R
rosewood
a customer has asked us to wire up a caravan park thats he's building on some of his land but we're struggling to decide on the size of the sub main to power it all.
he has 2 fields which will each have 20 caravans in them. The plan is to supply a busbar chamber in a mains room at the start of the first field, which will supply a distribution board for the first 20 caravans. the supply then needs to get to the second field with another board for the next 20 caravans. The caravans are fed by purpose made hook-up points which supply 2 caravans, so there will be 10 circuits from each fuseboard, each supplying 2 caravans. For once the load isnt the problem as it should only be 100A per phase on a 4 core SWA, but the volt drop is another matter. the first field is 180m from the origin, and the second field is another 120m from that.
it looks like we need a 95mm to get to the first field (dropping 6.39v along the way) and a 70mm from there to the second field (dropping another 2.86v) for a combined volt drop of 9.25v, allowing a little tiny bit of volt drop in the final circuits.
then we hit another problem, the furthest caravan in the first field is 160m from where the customer was planning to have the supply. even on a 6mm armoured we are talking something like another 20v dropped.
so, if we supply the fields with 95mm 4 core SWA we will struggle to terminate it into anything, and even if we managed that we'd need to feed each caravan with maybe 16mm 2 core SWA, which wouldnt terminate into the hook ups. add to that our customer would need the income of a small country to pay for all that copper, we need a better idea.
:dizzy2:
he has 2 fields which will each have 20 caravans in them. The plan is to supply a busbar chamber in a mains room at the start of the first field, which will supply a distribution board for the first 20 caravans. the supply then needs to get to the second field with another board for the next 20 caravans. The caravans are fed by purpose made hook-up points which supply 2 caravans, so there will be 10 circuits from each fuseboard, each supplying 2 caravans. For once the load isnt the problem as it should only be 100A per phase on a 4 core SWA, but the volt drop is another matter. the first field is 180m from the origin, and the second field is another 120m from that.
it looks like we need a 95mm to get to the first field (dropping 6.39v along the way) and a 70mm from there to the second field (dropping another 2.86v) for a combined volt drop of 9.25v, allowing a little tiny bit of volt drop in the final circuits.
then we hit another problem, the furthest caravan in the first field is 160m from where the customer was planning to have the supply. even on a 6mm armoured we are talking something like another 20v dropped.
so, if we supply the fields with 95mm 4 core SWA we will struggle to terminate it into anything, and even if we managed that we'd need to feed each caravan with maybe 16mm 2 core SWA, which wouldnt terminate into the hook ups. add to that our customer would need the income of a small country to pay for all that copper, we need a better idea.
:dizzy2:
