ct clamps too close together?

[sean_ork]

I will try that when I get home. Is it ac off first then dc off? to turn on is it ac on then dc on?

Yes, those inverters do have inbuilt export limitation.

If you could confirm how the panels are configured (how many to each inverter) you should be able to get at least one working - don't forget the CTs are directional.

Again, has the system ever worked without faulting for any lengthy period of time ?

 

[jouleflow]

If each inverter has it's own individual AC isolator just turn two off, removing CTs will not do anything helpful.

Has this system ever worked for any extended period of time without faulting ?

Yes it has worked ok but never perfect, the bright weather could be affecting it as the inverters are being capped more than usual.

 

[sean_ork]

It would interesting to view the inverters log files, they should show what grid voltage the inverters are seeing - I suspect it's going above it's expected range.

 

[jouleflow]

If each inverter has it's own individual AC isolator just turn two off, removing CTs will not do anything helpful.

Has this system ever worked for any extended period of time without faulting ?

Yes it has worked ok but never perfect, the bright weather could be affecting it as the inverters are being

Yes, those inverters do have inbuilt export limitation.

If you could confirm how the panels are configured (how many to each inverter) you should be able to get at least one working - don't forget the CTs are directional.

Again, has the system ever worked without faulting for any lengthy period of time ?

I have double checked the cts & the arrow points towards the grid which is the direction of flow it is monitoring.

There are 54 260W panels and split into 18 panels per inverter.
They are all working at the moment, but still unsure if the 3 individual cts are affecting one another adversely.

 

[jouleflow]

It would interesting to view the inverters log files, they should show what grid voltage the inverters are seeing - I suspect it's going above it's expected range.

I did get the installer to make sure the voltage from the inverters was above the grid voltage to make sure it was used in preference to the grid. I don't know how to check the log files I'm afraid.

 

[sean_ork]

I did get the installer to make sure the voltage from the inverters was above the grid voltage to make sure it was used in preference to the grid. I don't know how to check the log files I'm afraid.

That's not quite how it works, but let's hope they've not altered any grid parameters.

You should quite easily be able to figure out how to access the statistics and logs, there's likely to be a Bluetooth connected app.

That'll likely be the second thing on the to do list of anyone you got to site.

 

[jouleflow]

That's not quite how it works, but let's hope they've not altered any grid parameters.

You should quite easily be able to figure out how to access the statistics and logs, there's likely to be a Bluetooth connected app.

That'll likely be the second thing on the to do list of anyone you got to site.

Thanks I will mention this check, I don't do apps etc and the only access I have to any data will be through the display & even then I may need a password to access some stuff.

I remember the output voltage was set to uk & when checked with a meter it was 260V. This was automatically set by the inverter when selecting uk.

 

[sean_ork]

If 260 was indeed your mains grid voltage, you'd probably be best advised to turn all inverters off, and get someone out to site.

That's way outside of the allowable range.

 

[jouleflow]

If 260 was indeed your mains grid voltage, you'd probably be best advised to turn all inverters off, and get someone out to site.

That's way outside of the allowable range.

Sorry Sean, the voltage that was measured was the output voltage from the inverter so automatically set to that when selecting uk. The mains incoming voltage was not checked as I recall at the time but when the subsequent new mains cable was installed by the dno it would have been checked then so should be around 240v.

 

[sean_ork]

Perhaps you've misunderstood what was done during the commissioning, at no point should there have been 260v measurable at the inverters output - the Country code is selected, and its that that defines the grid parameters.

A single, export limiting inverter, on a single phase, is a fairly conventional installation. Cascading, a number of inverters, on a single phase certainly isnt conventional, and given the apparent inability of the installer to correctly fit the CTs I very much doubt they'll have configured the export limiting correctly.

Given what you'll have already invested in your system, I really think you'd be best finding a Solis distributor or support and asking for a site visit - yours isn't a conventional installation so the average PV installer will have a lot of head scratching to do, you need to find someone who knows those inverters.

 

[jouleflow]

Thanks Sean, with so many variables to contend with & the most likely culprit being the "cascading" of the inverters. It is, as you suggest prudent to get a distributor in first to check. Now to find one that will. If I can't, my installer is accredited with -MCS - ELECSA - REEC & TSI. Should I contact one of those, which one is best suited to resolve the issue.

 

[jouleflow]

I have a Solis distributor calling in today. His diagnosis from my description is that one inverter could become a master controlled from a ct clamp. The other two will become slaves controlled from the master. This seems logical and prevents them all working independently. I hope it is possible & I haven't shortened the life of the inverters running them as installed since September.

I would assume that the remedy & subsequent work will be quoted for by the Solis distributor. What is the correct protocol for getting this settled by my initial installer, should I just get them to sort it out between themselves?

 

[Wilko]

Please let us know how it goes and if the proposed invertor control change affects the tripping behaviour of that separate RCD .

 

[jouleflow]

Please let us know how it goes and if the proposed invertor control change affects the tripping behaviour of that separate RCD .

no problem

 

[jouleflow]

The solar representative came yesterday & checked the system over. A really nice & knowledgeable chap. He pointed out a few odd jobs but the inverters not being linked was an issue. The latest Solis 4g inverters can't be linked intellegently to perform as one. He will get full details from a direct contact at Solis & a possible remedy. It was also noted that the position in the loft area was close to 36 degrees and has been hotter. They perhaps should have been mounted in the cooler garage area below. I will get a full report in a week or so & let you know.

Can I mention another point that could be affecting my system. Before the installation the earth was not too clever. As I mentioned before I am at the end of a line. When the solar was first installed they added an earth rod to see if it helped ( clutching at straws a bit ). Nothing changed and we had a new feed from the grid - 2 bigger wires. This must have helped the earth and I know that the neutral and earth wires are connected. So, if I have a small earth leakage & part of the path to earth goes via an earth rod. Would this present an imbalance and contribute to the rcd tripping. Should I disconnect the earth rods and just use the tested earth supplied by the dno?