?

is 63A max load RCD sufficient?

Also what size is the main fuse?

What else is supplied by the installation, electric shower, cooker, electrical heating/ immersion

 

[Guest77]

I am wiring a hot tub, I've designed this circuit

What would you do? Looking for advice

I am am going to put 4x4 metal clad/boxes next to the CU's to terminate the earth an running the cores straight through into the CU's

How far from the house DB is the shed? lets get that answered then we can start the advice, that said as Malcolm mentioned a 6mm2 will not be adequate, lets have the cable length please.

 

[Paul.M]

Moved to the DIY section.

 

[Darkwood]

Hi RyanPaul - some valid and important questions have been ask here and very relevent to the safety of your proposed install, for the thread to progress can you please address the questions and answer as best you can.

Your Diagram is somewhat vague -

Is the Hot tub going to be protected by 2 no' rcd's in series?
You have shown cable sizes - to confim these are correct can you provide your cable calculations?
What is the nature of the supply to the property, this could have a large bearing on the earthing arrangement you choose for th shed and tub?

Can you address the points put to you in post 3 please.

From previous threads and posts you say you are qualified Part P registered so in respect of this you should have no issue providing the info for the questions put to you and also showing how you arrived at the cable sizes through calculations when asked.. if we are to ensure the info given is safe for your installation we do need to ask these questions.

 

[RyanPaul]

I'm 17th ed, I just got put in the DIY's section because I lacked experience at the time of my last post.

 

[Darkwood]

I'm 17th ed, I just got put in the DIY's section because I lacked experience at the time of my last post.

Can you address the points raised in my post 9 and malcs post 3 - for the correct advice to be given these questions need to be answered to progress the thread and provide the correct advice .. thankyou.

 

[RyanPaul]

The company supplying the tub has required the the supply is RCD protected and that there is a rotary switch local to the tub.
The tub is filled by tap so there aren't any pipe work to worry about, the Earth at the house is TT

 

[RyanPaul]

The CU has RCD 1 up lights, dwn lights, smoke alarm, water heater, kitch sockets.
RCD2 heating, cooker, sockets.

im installing from RCD2 side

 

[RyanPaul]

the main switch is a 100A, on RCD 2 there is only the heating and sockets used on this as cooker is gas, heating is only used in winter.

what I have is sockets on a B32, cooker B32, heating B6, this is all on RCD 2

 

[RyanPaul]

The shed is 6 meters away from the CU