Export Meter dropping KWh's

Dan59H · May 8, 2014

Apologies for the lack of detail not a PV installer,

Called to a job where the export meter was periodically going down. (Customer recorded it daily for about a month)
The finger was pointed at the export meter which was a Landis + Gyr.
Changed it for another Landis + Gyr and had a look at the Sunnyboy inverter, no error codes and readings seemed normal.
I advised the customer to continue monitoring it.

She has, for a week and reported that the same thing is continuing to happen.

Not sure if it is relevant but the panels at their height generated £200 and since have hovered around a fiver (might just be the gloomy weather though not sure).

I don't know whether to start blaming the inverter any Ideas would be much appreciated.

Earthstore · May 8, 2014

I believe you mean a generation meter, not an export meter.
What you do need to check is what the system is actually producing, my advice would be to get somebody that knows about pv to have a look, where in the country are you?
There may well be an installer on here that is local to the install.

Dan59H · May 8, 2014

Thanks for the advice I've e-mailed the manufacturers of the meter and the inverter but I wondered whether there might be a simple explanation that was common knowledge in PV circles.

Earthstore · May 8, 2014

Is it wired up the right way around, very common mistake on a generation meter?
What has happened to the install company?

Meggerman · May 8, 2014

Only time I have had a Landis Gyr digital meter fail, it lost display. You can prove that old meter with a plugtop, flex and a socket with than meter inbetween, then put the kettle on

. That meter is also registered against that install so FIT supplier needs to be informed, so put old one back if ok. Sounds like you have no output from inverter.

Dan59H · May 8, 2014

The supplier has been contacted re the new meter, and generally the meter is going up but it just occasionally starts shedding some of it's reading. the most it has gone down is 3kwh over a day, but generally less than one, and not all the time? I was tempted to blame the inverter as well.

Earthstore · May 8, 2014

This is just a thought, is there anything at all conected into the ac supply between meter and inverter, it has been known that people see it as an easy supply to add a socket or light into?

Meggerman · May 8, 2014

Earthstore said:
This is just a thought, is there anything at all conected into the ac supply between meter and inverter, it has been known that people see it as an easy supply to add a socket or light into?

That is an excellent point. If it was itmust be a reasonable current draw though, 3Kw/H plus any generation that day.

Gary K · May 9, 2014

Dan59H said:
Apologies for the lack of detail not a PV installer,

Called to a job where the export meter was periodically going down. (Customer recorded it daily for about a month)
The finger was pointed at the export meter which was a Landis + Gyr.
Changed it for another Landis + Gyr and had a look at the Sunnyboy inverter, no error codes and readings seemed normal.
I advised the customer to continue monitoring it.

She has, for a week and reported that the same thing is continuing to happen.

Not sure if it is relevant but the panels at their height generated £200 and since have hovered around a fiver (might just be the gloomy weather though not sure).

.

When you say it generated £200, I assume you mean it produced enough Kwh's to return £200 in FITS? Was this in a month? to do this I again assume they must be several years old and maybe on the original FIT rate of that is now about 49p. If it is now producing £5 in the same period, then there are real problems as thats about 1/3 Kwh per day and the weather hasn't been THAT bad.