I have a new 3.9kW 20 -195W panel system. My inverter reads PV output 84V in direct sun. I checked the control panel with a meter before & after fuses. 3 of 5 circuits ( 5 circuits , 4 panels each in series) reads ~84V in full sun. 2 of 5 are 0 V. I understand I need to troubleshoot each panel in the 0 V circuits as a panel(s) in each series may be bad. However, shouldn't the Voltage on the inverter be reading 84V+84V+84V or 252V? Is this an inaccurate calculation. Any other thoughts? Thanks
Four panels connected in series will give you about 84VDC in full sunshine with no load. If you connect these four panels in parallel to another set of four series connected panels, the overall output voltage will remain 84V. If you do that three more times, you'll have 5 sets of four series connected panels delivering 84 VDC to your inverter. I hope all of that makes sense :)
You will only measure 84VDC if the panels have no load on them. Once a load is added, this voltage will drop closer to 48VDC and this is totally normal. The load could simply be the batteries being charged by your system.
You don't mention what kind of inverter you have. But im guessing you have a 3500W/48VDC inverter. What is the display on your inverter showing?
Ron