If you have a non working solar inverter and you’re looking at having it replaced, care must be taken to match the new inverter to your panel’s DC voltage/s.
It’s not as simple as just replacing your existing inverter with another of the same “Kw” rating. Mppt voltage ranges in inverters vary across the different brands and the only way to ensure you chose the correct replacement is to measure the DC voltage coming from your panels. Ideally, the voltage measurement should be done around midday to early afternoon on a nice sunny day so the panel voltage is at it’s maximum. Once this DC voltage has been ascertained, an inverter with an Mppt range to suit can be fitted.
If we look at a system with a Growatt 2000TL (2Kw) it has an Mppt voltage range of 120V-450V DC. If we compare that to a Fronius Galvo 2.0-1 (2Kw) which has an Mppt voltage range of 120V-335V DC you can see that there’s a significant difference. If your panels are producing a higher DC voltage than 335V it’s obvious that the Fronius Galvo will not suit your system – even though it’s the same “2Kw” rated size. On the flip side, just because your old inverter has a wide Mppt voltage range doesn’t necessarily mean it’s all being used. It may just have been what the designer chose based on price and/or availability.
Some inverters such as SMA’s Sunny Boy 1.5Kw and 2.5Kw have high Mppt voltage ranges in fact up to 160V – 500V DC. Other brands go even higher with their range even for the same “Kw” rating. So as you can see, not all inverters are equal even if their “Kw” rating is the same. Be careful when choosing a replacement inverter, do you due diligence and have the DC voltage measured to ensure your replacement inverter will suit your panels.
I hope this information has helped.