help with wiring my extention

[shamee]

i am putting a self contained flat on the side of my house, it will have a cooker and a shower plus the normal lighting and usage of a flat.I am looking to take the power from my house to a consumer unit in the new build. what cable would i need to run from my house to power the new build please.Can it be done through a single cable? thanx in advance guys

 

[Spark123]

It possibly can be from one cable however it isn't as streight forwards as this
You mention a shower and a cooker, if you already have a few high current rated devices your own supply might not be adequate hence you will need to have a new supply put in for the flat.
What else is on the supply and what size supply is it?

 

[sparkyspike]

Yes, you'll be able to do it in one cable. Probably 3-core steel wire-armoured (SWA). Now you need to concern yourself with the load on the new installation, the earthing of the new installation and who is going to do the work. Once you've worked out the loading and earthing requirements, you can work out how the cable is going to run to the new installation (buried?) and how big the cores need to be.

 

[ericmark]

This is where one has to get out crystal ball. But I'll try to give a few pointers.
1) Total power likely to be supplied to house is 100 amp so maximum will be 25mm cable and using thermosetting cable clipped direct maybe 16mm unless the distance means volt drop needs considering.
2) If it is to be supplied from house consumer unit then a 50 amp MCB is about the largest you can fit so then we drop to 10mm and if again using thermosetting cable may even drop as low as 6mm.

But then you want to run a shower then you could be talking about the total supply to flat will be needed just for shower.

So in reality you will need to get a separate supply for flat.

So next question is how can you reduce usage.

So forget direct heating a shower if you want a shower than used stored water not direct heating.

The same applies to main house.

So looking at minimum then with baby belling cooker and a immersion heater for hot water you could reduce demand to around 32 amp at which you could be using a 32 amp supply which would need around 6mm cable.

So to answer your question you need somewhere between 6mm and 25mm cable.

Yep I know it doesn't help much.

I wonder where on the river Clwyd you live. We normally enter county name like Wrexham, Flintshire or Denbighshire? May be I should change my entry to Alan?

 

[shamee]

well i will be getting someone in to do the work but just wanted to know if its possible to do it off my supply as the flat is just for family use. was going to run cable along the existing building from my main consumer unit as its concrete and not able to bury the cable. my main concern was if a single cable would be sufficient to take power to new build and if so what size breaker would be used in my consumer unit in my house

 

[shamee]

thanks for your help guys really appreciate it

 

[shamee]

By the way its wrexham im from but clwyd was the nearest on the drop down menu cheers anyway

 

[ban-all-sheds]

well i will be getting someone in to do the work

Then let her take care of everything.

but just wanted to know if its possible to do it off my supply as the flat is just for family use.

I think you'll find that a shower consumes the same amount of power whether it's being used by a family member or a complete stranger.

Ditto the cooker, lighting, etc etc etc.

How on earth can you think that one of the factors in the design of an electrical installation is whether the people using it are related to the people next door?

was going to run cable along the existing building from my main consumer unit as its concrete and not able to bury the cable.

Please don't - that's the job of the someone you get in to do the work.

my main concern was if a single cable would be sufficient to take power to new build and if so what size breaker would be used in my consumer unit in my house

Why?

That's why you are paying someone to do the work. It's notifiable, and if you think you can present her with stuff you've done and get it signed off you may find you're expensively mistaken.

What did you tell your council would be the way that you would ensure compliance with Part P when you submitted your Building Regulations approval request?

 

[flameport]

i am putting a self contained flat on the side of my house

Self contained means you should have a separate supply put in.

Connecting this via your own property will cause problems in the future, and you will end up having to put a separate supply in anyway.

 

[securespark]

Is there intended to be any access to the new build from the old?

Does the new build have independent access (ie its own front/back doors)?

Are you registering the new build as an independent address?

 

[ericmark]

By the way its wrexham im from but clwyd was the nearest on the drop down menu cheers anyway

So good they named it twice. But admin still does not know it exists.
You need to look out for all the sons of Glyndwr they may have given up blowing up pipe lines but who knows what they will do next now they have their own University!

Anyway re-reading your post you don't seem to understand how there are many sizes and types of cable. The size is referred to as the cross sectional area which can be confusing as 6mm should be written 6mm² and is not the diameter of the cable.

So to carry extra current we use bigger cable not multi-cables. Although you can't bury the cable it may still need some physical protection either built into the cable with steel wire armour or by extras like conduit or even simply selecting a route where it is unlikely to be damaged.

All best Eric
Edited to insert missing "not"

 

[davelx]

The size is referred to as the cross sectional area which can be confusing as 6mm should be written 6mm² and is the diameter of the cable.

So which is it? The CSA or the diameter?

 

[ericmark]

Sorry my mistake should have read: The size is referred to as the cross sectional area which can be confusing as 6mm should be written 6mm² and is not the diameter of the cable.
Thank you for pointing out error.