3phase cable rating

[SparkyTris]

connecting up an 80KW three-phase wind turbine, I calculate that the maximum current will be 112 Amps in each phase. (400V inter phase)

I am trying to determine the correct conductor CSA for this, in order to purchase a run of cable.

I'm aware that it will depend on length (this may be up to a kilometre)
I wonder what other factors the derating might depend on

the intention is to trench the cable.

Comments & help gratefully received!

 

[holmslaw]

..

 

[plugwash]

moving that much power that kind of distance at LV just doesn't make sense. Time to get someone with HV experiance involved IMO.

 

[ban-all-sheds]

Could you not step it up to 11kV? Smaller cables, less VD problems...

[EDIT]Doh![/EDIT]

 

[lambert]

Just a thought,

 

[riveralt]

Just a thought,

About whether he has moved his windmill closer to the house or are you thinking about the 380 plus days that have elapsed since this was posted?

 

[lambert]

hahaha It just seemed ridiculous. i was looking for something else when i came across this post. £39k for cable. wow and that was last year !

 

[ericmark]

On the Falklands we set up a village and this involved loads of port-a-cabin type units.

Because of the power and distance 12 x 750kVA from memory we had an array of 3.3kV transformers stepping up and down. However when we had a power out it was really hard to get the first 6 generators on line before we could switch on the first transformer.

The in-rush resulted in needing 6 generators on line before first switch was put in. This I see as a problem with wind turbines. So in real terms they would like the permanent generators installed at Mount Pleasant need to generate at 3.3kV and only use step down transformers. In fact likely they could connect into the grid at 3.3 or 11kV.

This would be all worked out at the design stage and would need some careful calculations. If you went onto the IET forum you may find someone who has done this type of work but this is not DIY and really not the sort of thing to ask on a DIY forum.

Even with my degree and 40 years plus experience I would be wary of doing this sort of work. The insurance you would need to cover if you get it wrong is rather expensive and this sort of work is not normally done by the sole trader.

 

[ban-all-sheds]

Eric - I don't suppose that after a year he's still mulling over what to do.