[Simon O]

We have just had a 4kW system put in - ground mounted in the field adjacent to the house. It seemed to be working OK and producing readings on the meter in the house in line approximately with what I expected. On one of the rare occasions when we had sun I went out to look at the inverter which is attached to the side of the panel array and it showed a fault. When the sun was clouded over it seemed to be working OK but immediately the sun came out it showed a fault. I discussed with the installer who wondered if it was that our mains voltage was too high and he felt this was confirmed by the reading of approx. 256v on the inverter. However the energy company have been out and feel this is not a problem and within the tolerances that they have. At any rate the installing company are going to send someone out to look at it (though I am worried they'll come when it is cloudy and not see any problem). The installing company have been fine and seem to know what they are talking about in general terms, so I hope this is easily fixed. I assume the effect is to drastically reduce the amount the system will generate. Has anyone else had any similar type of problem or have any ideas about this?
Simon

[mab]

I have heard of this problem and it may be possible to adjust the software settings of the inverter to raise the voltage limit a bit.


How long is the cable from the inverter to the mains origin? and what size cable is it? If it is long / thin then there  could be enough voltage 'drop' over the length of the cable to cause problems whilst the voltage at the origin is still within spec - in which case a thicker cable could be your answer (or maybe running d.c. through the cable and putting the inverter at the other end of the cable).


If you do a search on the navitron forum (sorry dan) there are posts from people who have had this problem and hopefully their solutions:-


http://www.navitron.org.uk/forum/

[Sudanpan]

We did have some initial problems with our installation involving grid over and under voltage faults. We noticed it first because the faults combined with the PV installation would trip our barn fuseboard, which was a major pain in the proverbial. The circuit had been on a 30mA breaker so to start with we upped that to 100mA - but we still had issues.
We do have overhead electric supply and are relatively rural - we suffer from electric trip outs every so often and have had undervoltage issues before where the network providers warned all of us not to use electric motors etc while they were sorting the problems.
Our installers were always helpful and came out to see what was going on - they confirmed that the grid voltage was being quite erratic which was causing the PV system to lockout to protect itself. We then contacted Western Power and they confirmed that there were issues on the network which they would attend to. Since they did that work we have been ok wrt to the barn not tripping out - but the PV system will shut down and then restart when it needs to.

[Simon O]

Thanks for your info you guys that is helpful. There is a lot of info on that forum as you say mab, most going over my head, but is sounds like we ARE having a problem with too high a voltage at times ie when the sun comes out causing some type of surge. Hope it can get sorted out - the Solar panel engineer is coming out.
Simon

[Dan]

Our neighbour had exactly the same problem when they installed last year. It seemed to be very easy to fix, just needed the engineer to adjust some settings, so  for you. 

[Simon O]

Thanks Dan!