Installing new mini consumer unit in loft

[adamm]

i am intending to install a new mini consumer unit in my loft as i am making it a habitable place! (Office with a number of pc's, security equipment etc, higher useage than a normal home office!)
It will be feeding sockets around 7 doubles and 4 lights.

I have a single 6mm redundant t/e coming to outside the bathroom that i have easy access to, so my first question is am i ok to use this to feed the new mini consumer unit?
secondly, i will need to extend this cable to the loft, is the best way to do this via a junction box? is so, can you tell me which one i require?

can you tell me what the cable should be protected at the main consumer unit? and lastly, the new mini consumer will serve the new sockets in a radial configuration, is this ok? can you also tell me what protection the sockets and the lights will require?

many thanks in advance

 

[Taylortwocities]

It depends on your propsed load. a 6mm cable is usually fused at 32A (it depends on the routing)

You will need to get Building regs for your conversion as the loft will be a habitable space. The regs application will include the electrical installation.

All the new circuits will require RCD protection and you will need to comply with the relavent wiring regulations.

You will need to have this all signed off to get a completion of the building regs for your conversion. With respect, if you dont know what way to extend your existing circuit you should think about getting a registered electrician to help you out.

Suggest you Google "converting my loft regulations" before you take a step further.

All loft conversions require approval under the Building Regulations. Loft Conversions are not as easy to construct as may be suggested.

They can be very complex and the design needs to consider:

Structural stability
Fire resistance/protection
Means of escape
Smoke detection
A protected stairway enclosure
A fixed stairway to the new floor
Thermal insulation
Sound insulation
Ventilation
Weather resistance
Detailed plans are required for this work to ensure the loft can be constructed.

 

[bongos]

Lots of questions here!

Bearing in mind that if you are turning your loft into a habitable space you will probably need buildings regulation approval. Also bearing in mind that installing a new CU will require notification to your LABC, it might end up easier (and cheaper) getting a spark to do the electrical work who can self notify.

More info here on diy electrical work in dwellings.

Also, while the 6mm feed may be adequate, alot more information is required as to its existing cable route (does it go through insulation etc). There is also the possibility of high integrity earthing to consider if you are going to be running alot of computer equipment on one circuit, due to the increased earth leakage created by the equipment.

With the maximum of respect, your questions suggests that you are at a basic diy level. i would strongly suggest reading up more and learning about circuit design, installation, testing etc before undertaking this project and still think it may be more prudent if you get a spark to do it who will be experienced in installing what you require.

Thats not to say people on here won't help to offer advice but I think you probably need to learn alot more about what you need to do before jumping straight in.

 

[adamm]

thanks guys for the answers, i have considered the 'other' aspects of the conversion, and I have a builder who is undertaking these, my original questions in respect of the electrics, was to double check what the builder was proposing, (not that i don't trust him) but he is going to get the final installation certified, as he needs to for the building regs certification. i wanted a second opinion in respect of what he is proposing. many thanks

 

[ban-all-sheds]

So you have a builder who employs, or subs to, a qualified electrician who is registered to self-certify compliance with the building regulations, and he's given you a spec for the electrical work which goes down to the level of detail of how, and with what, he will extend cables, but you don't trust him, and even though you know nothing about any of it you think that after a couple of posts on an internet forum you'll be in a position to hold a credible argument with him?

I don't think so.

 

[Taylortwocities]

but he is going to get the final installation certified,

He can't do that. The registered electrician who is doing the works will do the certification and do the necessary stuff to enable the Building Regs sign-off at the end.

 

[adamm]

thanks for your help guys, i think i will leave it to the experts, all i was trying to avoid was purchasing the bits for the builder which ultimatley may have been rejected by the electrician when he comes to inspect. the problem is my builder is only employed on labour basis, he's already told me, if the elctrician does not like anything already installed, i would have to pay to rectify (any new materials etc) not labour (this is what i was trying to avoid)....and yes the electrician will certify not the builder, very useful forum, will be coming here again! NOT!

 

[Johnmelad502]

thanks for your help guys, i think i will leave it to the experts, all i was trying to avoid was purchasing the bits for the builder which ultimatley may have been rejected by the electrician when he comes to inspect. the problem is my builder is only employed on labour basis, he's already told me, if the elctrician does not like anything already installed, i would have to pay to rectify (any new materials etc) not labour (this is what i was trying to avoid)....and yes the electrician will certify not the builder, very useful forum, will be coming here again! NOT!

Another one driven away by Batman and his little sidkick.

 

[flameport]

all i was trying to avoid was purchasing the bits for the builder which ultimatley may have been rejected by the electrician when he comes to inspect.

what?

You don't employ a builder on labour only to install electrical systems, no more than you would get an electrician to do building work.

If you employ people on a 'labour only' basis, this means YOU will be responsible for managing the entire project, and therefore you must have the relevant experience and knowledge to not only know what materials are required, but also where to buy them, what quantities are needed, when they should be delivered to the site and what order the numerous trades will complete their part of the work. You will also need to arrange for the relevant applications for building control and planning permission, ensure that skips etc. are provided for removal of waste, scaffolding is provided, and so on.

If you can't do this yourself, then the only option is to pay someone to do this for you.

 

[ban-all-sheds]

my original questions in respect of the electrics, was to double check what the builder was proposing

if the elctrician does not like anything already installed, i would have to pay to rectify

Am I the only one who can't work out whether this work is being done by the builder or by an electrician?

 

[ccam108]

my original questions in respect of the electrics, was to double check what the builder was proposing

if the elctrician does not like anything already installed, i would have to pay to rectify

Am I the only one who can't work out whether this work is being done by the builder or by an electrician?

Sounds like adamm is buying the materials, the builder is installing it and then an "electrician" is signing it off.

As has been mentioned, electricians cannot sign off work that is not their own, so you will run into trouble if there are any problems.

Colin C

 

[ban-all-sheds]

Sounds like adamm is buying the materials, the builder is installing it

 

[ccam108]

Couldn't have put it better myself

Colin C