Armoured Cable Thickness?

Hintza

We are currently building stables and I need to run a power supply. I think 6mm cable will do (just) but should I err on the side of caution and get 10mm?

My thoughts on maximum output (not all at the same time) will be:-

Kettle:- (3kW?)
Lights:- 300W
Freezer:- ? (but small)
Clippers:- 200W

I don't have one but if I say used a pressure washer (1.4kW) or similar would I pushing my luck.

Any views appreciated.

Oh one other thing I presume I want 3 core?

Andy_L

How long is the cable run?
How is it routed? Buried, Clipped to wall, suspended from a catenary?

Hintza

Sorry thought I had mentioned length. That will be 60m and buried coming in at gable end before going up wall to roof space before dropping back to consumer unit.

Ich_2

It isn't all about the load, it is also about the voltage drop along the cable.
You need to know the length & the volt drop per metre of cable. The overall figure cannot exceed 5% of the nominal mains voltage.
Have you looked at the earthing arrangements, what sort of earthing have you got, can it be safely and within the regs exported to the stables.
Work of this sort should be notified to the local building regs department, properly tested and certified.

Quiet_Spark

60m of 6mm² PVC insulated SWA will withstand a continuous load of 6KW in the configuration you describe.
You will only need 2 core as the armour is the earth conductor.

Hintza

Thanks guys, that's a great help. Looks like the 6mm will be ample, I thought it was but just wanted to check I wasn't trying to skimp.

Ich_2

Which will give a volt drop of 4%, If your earthing is TNC-S and you intend exporting it you need a MINIMUM of a 10mm2 earth, 3 core 6mm2 with one core & the armours being used as the earth will just comply

keystone

Ich wrote: »

...........as the earth will just comply

Just being the operative. Perhaps TT for the stables would be best.

Cheers

Hintza

OK guys you are now confusing me again (last two posts)...eek.

keystone

Quick google on earthing systems will help you rather than a detailed explanation but basically with TN-C-S (known as protective multiple earthing (PME) in the UK and is where the combined neutral-and-earth conductor of the supply is connected to real earth at many locations) in your house you will be exporting the earth to the stables and it will only just comply with requirements using 6mm cable. Having a separate and independent TT (terre - terre or ground to ground) earth system for the stables using a nice big conductive stake driven into the ground. But with TT ALL circuits must be RCD protected.

Cheers

Ich_2

I would suggest that you need to learn a lot more about electricity, or employ an electrician.
At the end of the day it is a stable so if it goes wrong and you end up with a dead horse or worse a person, the cost of an electrician would seem minor.

There is nothing stopping you doing the excavation and donkey work under supervision to save costs