Hi There. What is wrong when the watts is low on one bank of panels but the volts is good. 

We have 48 panels of 265watt on the system. 4 x 5kva axpert 48v inverters. 12 panels per inverter. Now the problem we see is that 3 of the inverters gives good watts reading but one inverter gives low watts reading. The volts input from panels on all 4 inverters individual is around 126 volts.

For example the reading input on watts on 3 inverters is around 2100watt and 1 inverter is around 350 watt.

 

Please comment 

Regards David 

Maybe do a short icircuit test on each panel and compare te volts and amps to the spec sheet, you may have one bad panel in the string. Without current the volt will be fine same as open circuit voltage. And I guess all strings are facing in die same direction?