Armoured mains cable sizing question

[CMW]

I need to run mains single phase power to some new land we have bought, a distance of about 150 metres from my workshop with a decent mains power feed into it. I want to use 3 core armoured and bury it. I need to run a normal 13 amp socket at the field end. What size cable do I need, and is it readily available in more than a 50 metre uninterupted length? On Ebay most seem to be advertising 50 metre lenghts, I'd rather not have to try and make a waterproof undergound joint.

Are there waterproof lockable boxes available, I'd want the 13 amp mains power socket in it, and a 12 x 10 x 6 inch electric fence energiser in it, too?

Thanks.

 

[securespark]

Well, if the load is just 13A and no more, with 16mm² SWA you get a VD of 5.46V on 150m

However, you need more than 13A, so I would say 25 min...

 

[Adam_151]

My thoughts:

You could probably scrape by the Zs on a B16 with 16mm 3c dending at Zdb at shed, but as its going to have to be 30ma rcd protected, I'd probably do it at source and make it 2c (armour over that length as cpc would really cock up your Zs)

If its TNCS you ought to loose the supply earth and make it a TT system* for the socket, with a separate electrode (actually if you did this and the supply was TNS it wouldn't cause any harm, but TNS doesn't present the issue that warrents it as TNCS does)


Masterseal socket on a post with rotary isolator below it? isolator is lockable in off position and get a big enough one and you can use it to switch down to a cable CSA that you can actually terminate in the socket!

10mm² armour would be adequate for 16A from a V/D pov by my calculations (I fully expect this to raise some eyebrows!)

*RCD protected supply into another rotary iso on outside of shed, end TNCS earth there, earth electrode below to provide earth to armour might be the way i'd do it.

(the normal way with a building submain eyc is to put the electrode at the far end, but would seem a tad 'weird' to put one in the middle of a field, and also means you haven't got an exported TNCS only a gland cover away)

CW glands to be used


I'm tired so i've probably cocked up or missed something....

 

[Lectrician]

Or if it is only going to ever be for the fence controler and nothing else, hard wire the controler, and base your cable calc on the loading of that - which is sweet fa. Cable would be ALOT smaller.

ALL cables are available in ANY length.

Dont buy from ebay - carriage would be more than the cable is worth!