Interesting discussion today with WPD, (My favourite DN0 ) with regards to extending an existing 3.68kW system.
One pole, two overhead wires (single phase) two connections at the top of the pole to two seperate supplies, one terminates at the base of the pole, the other 10 m from the base, two seperate MPAN's.
Customer originally had one MPAN, one supply, requested the second one for an other building (workshop / sunlounge) in September last year, DNO agreed to supply and also said don't connect to the new supply until after 21st Jan becasue we're going to put new poles up and change the transformer (aka strengthening works).
We connected and post notified a 3.68kW system just before Christmas on the original MPAN and I got the connection approval letter at the end of last week. (Not quite like the black hole of SSE !! )
As customer wants to add another 3.68kW system, I called the area planner / engineer to ask him if it mattered to them which MPAN we connected the 2nd system up to as either would need a Stage 2 application and they both feed the same phase.
2 Interesting outcomes:
1) The transformer for the upgrade was delivered to site on Monday and then taken away today, when asked why, they said, because there's some PV been / being connected to the system and we need different / larger transformers ...
2) When discussing which MPAN to connect to, the DNO engineer was really concerned about voltage drop (rise), and I guess based on V=IR, the same cable with twice the current will have twice the voltage drop, so push up the generator voltages.... He was especially concerned about the drop between the top of the pole and the termination point at the consumers end, looking at the size of the incoming cables - I think I see why! Although 100A supply fuse and 25mm tails, the incoming is definitely smaller than the tails.. He was actually more than happy that we connect to the 2nd (new) supply, and even went so far as to say that so long as we don't commission it until after the 21st Jan,then we should just submit a post install (Stage 1) notification. However, because the owner could use the extra generated power, (the sun room / workshop will consume diddly squat when it's generating, and will need an EPC..) connecting both to the one (original) MPAN would financially more than make up for the small drop in Feed In Tarrif (FiT provider has already confirmed 2 x MPAN's = 2 @ full / <4kW rate), DNO engineer has now gone away to work out the implications of putting it all through one MPAN.
Notes:
1) All this without filling a form in yet
2) They are being as helpful and co-operative as any one could wish for.
Moral:
Talk to them, get them on your side and it's suprising what they'll do for you.
In this business it pays to make the DNO your friend.
Footnote:
Why do all our installs have twists, turns and complications like these?!!
One pole, two overhead wires (single phase) two connections at the top of the pole to two seperate supplies, one terminates at the base of the pole, the other 10 m from the base, two seperate MPAN's.
Customer originally had one MPAN, one supply, requested the second one for an other building (workshop / sunlounge) in September last year, DNO agreed to supply and also said don't connect to the new supply until after 21st Jan becasue we're going to put new poles up and change the transformer (aka strengthening works).
We connected and post notified a 3.68kW system just before Christmas on the original MPAN and I got the connection approval letter at the end of last week. (Not quite like the black hole of SSE !! )
As customer wants to add another 3.68kW system, I called the area planner / engineer to ask him if it mattered to them which MPAN we connected the 2nd system up to as either would need a Stage 2 application and they both feed the same phase.
2 Interesting outcomes:
1) The transformer for the upgrade was delivered to site on Monday and then taken away today, when asked why, they said, because there's some PV been / being connected to the system and we need different / larger transformers ...
2) When discussing which MPAN to connect to, the DNO engineer was really concerned about voltage drop (rise), and I guess based on V=IR, the same cable with twice the current will have twice the voltage drop, so push up the generator voltages.... He was especially concerned about the drop between the top of the pole and the termination point at the consumers end, looking at the size of the incoming cables - I think I see why! Although 100A supply fuse and 25mm tails, the incoming is definitely smaller than the tails.. He was actually more than happy that we connect to the 2nd (new) supply, and even went so far as to say that so long as we don't commission it until after the 21st Jan,then we should just submit a post install (Stage 1) notification. However, because the owner could use the extra generated power, (the sun room / workshop will consume diddly squat when it's generating, and will need an EPC..) connecting both to the one (original) MPAN would financially more than make up for the small drop in Feed In Tarrif (FiT provider has already confirmed 2 x MPAN's = 2 @ full / <4kW rate), DNO engineer has now gone away to work out the implications of putting it all through one MPAN.
Notes:
1) All this without filling a form in yet
2) They are being as helpful and co-operative as any one could wish for.
Moral:
Talk to them, get them on your side and it's suprising what they'll do for you.
In this business it pays to make the DNO your friend.
Footnote:
Why do all our installs have twists, turns and complications like these?!!