Any suggestions for Inverter woes?

[Worcester]

Thanks for the reply, I would have liked to take a reading at the inverter but I didn't want to break the isolator housing, is there a simply way to override the openable-only-when-off safety feature of the AC isolator, if you see what I mean? Its a salzer one.

Nope you only want to open it when it's off , that's the idea of the isolator. I would strongly advise you get an expert in to check it for you.

 

[balbecdaze]

Er, I have all the relevant qualifications, accreditations and competencies Worcester. Just not the experience of a wealth of installations like some of you guys. I really appreciate any time spent to help.

 

[whinmoor]

We've never installed one of these outdoors but I know they are IP65 rated. Siting it in direct sunshine is probably not a smart move so could you relocate it or extend the overhang on the cover?

Have you considered replacing this unit with another brand for a few days? If the other brand struggles/fails, you'll know it's not the Eversolar unit at fault and the problem lies elsewhere.

Did you install it in damp conditions? Could it be that there's some moisture in the internals?

How far away are the panels from the inverter?

 

[Worcester]

@balbecdaze, sorry didn't mean to 'dis' you, this is straightfoward trouble shooting.
1) Check actual voltages at inverter - that's where the high voltages are - the drop happens between the inverter and the incoming.
2) No different than testing a CU, - you have exposed conductors then.
3) On most inverters, you can test the voltage (and fire them up) even with the cover off, sorry can't comment specifically on the EverSolar ones.
4) If you can't, then why not temporarily wire in an IP65 rated outdoor socket to the isolator.

5) Most important - check the country settings on the Inverter - it is set to G83/1-1 isn't it?
- Looking at the spec sheet it appears this isn't configurable and despite being set to 264V @ 1.5 secs, the actual trip values in the test were 259.4 even so, that's pretty high.
6) See if the inverter can display the frequency, if it's not overvoltage it may be that. (Very unusual but it may be)

If all else looks OK, I guess some of the components must have failed, so you should get a swap out unit.

 

[balbecdaze]

@ whinmoor, no dampness, installed during a lovely hot weekend, end of july last year. Could there be dampness in the inverter anyway? I guess of course, just from condensation whenever the box is colder than the internals.

Panels are 25m from inverter (well, 25m 6mm SWA plus a metre of the 4mm solar cable the panels themselves use).

Direct sunshine - that is, I think, what I've learnt from this install (at least its at my own house!). I could extend the overhang (have done once already) but to be honest, I think the damage is done. It wouldn't even start today once it was overcast after it had had a bit of sunshine.

I would love to replace the unit with another for a few days (This springs to mind). There is no cash though!

 

[whinmoor]

You could take your inverter to someone else's house with a 4kWp system for a few hours for test purposes?

 

[balbecdaze]

@Worcester, no worries.

1) Yes I'd like to, but I didn't want to actually damage the Isolator housing by trying to twist the switch with the cover off, I was just asking SolarCity for advice on how to do this. I will try your suggestion 4 next time I'm at home during sun!

2) Yeah, I'm very cautious (scared) about working live but it does need to be done sometimes - especially with PV, this is my first PV fault-find so I'm just trying to be extra cautious, hence your excellent suggestion 4.

3) Don't think I can do this with my inverter, I'll wait for a come back from my supplier before I have a go. The possibility was vaguely raised of a replacement after my last phone call, I'll wait and see.

4) I'll do this.

5) Thanks for taking the time to check this out, that's why I wanted to check the voltage at the AC isolator because the inverter display is well under that when it cuts out.

6) The inverter does display the frequency @ 50Hz, backed up by my Megger from a socket.

I concur with your conclusion, but I need to check the voltage at the inverter with my meter rather than relying on the inverter display in order to definitively rule out a voltage drop issue.

Thanks again for taking the time.

 

[balbecdaze]

Nice idea Whinmoor. Bit of a long shot this but any of the viewers of this thread have a 4kW system near Bristol they wouldn't mind me taking temporarily out of commission? Have to be during a sunny day too.

Perhaps I'll be brave and call one of the local big boys to ask for a loan.

 

[balbecdaze]

Re: Any suggestions for Inverter woes? Minor update

Resurrecting this thread as I've finally managed to be at home on a day when:

a) there's enough cloud cover, lowish temperature for the inverter to run normally for a few hours.
b) I can predict(ish) when the sun is about to burn through the clouds enough for it to make my inverter cut out.

And, standing over the AC isolator with my meter, measuring the output voltage and it cuts out at 242V, Power output at that time was approx 2.6kW, frequency 50.0Hz for what it's worth. This confirms earlier readings from the inverter itself of happily within range voltage outputs when it cuts out.

Any other ideas and do I have to deal with the manufacturer or should my supplier take care of it if it is a warranty issue?

 

[Worcester]

As has been previously suggested, are you absolutely sure it's been set up for G83? (220V+10% = 242)
Ignore the stickers They can easily be wrong.
If the manual doesn't help, call your distributor and then the supplier to see if you can check in any way.

 

[balbecdaze]

As sure as I can be Worcester.

It's definitely output at 246V before, and it was fine on sunny days in winter. Really seems to be a combination of heat and light that does it. Been very frustrating these last few weeks ...

Take now for instance, irradiance at panels ~260W/m2, temp by inverter 26C, inverter in full shade because the sun's "gone round the corner", inverter (including heat sink) cool to touch ... nothing. I'd expect something at 6pm on a nice summers evening, <1kW, hardly pushing the specs of the inverter. The panels are in sunlight. And I'd turned off the AC and DC, waited 10 minutes then re-energised, just for fun.

I did call the supplier again today, got put on hold then promised a callback. Much like my inverter, nothing happened.

 

[Gavin A]

As sure as I can be Worcester.

It's definitely output at 246V before, and it was fine on sunny days in winter. Really seems to be a combination of heat and light that does it. Been very frustrating these last few weeks ...

Take now for instance, irradiance at panels ~260W/m2, temp by inverter 26C, inverter in full shade because the sun's "gone round the corner", inverter (including heat sink) cool to touch ... nothing. I'd expect something at 6pm on a nice summers evening, <1kW, hardly pushing the specs of the inverter. The panels are in sunlight. And I'd turned off the AC and DC, waited 10 minutes then re-energised, just for fun.

I did call the supplier again today, got put on hold then promised a callback. Much like my inverter, nothing happened.

IME all inverters we've used actually display 'G83' on screen at some point in the start up procedure for the inverter, so I'd really advise to switch the inverter off and on, then watch closely to ensure that it does actually display this in the start up procedure.

If not, then I'd say there's a good chance it's been set up wrong despite the sticker.

Another possibility if that the nominal grid voltage has been set wrong at 220V, which the inverter would use as a reference to set the maximum sustained voltage at +10% of that level.

For my money, those are the 2 most likely scenarios here, can't think of anything else it'd be to be honest.

 

[Gavin A]

eta - ah, other than the inverter being outside in full sunlight and overheating as a result. They shouldn't be put in full sunlight.

 

[balbecdaze]

eta - ah, other than the inverter being outside in full sunlight and overheating as a result. They shouldn't be put in full sunlight.

That, for my money, is what did it. It didn't specifically say G83 on startup, although it did say TL4000 GB, the GB standing for UK setup. As I say, its happily output at more than 242V on colder days.

So, after calling the supplier again yesterday, what arrives today?

A shiny new updated inverter.

Of course, that's probably the last of the sun for the year as well. :smiley2:

I've extended the overhang of the shade and installed it a little higher than the other one, its also wider and shorter than the old model, so that would help too. I'll keep an eye on the shading, I think I'm good at least apr-sept with the current setup.

Many thanks for all the helpful replies.

Its kinda kudos to the supplier, but then again they left me with the suggestion that they'd get in touch to arrange a replacement one month ago, so I've learnt the power of a bit of pestering too.