Query Fronius IG20

[OWLelectrical]

I dont profess to know much about solar but said I would check some voltages and ask on here for a friend. He has a Fronius IG20 inverter the panels are 180 ( unsure of make) thats what it says on paperwork. The inverter is saying that its only working at 50 %. He has 14 panels on 1 string. Does this sound right. When I tested the DC isolator there was 406v DC and the AC was 243v AC. Why is the efficiency down? Many thanks.

 

[Meggerman]

You need an irradiance meter and a DC clamp as well as voltage tester if you wish to measure performance accurately. However I can tell you this. The DC voltages rise quickly with irradiance but it is the current which is more greatly affected. The panels max rated performance Voc (Voltage Open Circuit) & Isc (Short Circuit) is based on standard test conditions of 1000w/m2, hence you need irradiance meter. Why do you think efficiency is down?

 

[OWLelectrical]

Thanks for the reply. He thought it was down as on the front of the screen the segment says it is only producing 45 % of the inverters maximum output surely this should be higher?

 

[Meggerman]

Tell him to look at it again in June on a clear day about 1.00pm when it is really sunny.