Solar inverter over voltage reports.

gefnew

Hi just a thought you have changed an inverter lately is it set to g83 in the settings, i had similar grid over voltage when my system was installed the installer assumed that the inverter was set for the UK but came set to be German settings, got them to come and then reset it to g83.

JKenH

The inverter has been in 3 years 8 months. Two identical ones were fitted, one for each roof but so far I have only had the West roof switch off. It may be they are set to different thresholds but I haven’t had a look. I mentioned to the NPG engineer about adjusting the settings on the inverter but he suggested I wait and see what the investigation turns up. He mentioned they might fit a recording monitor to the transformer.

1961Nick

"Only 251.8v" is too close the the threshold of 253v & it's more than likely that your inverter is doing it's job & shutting down correctly. As mentioned before, they will move your supply to another tap on the transformer which is an easy job.

JKenH

Todays output, voltage and combined plots. I had quite a long outage this afternoon. Maximum voltage was 259.8v

JKenH

gefnew said:

Hi just a thought you have changed an inverter lately is it set to g83 in the settings, i had similar grid over voltage when my system was installed the installer assumed that the inverter was set for the UK but came set to be German settings, got them to come and then reset it to g83.

It looks as though it is set to G83.

1961Nick

Are both inverters showing a similar plot on the ac voltage Ken?

JKenH

1961Nick said:

Are both inverters showing a similar plot on the ac voltage Ken?

These are the two plots. 1 West roof and 2 East roof.

Power output for East roof. Only one outage.

1961Nick

Similar plots which confirms that the problem is more than likely to be the supply. Other than being 15v too high, the shape of the graph is what you would expect. 252v at sunrise eliminates solar as the cause.

Our mains voltage has been between 232v & 242v today (242v at sunrise).

JKenH

I forgot that my plug in energy meter shows voltage. It is quite variable and goes up and down with the sun but the house voltage is around 3v lower than what I am seeing at the inverters.

1961Nick

JKenH said:

I forgot that my plug in energy meter shows voltage. It is quite variable and goes up and down with the sun but the house voltage is around 3v lower than what I am seeing at the inverters.

That still puts the peak over 253v.

However, plug in energy monitors are typically accurate to +/- 3% & many of them only have a range upto 250v.