agricultural shed

[trickyb]

Hi im use to domestic instalations and and have a customer thats changing his catenery wire supply to his agri sheds to underground(3ph) power company doing job but want me to give them a letter saying what box he needs at supply end in shed? not done alot of 3ph would i use a 100A tpn isolator ? mccb? it is only supplying 13amp sockets /lights. I know it depends on distance from meter etc . just want to know whats the norm in isolator department? :confused5:

 

[telectrix]

why is he running 3 phase just to power a few sockets and lights? if it's for possible future use, you could just fit a "garage board" on 1 phase for the present needs.

 

[Rauer]

Why not just run single phase to a 4way RCd board in a sarel box?

 

[spud1]

I would install a 3 phase RCD and IP enclosure and create a segregated TT system for this shed (being detached & Agricultural) and use 1No. phase for now to supply a single phase main switch, 2 way, IP rated consumer unit to serve sockets and lights. (Assuming 3 phase for future machinery/loading requirments)

 

[trickyb]

Hi just taking 3ph for future save digging the yard up agin ! will power company put a tpn isolator on end for me to work from? thanks for input lads

 

[Engineer54]

Are you asking for the DNO requirement here, ie, ...a customer KVA load request??

You say ''Sheds'' as in the plural, are you saying that this underground cable is supplying a DB in one of these sheds, that will then be supplying other sheds/outbuildings?? Your not giving anywhere near enough information here, to know what your actually asking advise on. So all you'll get, is stab in the dark guesswork!! lol!!!

It's very unusual for a UK farmer to cough up money for something he doesn't need!! lol!! So i would make very sure, that he doesn't have some sort of future plan, where he will need a 3 phase supply....

 

[Engineer54]

I would install a 3 phase RCD and IP enclosure and create a segregated TT system for this shed (being detached & Agricultural) and use 1No. phase for now to supply a single phase main switch, 2 way, IP rated consumer unit to serve sockets and lights. (Assuming 3 phase for future machinery/loading requirments)

So how do you know the supply from the DNO isn't TN-S?? the OP hasn't mentioned anything about the earthing that's present....

 

[trickyb]

Hi thanks spud1 sounds good way to me. you,ve all been very helpful

 

[spud1]

Even if the supply was TN-S would you not create a local TT system in an agricultural installation to limit the danger of differing potentials between earthing system and ground potential (I.E danger to livestock)

 

[JD6400]

Are you asking for the DNO requirement here, ie, ...a customer KVA load request??

You say ''Sheds'' as in the plural, are you saying that this underground cable is supplying a DB in one of these sheds, that will then be supplying other sheds/outbuildings?? Your not giving anywhere near enough information here, to know what your actually asking advise on. So all you'll get, is stab in the dark guesswork!! lol!!!

Hi E54 , that bit about the uk farmer did make me chuckle , thanks for that !
I would however go TT like spud , as you would all most definitely not have a grid in the floor to bond to .