probably a stupid question but advise would be great

[stubo300]

i am going to finish my first pv installation tomorrow, and i have a question about the meter.

so the way i have wired the pv panels from the consumer board is:

16mcb from consumer board
AC isolator
Generating meter
Ac isolator in loft
inverter
dc isolators
pv panels

my question is the 'generation meter' do i wire it so the cables coming back from the inverter are on the input of the meter or do i wire it so the supply coming from the mcb is in the incoming side of the meter

 

[SolarCity]

The inverter to the meter is the SUPPLY and the meter to the consumer unit is the LOAD.

 

[yellowvanman]

Can I also point out, maybe you should put the 1st ac Isolator on the inverter side of the meter, your MCB can be the isolator for the other side.

So in effect you have the following sequence:

16mcb from consumer board
Generating meter
AC isolator
Ac isolator in loft
inverter
dc isolators
pv panels

 

[stubo300]

thanks for the quick reply

 

[Ramjam]

Your proposed circuit order is consistent with the DTI guide, moving the AC isolator is not consistent with the guide. It is however not an explicit rule, simply how they show it in their schematic. I''d stick with your original design as the AC isolator then isolates the entire PV 'system'. The purpose of the AC isolator is to provide fast, easy emergency isolation so I'd want the whole circuit taken down. Do whatever you like though!

 

[edrobbo8]

Sorry to go O.T., but if you were to run a 6mm SY cable from the inverter to the C/U would this be adequate in terms of protection? It would be run along the top of the wall inside a barn, around 15 metres max. Thanks

 

[gr7]

I got pulled up at my MCS assessment today for putting the meter before the isolator, tried arguing the case as the 3 phase schematic (on the same page of the dti guide) shows the meter before the isolator, inspector was having none of it and insisted that the wiring is changed.

 

[Markc]

I have to say our gen meters are aways between the AC isolator and MCB. I see it make no real difference as in a majority of cases they are going to be adjacent to each other, At the consumer unit. We have been inspected doing just this also (Not that I think our inspector even knew what PV was at the time). I would say as long as its ALL there whats the issue?

 

[JulianC]

Gen meter always between AC isolator and MCB here too. Makes no difference either way and I would be delighted to hear an MCS inspector's reason why it's not correct tbh.

 

[gr7]

He showed my the schematic on page 8 of the dti guide saying that the installation had to comply with that. He was a decent knowledgable chap and otherwise very helpful, I just could not persuade him that the diagram next to it shows the meter on the other side of the isolator thus making my install compliant. It only took 5 minutes to alter the cabling which is a lot quicker than going through an appeal process.

 

[Worcester]

Ok so if you have the inverter right next to the connection (in a garage) and so we've only got one AC isolator then where would he have put it?

 

[gr7]

Funnily enough it was in a garage, right next to the garage distribution board (sub main fed from house) with only one AC isolator.