Solar PV Wiring Query - Compliance with BS 7671

[Buck-Toof]

Where to start, there is SO much wrong with that installation..

Thank you Worcester, for your advice and your time. I'll wait 24 hours, give the installers and my landlady a chance to sort this out. If they do nothing, then I'll call Napit.

 

[Gavin A]

tbf I've seen worse, and I don't see that it's actually immediately dangerous as such.

let the company come back and rectify it rather than kicking up a fuss with napit etc IMO. If they won't then fair enough, but give them a chance to sort it out

 

[Buck-Toof]

Well, the installers were back today, after landlady complained. I was at work, but here are latest pics....
Seems good enough. Still no labels on anything. They said they'll send an EIC certificate to us later on.

 

[whinmoor]

Wow - look at that isolator on the timber! Have you checked if they actually work? Not many cable clips in the wall either.

It's not compliant without labelling so you could get them back to resolve that.

It's a bit messy and I'm not sure SAJ will be using this particular effort for their marketing.

The 2.5mm T+E is the bare minimum. It should be enough if the cable run is reasonably short.

Sounds to me that the lady got a pretty poor deal and shoddy workmanship but it'll probably work. Make sure she gets an insurance-backed workmanship warranty.

 

[Gavin A]

very unlikely that 2.5mm2 cable will comply with the requirement to limit volt drop to under 1% for a 4kW system with inverter in the loft.

This means the system is far more likely to suffer from the inverter tripping out due to over voltage issues at times of high generation and low on site consumption, particularly if there are other solar PV systems on the same phase on the street. In that scenario the system with the 2.5mm2 cable will trip out while the neighbour with the 6mm2 cable won't.

 

[Buck-Toof]

very unlikely that 2.5mm2 cable will comply

Thanks Gavin. Yes, SAJ manual says use 10 AWG / 6mm^ on AC side.

It’s an east-west array, 2x 8 panels. I think its power output will never be more than 2 kW, even in mid summer.

The house is a 3 storey terrace, tall and narrow. And the AC cable run is 8 meters, in plastic conduit (not steel like I said earlier), down the outside of the house, from eaves to CU.

I’ll mention all this to my landlady (again) and leave it in her hands. Thanks to everyone for the advice, especially the lads from Leeds.

 

[whinmoor]

Thanks Gavin. Yes, SAJ manual says use 10 AWG / 6mm^ on AC side.

It’s an east-west array, 2x 8 panels. I think its power output will never be more than 2 kW, even in mid summer.

The house is a 3 storey terrace, tall and narrow. And the AC cable run is 8 meters, in plastic conduit (not steel like I said earlier), down the outside of the house, from eaves to CU.

I’ll mention all this to my landlady (again) and leave it in her hands. Thanks to everyone for the advice, especially the lads from Leeds.

Why not get the installer back again and ask them to comply with the inverter's instructions manual which specifies a 6mm cable? They can bring a sheet of labels with them to do that bit correctly as well.

We would probably use an SWA down the outside wall rather than their method.

I think it will easily exceed 2kW at times. We have some e/w splits which clearly do more than that, hitting and exceeding 3kW at times. If the pitch is steep, 2.5kW might be a struggle.

But, then again, we wouldn't be using 2.5mm cable on the job to start with.

 

[Worcester]

These guys have already had an opportunity to put it right and still haven't bothered.

Now think what the situation would be if no FiT and so people not "bothering" with MCS ...

Give 'em all a horse, they'll feel at home on it ...

If one of my apprentices installed a system to those standards, they wouldn't be employed the next day. Even they know far better than to do it like that.

I can see over a dozen non-compliance items in the second set of photos and description.

 

[Buck-Toof]

These guys have already had an opportunity to put it right and still haven't bothered.

Yes, I agree. I put everything I learnt from this forum in a nice simple list for them. Labels were No.3 on the list. They just can’t be bothered.

I think they’re doing 5+ installs per week. So I’ll email NAPIT and suggest NAPIT has look at some of their recent work.