Poor Solar PV Installation ??? Expert Help Needed

[Bucks]

I've just checked again and it is suitable just needs the four panel string start up voltage lowered.
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Sorry I had deleted the post that you have just answered, as I was looking at the PVI-3600 & not the PVI-3.6-OUTD

 

[Bucks]

After our installer has been in touch with Power-One, we have gone for the PVI-3.6-Outdoor inverter.

Their technical guy said that the 4 & 12 would work with the voltage reduced to 126, but the system would work more efficiently if we had a string of 5 and a string of 11 and reduce the voltage to 160.

So he is recommending that we wire one of the top panels into the same string as the 4 lower panels.

 

[SolarCity]

In that case, I would recommend that you seek out the panel which will receive most unavoidable shading on the upper roof and make that part of the lower roofs string.

Good work from your installer. Great to see him improving the system for you. I can't fault him for that.

 

[Bucks]

We are only as good as our last job , and putting aside why your one ended up with the issues that it did ?
It is their chance to redeem their selfs , i have to admit i tend to judge a company not on how they preform day to day but more so on how they preform when faced with a cock up / problem , how ever it was created !
So here's hoping it goes well ?

Well said and I agree completely! Let's hope the OP's installer will now give the OP the installation he wanted.

Fair play to your installer. At least he is going to good lengths to sort the issue.

Good work from your installer. Great to see him improving the system for you. I can't fault him for that.

I cant agree with all the above comments more, he is pulling out all the stops to get the system sorted out for us, I'm pretty confident we will get there in the end.

 

[Bucks]

In that case, I would recommend that you seek out the panel which will receive most unavoidable shading on the upper roof and make that part of the lower roofs string.

That is what I pretty much asked eariler Note: the soil pipe & ariel will be sorted somehow!

Also would it not be suitable / recommended to connect two of the top panels that are shaded by the boiler flue to the same string as the four lower panels,

 

[Bucks]

Someone has sent me a email stating "The PVI-3.6 is a transformerless inverter so make sure that pv frames are earthed."

Can someone please clarify this.

 

[MorganPVI]

To ensure DC seperation with the AC side the DTI guide http://www.electriciansforums.net/photovoltaic-solar-panels-green-energy-forum/23511-pv-guide.html advises that the frames of the panels are earth via a ground spike.

 

[Worcester]

In addition if he is using the Power-One 3,6 OUTD (or any other transformerless inverter) he MUST ensure that the routing of the AC cable doesn't need to be RCD protected.

If the AC cabling needs a 30mA RCD neither Type A or Type B will work, and no protection will be provided.

So the AC cabling MUST be installed so as not to need RCD protection.

I'll tell you all more of the facts later (need a day to write it all up) in essence if he is using a TL inverter, NO type A RCD will work under DC fault conditions (nothing to do with the Inverter - what power-one, SMA et al have said is true - as far as it goes) and even a Type B RCD will 'nuisance' trip at 30mA

If the AC cabling cannot be installed such that 30mA RCD protection is not required then it'll have to be a Transformered Inverter and we're back to square one.

 

[Bucks]

Thanks Guys,
I'm all a bit confused now as I don't really understand what you are saying about the RCD business, I know that the whole property is protected by RCD.

 

[SolarCity]

Presumably you are not on a TT system - normally when you have are supplied by an overhead cable. Judging by the age of your house and the urban location, this seems unlikely. In these instances, your earth is obtained from an earth rod. This doesn't give great Ze (external impedance) readings so the RCD is there to offer ADS (automatic disconnection of supply).

It sounds more likely that your consumer unit is protected by RCDs - especially likely if you have had a consumer unit upgrade in the last few years.

If this is the case then a good solution would be to have a seperate consumer unit installed which is not RCD protected. This should be pretty straightforward to achieve.

 

[Bucks]

It sounds more likely that your consumer unit is protected by RCDs - especially likely if you have had a consumer unit upgrade in the last few years.

100% correct I installed it a couple of years ago when we extended the house.

If this is the case then a good solution would be to have a seperate consumer unit installed which is not RCD protected. This should be pretty straightforward to achieve.

That is exactly what I was wondering, as before I put this Dual RDC CU in, we had two one with RCD protection & one without, not a lot of room in the cupboard where all our electrics are though.

So just to confirm this PV system needs to be wired into a Non RCD CU (at the moment it is wired into the RCD)?

Also the PV Frames need to be earthed? could they be earthed to the earth near the meter as that would be a lot easier in our situation? or do they have to be earthed via a ground spike somehow?

 

[SolarCity]

If you take a picture of your incoming and post it on here, I should be able to give more of an idea if you need a spike or not.

And to confirm, yes, install the PV system on a CU which is not RCD protected. If space is limited then this may be tricky.

 

[Bucks]

Picture as requested THANKS, we will be able to fit a small CU with a bit of juggling other things around.

 

[SolarCity]

Okay, looks like a PME system to me. Get the installers to fit an earth rod. It may even make the cable run easier.

 

[Worcester]

@BiggsSolar, we had one recently looking just like that on closer inspection it turned out to be a really old TN-S so it meant bonding back to the cnsumer earthing terminal so it may be worthwhile just double checking.

@Bucks, it should say PME or similar somewhere near it (hopefully) - I couldn;t quite see from the photo. In a TNS system - the 'Earth' is connected to the metal braiding / sheathing around the main incoming cable.