Workshop electrical wiring questions.

[JustBen]

I've just moved into a new rented property and want to sort the garage(workshop) power out.

The workshop is attached to the house but on the opposite side of the house to the consumer unit.

I have investigated the power/lighting and the lights are connected to the downstairs lights.
The sockets are spurred from the upstairs sockets.

I would like to have the workshop sockets running off my rcbo in the spare slot but I'm not sure how to route it through the house as it's rented.

It appears that the socket that is in there is a spur from upstairs.

I want to add 5 double sockets and also keep the original socket too.

So, how would you recommend I do it?

Other than the chest freezer and occasional tumble dryer use, I would only have a max of 2 machines running at once.
The biggest combination would be 1350watt thicknesser and 750watt extractor so 2100watts + chest freezer + tumble dryer if on.

So other than running new cables somehow from the CU, what options would you suggest?

Fit a mini CU on the spur coming from the house?
Fit a fused box on the spur coming from the house?

I hope I've made it clear.

Thanks

 

[MMUK]

No to a mini CU and No to a fused box. As the existing circuit is a spur (ie; only one 2.5mm cable) you are limited to current capacity. I certainly wouldn't want to use it at all for the purpose you intend to - you don't know what else is in the circuit. I would have thought however, that it would be fine to use the existing socket for a fridge/freezer as current draw will be minimal.

In this instance I would be tempted to run a new 6mm T&E main around the outside of the house in a conduit. This involves minimal disruption (two larger holes in walls plus an amount of 6mm holes for saddle fixing) and has the advantage that you can remove it again when you leave, putting everything back as it was. I would connect this to a 63A MCB in your main consumer unit and fit a small consumer unit in the garage with a 63A MCB with a 32A RCD (put your double sockets on a ring main) and a 16A RCD (spare in case you want to fit a 16A industrial socket at a later date). I would leave the lighting as it is.

 

[RogerS]

And then get an electrician to sign it off ? Or is this allowable work under Part P?

 

[MMUK]

Sorry, yes. I'm a qualified electrician so I don't tend to think about that bit, it's automatic lol.

Although, as it's a rented property that the OP has just moved in to, an electrical inspection should be carried out before or as soon after the date a new tenant moves in (otherwise at maximum ten year intervals - stupid time gap IMO, it should be every 12 months). If this hasn't been done yet and he can get the work done before the inspection, it can be signed off at the same time.

 

[MARK.B.]

Best to ask the landlord if you havent already. if its ok to do this,if it is get them to arrange it and pay them for the work.

 

[JustBen]

Thanks for the info.

6mm seems quite a lot.
I've got a reel of 4mm(IIRC) 3 core armoured cable that I could use.
I've already got a mini CU with 16 +6A mcbs and DP switch plus a 32A rcbo which could go in the main CU.

Telling or getting the landlord to do it would cost a fortune and/or cause complications which is rather avoid.

 

[JustBen]

My plan was to do everything except the connection to the main CU and get an electrician to inspect my work and make the connection.
That way its a minimal cost and still remains safe.

 

[MARK.B.]

Thanks for the info.

6mm seems quite a lot.
I've got a reel of 4mm(IIRC) 3 core armoured cable that I could use.
I've already got a mini CU with 16 +6A mcbs and DP switch plus a 32A rcbo which could go in the main CU.

Telling or getting the landlord to do it would cost a fortune and/or cause complications which is rather avoid.

I understand when you say it might cause you complications but when your landlord finds out as he will have to have the original copy of the compliance paperwork (His insurance and yours may well be null and void without it ) then i would imagine that he would be more than a little bit p issed off at you for not having the courtesy to ask his permission to do the work on what is after all his property and not yours.