Swa Cable Size

[smith.james0]

I am looking at the size of swa cable I would need to feed my garage, at sometime in the past someone has used 1.5mm twin and earth hung between the house and garage   

I am looking to feed the garage directly from the cu in the house to a cu in the garage. The garage is about 18 meters away (the garage is only 1.5 meters from the house but the cu is the on the other side of the house), the cable would be run above ground attached to the house wall then, attached to a wall to bridge the gap between the house and garage. In the garage there are 3 double sockets, 3 x 6' tubes, supply to the decking lighting and an outside socket.

Can anyone advise?

James

 

[m4tty]

What will the total load be in the garage ?

 

[SLIPSHOD & SLAPDASH]

If you wire a 10mm 3 core it will be suitable for near enough  all purposes.

 

[steptoe]

If you wire a 10mm 3 core it will be suitable for near enough  all purposes.

Id agree with that, maybe even a bit overkill,

but, unless you use it for a commercial workshop, or some BIG welding kit, that should cover most bases including VD and Zs under most conditions.

 

[SLIPSHOD & SLAPDASH]

Id agree with that, maybe even a bit overkill,

but, unless you use it for a commercial workshop, or some BIG welding kit, that should cover most bases including VD and Zs under most conditions.

Exactly 

Including any possible  earthing/bonding/tt/pme/tns/pmt

 

[Evans Electric]

10mm ....  Top of my head I think...   Blimey !      No info given but maximum load probably  5 - 10A . 

 

[Andy™]

400mm², doubled up for good measure?

 

[smith.james0]

What will the total load be in the garage ?

Mainly power tools drill/ saws 1000w, in winter I might use a 2k fan heater, total lighting will be no more than 250w I do have a spare fridge that might get used, decking lights 3w. Total 3.5k - 4k watts

James

 

[steptoe]

OK, some advice,

what is your garage made of?

I'd be looking more at insulation before id be using a 2kW fan heater,

my mate has a well insulated garage, about 25' x 14' and heats it with 2 x 300w tube heaters on stats,

and its never cold in it, ok, so its not warm, but its for working in, not sitting in, he also has a little 1kW oil filled rad for hard winter.

 

[binky]

Mainly power tools drill/ saws 1000w, in winter I might use a 2k fan heater, total lighting will be no more than 250w I do have a spare fridge that might get used, decking lights 3w. Total 3.5k - 4k watts

James

so you are looking at rough 16A, allowing for a little extra we could call it 20A and run in 4mm. Don't forget RCD protection for sockets, and you need to consider the earthing arrangments.

 

[smith.james0]

For earthing I was going to use 3 core, using one for earth and earthing armouring. 

James

 

[apprentice87]

Aha, not as simple as that..... What earthing system does your house have, and what system were you thinking of using in the shed?? This COULD have a huge impact on cable size...

john..

 

[smith.james0]

The house is TNCS, I was going to use the earth at consumer unit for the garage.

James

 

[steptoe]

The house is TNCS, I was going to use the earth at consumer unit for the garage.

James

please dont,

its really not that simple,

in fact,

it could be VERY dangerous, lethal even ,

its really not something that should ever be contemplated without a VERY thorough knowledge of the earthing system.

 

[smith.james0]

Looking at it again, I will earth the armour to the consumer unit in the house, leaving the garage consumer unit divorced. Then use a earthing rod to earth the garage. The only external piece of metal is a strip along the top of the asbestos roof which will need earthing, and the is no gas/water pipe. 

James 

 

[Andy™]

{Moderator note -  be nice Andy}

 

[binky]

and does this get Steps approval????? Wouldn't worry about the metal roof strip personally

 

[SLIPSHOD & SLAPDASH]

{Moderator note -  be nice Andy}

 

[steptoe]

and does this get Steps approval????? Wouldn't worry about the metal roof strip personally

doing something because you 'think' its what should be done, and not knowing why you are doing it would never get my approval,

the OP appears to be simply doing what he thinks is the consensus with no idea of the implications, or why-fors

 

[Evans Electric]

Looking at it again, I will earth the armour to the consumer unit in the house, leaving the garage consumer unit divorced. Then use a earthing rod to earth the garage. The only external piece of metal is a strip along the top of the asbestos roof which will need earthing, and the is no gas/water pipe. 

James 

Aaaaagh !   He used the A word ............who cares about the earthing ...the roof'll kill ya      ( Apologies:   Butch Cassidy & the Sundance Kid )