New Garage install

[Paul Bunce]

Good morning!
First of all I just want to say I’m not an electrician but I am an electrical (aeronautical) engineer so I’m confident with electrical work but I know I’m not qualified.

I’m moving to a new build house shortly with a garage, the developer will be fitting a 32A supply and a 3 way consumer unit. From that there will be a single double socket (from 16A mcb) and a light (from a 6A mcb).

I wish to upgrade the garage to the following ( please see attached image).

My plan is to fit the socket and lights where I would like them and then get a local electrician to wire it all and certify it all.

Just to clarify my vacuum cleaner, air compressor and a water pump are all tucked away so would like to use a grid switch system to operate them. Oh and apologies for my mistake in the picture, I should have put 6A on the lighting mcb.

 

[ericmark]

First question is cable size to garage, 4 mm would likely be OK for 32A but under size for 40A, and even with 6 mm you have a max length of around 25 meters to keep within volt drop range with 40A but 30 meters with a 32A supply, so one does need to work it out. And that is not allowing for volt drop inside the garage.

However the layout seems OK, but you need to select an electrician before you start, he has to sign for design, installation, and inspection and testing, he can't sign for design if he has not done it, I had same problem, I had the skill and tools to DIY but the council charges are rather high, and I wanted the paperwork as likely to rent or sell. Also all my meters were out of date for calibration, so simply not worth DIY.

I know the reason why non scheme members can't install new circuits or consumer unit unless through council, and I know the council don't seem to have records assessable so unless there was a death it is unlikely anyone will check the work is registered, so in real terms DIY is unlikely to cause a problem, however not to tell you the correct method would be wrong, if you want to break the law that's up to you, but normal reason for getting paperwork is so house can be rented or sold, I assume your not intending to sell, and if an error causes a death the paperwork will not help, they will still find out who really did the work.

I have been shocked to find 2.5 mm feeds to garages, even with a 32A MCB, you need to check.

 

[AndyPRK]

Yes I just hope the builder installs a proper supply (unlikely) and you don’t have to start from scratch.

 

[Paul Bunce]

The 32A supply will already be installed by the builder and they have said it will be supplied from a 40A mcb on the house consumer unit. This will have already been signed off before I take ownership.

I don’t have the paperwork to hand, but I paid to have the supply upgraded from 16a (as my compressor occasionally trips my current mcb in my current, soon to old house). For that I’m certain it said the swa cable was upgraded to 6mm. With a dedicated consumer unit in the garage. Additional £150 over what they supply as satandard

 

[ericmark]

There should be no problem then, may want a C type MCB in compressor supply.

 

[Simon35]

View attachment 164277 Good morning!
First of all I just want to say I’m not an electrician but I am an electrical (aeronautical) engineer so I’m confident with electrical work but I know I’m not qualified.

I’m moving to a new build house shortly with a garage, the developer will be fitting a 32A supply and a 3 way consumer unit. From that there will be a single double socket (from 16A mcb) and a light (from a 6A mcb).

I wish to upgrade the garage to the following ( please see attached image).

My plan is to fit the socket and lights where I would like them and then get a local electrician to wire it all and certify it all.

Just to clarify my vacuum cleaner, air compressor and a water pump are all tucked away so would like to use a grid switch system to operate them. Oh and apologies for my mistake in the picture, I should have put 6A on the lighting mcb.

Why not just mark on the wall where you want sockets, same on the ceiling for lights, and get an electrician to supply and fix the lot? I don't see the gain from fitting a few sockets yourself, it's an hour's work.

 

[AndyPRK]

If you wish to implement that diagram at the cost of an hours labour, then I have some other jobs for you

 

[Simon35]

If you wish to implement that diagram at the cost of an hours labour, then I have some other jobs for you

OK, maybe more than an hour, but it's 8 back boxes probably surface mounted to a garage wall and four fluorescent fittings, not a huge job.

 

[Paul Bunce]

I know it’s fairly vague but what sort of price am I looking at? Garage would be more or less empty.

 

[Taylortwocities]

A day's work plus materials. Including certification and notification.
Cost of a day's work depends on where you live. Chelsea = £1000. Elsewhere less.

PS I would have a separate RCD for the garage and power the garge from a non-RCD way in the house CU.

 

[Paul Bunce]

Wow £1000 for 7 sockets and 4 lights. That seems a lot.

 

[donrkebab]

Wow £1000 for 7 sockets and 4 lights. That seems a lot.

hahaha - Then move out of Chelsea

 

[Paul Bunce]

I’m in Lincolnshire

 

[Taylortwocities]

Wow £1000 for 7 sockets and 4 lights. That seems a lot.

https://www.pimlicoplumbers.com/rates

£90/hour plus VAT

But Lincolnshire, do you have electricity there now?

 

[donrkebab]

Every tradesman in the UK should send Charlie Mullins a Christmas card thanking him for advertising his charges. It means they can all undercut him and tell customers "Well I'm cheaper than Pimlico Plumbers, just look on their website" and earn a small fortune.