This installation is a perfect example of checking systems with failed inverters and not just simply installing a “same rated” inverter as the existing one.
Our customer in this case has 2 strings: 1 string of 5 panels facing north and 1 string of 5 panels facing east. They were connected to a 3Kw Macsolar inverter which had failed.
Upon doing a voltage measurement (which we always do) of both strings the DC volts were found to be very low ie: 172VDC (North string) and 127VDC (East string). This caused some issues with selecting an inverter which had what’s called “Dual Tracking” and which also had a low enough start up voltage to accommodate the low DC input voltages.
The Growatt 3000MTL-S fit the situation perfectly. With it’s dual tracking capability and low startup PV voltage at 70V it was the best choice for this installation. If the string voltages were higher there would have been many more options to chose from but as mentioned above, this is why it’s so important for us to do our due diligence and check systems before we make any offers.
Another benefit of using Growatt apart from their competitive pricing, is that for not much more money you can extend the warranty from 5 years to 10 years full manufacturer’s warranty. In the case of this inverter the extra cost was $220 to extend the warranty to 10 years. That’s affordable and provides peace of mind to customers knowing that their inverter won’t cost anything to replace for a decade.
If you have a solar system with a Macsolar inverter and it’s failed, ensure that whoever replaces it (hopefully us!) does their homework and fits a replacement that suits the DC voltage/s produced by your panels.
I hope this information is helpful.