Solar PV Wiring Query - Compliance with BS 7671

[Buck-Toof]

Hi, I'm a new member; just joined the forum. Thanks for taking the time to read this, would appreciate any advice...

My landlady has just installed a 4kWp solar PV system in the house I rent, and I think there are problems with the wiring:

1. There are no isolation switches anywhere in the PV circuit - none. No DC disconnect, no AC isolation switch, nothing. It's all wired directly from solar panels to inverter to CU. Do the wiring regs allow this?

2. The AC supply from the PV system is wired into the load side of an immersion heater MCB (16A) and the neutral busbar of the CU. Is this ok, or should it be on a separate 2 pole MCB?

3. The are no labels or warnings signs of any kind, anywhere on the PV circuit. Again, is this acceptable?

4. The installers have not done any testing and they have not provided an EIC.

I'm not an electrician and I'm not sure if the above is ok - as a kind of minimum acceptable standard. Would someone be kind enough to confirm one way or other?

Thanks lads
Buck

 

[GMES]

Hi Buck and welcome to the forum.

 

[whinmoor]

Sounds well dodgy. Advise her not to pay until the installation is compliant. Is it definitely complete and commissioned? Maybe the installer plans to return to finish off?

The DC isolator might be integrated into the inverter. Some systems don't need DC isolators. All systems need at least one AC isolator. If the inverter's in the loft, it should have two.

There should be lots of labels. We use approx 12-15 on every job. There should certainly be an EIC. Has she been given all her paperwork such as MCS certificate?

Can you post some photos of the installation?

 

[Worcester]

Photo's please. It should be on its own MCB

What no meter?

Dropbox and a link will do.

From your description, it doesn't sound as though it is either BS7671 or MCS compliant.

Find out which organisation (NICEIC, ELECSA, NAPIT) the installers are registered with - or name them here and we can check them out for you, and then we can give you the contact details of the relevant organisation to call.

There should be some contact details of the installer somewhere about...

 

[Gavin A]

doesn't sound compliant, although it probably could be argued that it's not unsafe as both devices are current limited devices and only need fault protection that the MCB would provide.

there should be an AC isolator within 3m of the inverter, and dc isolation (though this can be intergrated into the inverter)

 

[Marvo]

Photo's please....

I've just given you full member permissions Buck Toof so you can attach photos to your posts as long as they're not too large.

 

[Buck-Toof]

Thanks for the replies GMES, Whinmoor, Worcester & Gavin A. & thanks again GMES for photo permission.

I will ask Landlady for name of installer. They've left no details in the house. Install was done last week while I was at work.

The system is complete and commissioned, they're not coming back.

She's already paid in full. Cost £7,000. She got a loan, repayable over 5 years. My reckoning is 15 to 16 years to break even.

Photos, as soon as I can, tomorrow after work (7AM start for me).

Paperwork, she has:
- MCS certificate
- FIT application forms
- DNO form - application or approval, I don't know which
- Nothing else

The inverter is a Chinese SAJ Sununo TL Series TL4KA. They've put it in the loft, about 2 inches above the loft floor, right in the corner under the eaves. Fixed directly to breeze blocks. Need to be an acrobat to get anywhere near it. There could be a DC isolator on the underside of the inverter (optional extra on TL4KA, need to check).

The CU is on a wall, ground floor hallway. They've put a Emlite kWh meter, a bit of trunking, that's all.

I think, hope the inverter will auto disconnect on loss of grid-tie, otherwise my CU will still be live with main switch off.

Anyway, I'll get some photos asap. Thanks a lot lads, forums are brilliant!

Buck

 

[Gavin A]

she's paid how much for that?

 

[whinmoor]

I will ask Landlady for name of installer. They've left no details in the house. Install was done last week while I was at work.

Installer should be mentioned on the MCS certificate.

The inverter is about as cheap as they come.

 

[Worcester]

£7k Ouch....

 

[TedM]

SAJ Sununo TL Series TL4KA - may have a DC isolation switch on the bottom - it is an option - but how you would get to it if it is only 2" off the floor of the loft is another matter. Manufacturer states that minimum clearance is 50 cm.

It is also G83 certified so will switch off if grid fails assuming it has been configured correctly.

 

[Buck-Toof]

Hi All and thanks for the replies,

Checked MCS website. Installer is with NAPIT and certified since 2012.

Spoke to my landlady who called installer. They're happy to come back and sort any defects.

Here're some photos...

 

[Gary K]

For a start, the 1.5mm cable is seriously undersized.

 

[Worcester]

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

Call Napit in the morning - 0345 543 0330 Ask to speak to the MCS Compliance Team, explain your concerns, focusing on the safety aspects

Remember you are not the customer, your landlady is and she hasn't appointed you to act on her behalf, so you can only act on your own behalf.

Tel them that you are very worried about the saftey of the installation as you have no instructions, no deatilsof what to do in an emergency, no ciruit diagrams and no labelling and cna they send an engineer out to inspect urgently.

You will have to be persuasive and persistent, don;t hang up until you get a firm date and time for someone to come round.

You will have to tell them the name of the installer and their Napit registration number.

Remember it is most likely that you are speaking on the phone to an admin person, who really justs wants to get you off the line...
Just keep pressing the safety aspects, that your worried about fire risks, you don't know what to do in an emergency etc etc . Don't hang up until your get the NAME of the engineer that will visit and the DATE and TIME that they will come - don't be put off by them saying in a week or so, - force the safety issue.. Scare the s**t out of them that you are worried about fire etc etc..

 

[Buck-Toof]

For a start, the 1.5mm cable is seriously undersized.

Yes, you're right. Thanks Gary K. I hope I've got that wrong. I need to check.

I must have got it wrong. Was the diameter about 1.5mm, so makes it 2.5mm csa.

I found the inverter manual in the loft - for AC cabling it says use 10 AWG which would be 6.0mm csa or 2.5mm diameter.

This is another thing to mention to them.

 

[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.