Connecting Outbuilding to House

G

griffbabe

Hey All,

Can you help me with this?

I have a portacabin with a full compliment of electrics and RCD board.
I want to connect to the house mains.

Generally cabin will run 1200watt heater, 25 watts of LED lights and a modest collection of musical equipment centered around a computer, really nothing heavy.

There is a cable installed already underground that I would like to use, this was put in by previous tenents but is unterminated at either end.
Its a 2.5mm armoured cable which seems heavy enough.

Have looked to hire electricians but very expensive and they are reluctant to make use of original cable even though its already been signed off.

Presently I run the cabins RCD from a typical extension cable and it seems fine so far.

So some questions...

1) Why cant I just stick a plug on the armoured cable and replace the extension cable with it. Whats the dangers here?

2) Is there not a plug in option I could use to terminate the armoured cable and protect the circuit without spurring or having to rip open a wall?

3) Can I run the kind of wattage Im drawing off a standard 13amp plug?

If anyones got any great simple workarounds or know of products designed to make this easy please let me know!

Thanks!
 
Sponsored Links
Joined
22 Feb 2009
Messages
1,582
Reaction score
149
Location
London
Country
United Kingdom
Oh dear!

I expect the electricians won't touch it because the cable is too small.

How far is the run?

You cant put a plug on an armoured cable.
 
G

griffbabe

Why cant I put a plug on an armoured cable?
And why is it too small, should be good for 25amps right?
I am essentially doing this already with the extension cable.
 
Joined
30 Jun 2009
Messages
21,627
Reaction score
2,567
Location
Londonderry
Country
United Kingdom
Can you help me with this?
will try!

So some questions...

1) Why cant I just stick a plug on the armoured cable and replace the extension cable with it. Whats the dangers here?
Have you tried terminating SWA in to a plug correctly?
2) Is there not a plug in option I could use to terminate the armoured cable and protect the circuit without spurring or having to rip open a wall?
There are always options, but often they are either not compliant or will require some extra work.
3) Can I run the kind of wattage Im drawing off a standard 13amp plug?
2990 watts would be the maximum for a 13A plug.
But what distance is the cabin from the source of supply.
If anyones got any great simple workarounds or know of products designed to make this easy please let me know!
easy way would be to employ someone that knows what they are doing, can inspect, test and sign off.

You say this installation has already been signed off, how does that work then?
 
Sponsored Links
Joined
31 Mar 2006
Messages
20,002
Reaction score
1,380
Location
Leeds
Country
United Kingdom
Why cant I put a plug on an armoured cable?

Because you can't.

It physically will not fit, and there is no facility to earth the armouring with a plug.

And why is it too small, should be good for 25amps right?


No. Have you taken into account permitted volts drop and derating factors?

I am essentially doing this already with the extension cable.

Just because it works does NOT mean it's safe or legal.
 
G

griffbabe

Why cant I put a plug on an armoured cable?

Because you can't.

It physically will not fit, and there is no facilityy to earth the armouring with a plug.

Ok thats easy to understand, If physicality is the issue I could terminate into a junction box and come out the other side with a plug friendly guage cable?

And why is it too small, should be good for 25amps right?


No. Have you taken into account permitted volts drop and derating factors?

I am essentially doing this already with the extension cable.

Just because it works does NOT mean it's safe or legal.

I suspect that however which way I do this it will not conform to regulations unless I use an electrician. I do think it should be pretty darned safe though, how about if I use a plug in RCD adapter on the house socket?
This then would mean the cabin would trip if there was an issue in the cabin and the adapter would trip before I overloaded the house socket.

PrenticeboyofDerry says I will get 2990 watts off a 13amp socket...somwhat more than I need.

I think in the winter with heating I'll be peaking at 2600 watts.

The unit would be my only personal space and always powered off when not inuse, ie its either isolated from the house or switched off altogether.
Its really a glorified shed so as long as I'm mindful of the dangers I'd like avoid too much legislation, its not a public building.
 
Joined
31 Mar 2006
Messages
20,002
Reaction score
1,380
Location
Leeds
Country
United Kingdom
Oh well if it's not a public building an unsafe installation won't kill you, so crack on.

We all know that no one has ever been killed at home by botched wiring. :rolleyes:
 
G

griffbabe

I'd like to find a practical balance of safety and the budget I have available.
I dont want dodgy wiring which is why Im asking for advice here.

Is anyone prepared to tell me why an RCD in the cabin and one on the house socket would not be sufficiently safe considering as well that I will draw an absolute max 2600 watts, somewhat under the threshold.

Happy to learn.
 
G

griffbabe

By the way the 'run' is about 16meters cabin to house socket
 
Joined
30 Jun 2009
Messages
21,627
Reaction score
2,567
Location
Londonderry
Country
United Kingdom
I'd like to find a practical balance of safety and the budget I have available.
I dont want dodgy wiring which is why Im asking for advice here.

Is anyone prepared to tell me why an RCD in the cabin and one on the house socket would not be sufficiently safe considering as well that I will draw an absolute max 2600 watts, somewhat under the threshold.

Happy to learn.
The safest option would be to first test that the cable is still fit and safe for continued service, otherwise a total waste of time.
Then forget the plug-in option and have it correctly hardwired, as SWA just ain't going in to a plug.
The fact you have two RCD on circuit does not improve the safety aspect.
As in theory they should both trip at the same time, which would still give you power failure within the house, unless you used time delayed RCD or a more sensitive rating.
The up shot is that safety is paramount regardless of cost, too many bodged hash ups as it is, you are asking for trouble if you do not commit to safety as a priority.
 
Joined
30 Jun 2009
Messages
21,627
Reaction score
2,567
Location
Londonderry
Country
United Kingdom
By the way the 'run' is about 16meters cabin to house socket

That should be fine as far as voltage drop is concerned, is there anyway you can connect directly to the consumer unit. If SWA enters house you could then go in to an adaptable box then run T&E to CU. or continue the run in SWA. If the complete run is in SWA, you could avoid RCD protection at board but you must then have it at the cabin for the sockets.
 
G

griffbabe

By the way the 'run' is about 16meters cabin to house socket

That should be fine as far as voltage drop is concerned, is there anyway you can connect directly to the consumer unit. If SWA enters house you could then go in to an adaptable box then run T&E to CU. or continue the run in SWA. If the complete run is in SWA, you could avoid RCD protection at board but you must then have it at the cabin for the sockets.

Sorry, when you say consumer unit what is this? House circuit breaker board?
What is T&E?

All sockets in the cabin go to an RCD unit already.
 
Joined
10 Mar 2007
Messages
10,577
Reaction score
2,224
Location
Poole, Dorset
Country
United Kingdom
Shoving an RCD onto a shoddy, dangerous mess does not magically make it all safe and compliant.

In some instances it might add a degree of protection against certain types of fault.
In others, it will do nothing.

As for the cable - 16m of 2.5mm would probably be suitable, but as this cable already exists in an unknown state it will certainly need testing, and in reality for only 16m length it would be better replaced with a new piece.

Both ends will need to be properly terminated, which rules out any kind of plug arrangement.

Then there is the type of earthing to consider, where this cable will be connected in the house, and that all of this is notifiable so it's on with the lawbreaking as usual.
 
Joined
27 Aug 2003
Messages
69,782
Reaction score
2,884
Location
London
Country
United Kingdom
I have a portacabin
Is it an exempt building in Schedule 2 of the Building Regulations?


Its a 2.5mm armoured cable which seems heavy enough.
That's easy enough for you to check:

1) Why cant I just stick a plug on the armoured cable and replace the extension cable with it.
As the others have said, no - not physically possible.

Read the Wiki article and you'll see why: http://www.diynot.com/wiki/electrics:swa-gland
 

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Sponsored Links
Top