Hi I am new to this forum, seeking advice before hiring an electrician.

[grahamc]

Hi, I am not an electrician and need some professional advice before hiring one to undertake and certify the work. I think I have gathered all the information, all be it long winded, sorry in advance.

We are having a home office installed in our garden that comes with all the electrics pre install, 3 double sockets, LED lighting all connected to a MCB consumer unit. We will be running a 4kw portable air con/heater, two computers and a printer in the office.

The house is 16 years and the consumer unit is a MCB type 6 MCBs with the kitchen and detached garage protected by a RCD. The problem we have is, that the consumer unit is full and also on the wrong side of the house. It would mean having a new consumer unit fitted which is ok, but a huge cost digging up all the drive and slabs to lay a cable to the office, because it cannot be elevated.

Now the question! Our detached garage is powered from the final circuit ie the kitchen one with a 10mm buried armoured cable to a MCB consumer unit in the garage. Is it ok to run a buried armoured cable from the garage consumer unit to the new office consumer unit?

Sorry it is so long winded as I am trying to add as much information as I can. Looking forward to your suggestions.

 

[Spoon]

Maybe its just me but I don't quite understand your current set-up.
Are you saying that you have 2 consumer units un your house. One 6 way, with MCB's and another that has an RCD that has 2 MCB's that wire to your kitchen & detached garage? You say that "Our detached garage is powered from the final circuit ie the kitchen one" What do you mean by this? Is the detached garage wired to the kitchen ring?
What is the earthing arrangement of the system?
Can you take some picks and post them of the set-up.

 

[grahamc]

Hi, I only have one consumer unit which has 6 mcb's and a RCD. The garage and kitchen are on the same circuit. As far as I understand it, the garage is on a radial circuit feed from the kitchen circuit to a garage consumer unit. As for the earth! Sorry I have no idea, as I am not into electrics. Reading about radial circuits, I understand that if there is a short in the garage circuit/s it trips the RDC in the house consumer unit. Hope this is clearer

 

[Spoon]

So you are saying that the 10mm cable wires back to the kitchen circuit?
How far away is your detached garage from the consumer unit & kitchen.
How about getting the electrician to add an extra consumer unit next to the original one and then you can wire your home office?

 

[grahamc]

House and garage units

 

[grahamc]

I have no problem with a new consumer unit.. The problem is, running a SWA underground from the new unit to the office as it would mean having to dig a trench in a concrete driveway and lift 40 odd concreted down paving slabs. Where as the 10m 10mm SWA feed to the garage box from the kitchen would be the easiest and most cost effect way. Ie feeding a SWA cable 12m underground from the garage unit to the office unit if this was possible?

 

[telectrix]

it possible to dis. the feed to the garage from the kitchen and re-feed it from the house CU area? re-use the existing buried cable if it's safe to re-use? TBH< i'd need to see the job before giving more concrete advice.

 

[grahamc]

No. It was all built in when the house was built. Cable from the kitchen to the garage is within the cavity and was probably laid through the foundations. The house CU is on the opposite side of the house to the garage, so no joy there except a huge expense digging a trench through concrete.

 

[telectrix]

i have to ask... who was the numpty who decided to feed the garage from the kitchen RFC on a new build, when itr could have easily been done correctly.

 

[grahamc]

I don't know, we have had the house from new 16 years ago. Everything was passed OK by the building inspectors. The electrics have been tested and certified when a new electric shower was fitted 5 years ago.

 

[aesmith]

You'd be better getting one or more electricians to have a look first hand and see if they can find a solution. For what it's worth our supply to the outbuildings is right at the other end of our house from the consumer unit, and our electrician was able to route the SWA via the roof space so that it exited the house at a suitable point for a trench to the building.

 

[telectrix]

whereabouts in shropshire? not too far for me to have a gander if you're towards the north of the county.

 

[Octopus]

Without wishing to sound unhelpful, the only way to determine the best way to do this would be some investigation - especially how the swa is connected to the kitchen circuit!

 

[grahamc]

Thank you everyone for your help. The SWA from the kitchen to the garage has been done correctly through a isolation switch in the kitchen (I called the builder) next door has the same setup as ours and had their garage plugs wired up by a electric, they are running a freezer and washing machine in the garage.

I think the way forward is for me to get a couple of surveys done.. Thanks for your help

 

[GMES]

Thank you everyone for your help. The SWA from the kitchen to the garage has been done correctly through a isolation switch in the kitchen (I called the builder) next door has the same setup as ours and had their garage plugs wired up by a electric, they are running a freezer and washing machine in the garage.

I think the way forward is for me to get a couple of surveys done.. Thanks for your help

Graham it's sockets not plugs Arghh :banghead:
Joking aside if I were you, I would take Telectrix up on his offer, He will give you a fair and genuine assessment of the installation,and what to do to get you were you need to be.