Over voltage protection - inverter tripped

Discovered from the app that we were not generating today, despite a lovely sunny day. Looking at the app, the generation ceased suddenly at around 12.30 ish.
It is an AC coupled system, and the Giveneregy side seemed OK, but the attic inverter was showing a fault status

• on investigation it had tripped out because of grid over voltage - the local grid had exceeded 255V at around 11.30am! I have it set up so I can interrogate that (Sofar) inverter separately from the givenergy unit, using the "solarman smart" app.
  UK grid limits are 216V to 253V, so it was out of limits locally, and I might need to tweak that OV setting, which I will do once I establish what password the installers left it with!

Just thought this might be of use to others.

wilfleek If you speak to your DNO they may be able to adjust the tap changer for your local Transformer to bring the voltage down. Although it'll do it for everyone so they will need to do some checks at some of the extremes of it's supplies to make sure this doesn't then cause under voltage to others.
As more and more PV installs enter the local grid this will become more of a problem for others.

What does the GE inverter show at that time (may need to view the old graphs on the old portal - don't think grid voltage has made it to the new one yet)

I found the voltage on the grid data on the inverter page of the beta portal.

I'll monitor the grid voltage for a while - 255V is actually out of tolerance limits - could have been a fault condition elsewhere on the system that caused a tap changer to get over excited.

I support a site that has monitoring on one of the incoming subs and it can tell via the meter which side of the meter the fault has been been detected. The wave form produced is fascinating. Records about 2 seconds of data at 1500hz. Nearly always it’s the board doing a tap change. But it can cause a big issue and result in loss of production.

hoggy BETA, Side menu, My inverter, Grid Data menu bar.

anabanet Oh good the graphs not all crunched up anymore! Didn't notice that. Cheers

@wilfleek Our voltage (which is normally on the high side anyway) jumped from mid 240s to 251 at the same time (which is bang on peak solar time) for about an hour then went back down again.
I do know the grid put the call out yesterday to get more generation available for the 4pm> peak as we were short, so there was a fair amount of the old coal plants just hovering around in readiness which won't have helped.

Same issue today - 256V just before 11am and the Sofar inverter is sulking again. Have called Western Power as this voltage is out of limits. To their credit, an engineer called within 30 minutes of my contacting them, and is now investigating at the local substation. Lol - he wouldn't take my Fluke DMM reading - pulled out his own battered no-brand DMM and confirmed what I had already told him!

Just to update - Western Power engineer has reset the local substation tappings to temporarily fix things, and then they are going to do the same thing further back in the network, on the HV side. have to say they were pretty good - engineer within 30 minutes of calling, and a courtesy call just now to tell me what they were going to do. 😃

And best of all - we are generating again!

That's the first good thing I've heard about Western Power in ages!

I've always found Western Power to be most helpful, they updated my supply fuse from 60A to 80A when I installed an EVSE. They repositioned my overhead supply when I needed to work on my roof. They guided me through my G99 application so as to facilitate an additional install of P.V. over and above what is normally accepted, (on the proviso they come and witness the operation of the grid limiting of my inverter). All this for no charge, I guess others might have had a different experience, but for me I really cant fault them.