Farm advice

ondarack

My uncle has about a 50m run from the house to the dairy. We need to take up the cable as he's doing some building soon and he'll need to keep the power. Is it possible to join SWA out on the field? I think it is so what size cable do I need to finish the rest of the 30m run feeding a 50amp fuse? All advise welcome

M cebee

you can join no prob with a resin joint

10 may be enough(16 is better usually)

depends on the demand,type of loads(welders etc.)

and you need to match it to the protective device(mcb/fuse) at the supply side

you'll need a sparkie to scope it out anyhow

Randyleprechaun

Over that distance with a load of 50A you will IMO be on the limits of the 16mm2 and no expansion will be posibble ever.

You should calculate the loads exactly allowing for expansion if required.

As a previous poster said you need to ensure that the cable is protected by the MCB /Fuse on the supply side.

However that protective device can be made smaller if it suited you to use smaller cable ie. when you have load calculated.

In my experience, if it's a dairy the load is going to be quite big at times so I'd say you'd be better running 16mm2 minimum and thinking about larger.

M cebee

'VD' seems to be approx 10-12V at 50amp for 10sq

max Zl for a 50amp neozed seems to be 0.6ohm-i think that's measured at the sub-board

you'd be measuring the loop-impedance at the 'supply point' first anyhow
before buying cable

bigger cable may be needed for any 'disturbing loads' and to keep the loop-impedance down