DC voltage from series PV array to inverter is 0

[dave82]

I noticed that my inverter is not getting any input DC voltage. The voltage between DC+ and DC- initially is 4V and keeps going down to almost negligible.

went up on the roof and checked the junction box and found the same readings.

I am trying to understand where the problem is and have the following questions.

I have 10 modules (panels) in series with each giving 35 V, and hence the ideal DC voltage should have been 350V.

1. What happens if one of the modules is dead. Would that mean 0 DC voltage ?
2. What happens if there is an open connector. Let’s assume negative of panel 4 and positive if panel 5 connection is loose, and creating an open circuit. ? Would that lead to 0 DC voltage ?

 

[Bud Martin]

It looks like you made two duplicate threads.

DC voltage from PV array is almost 0

I noticed that my inverter is not getting any input DC voltage. The voltage between DC+ and DC- initially is 4V and keeps going down to almost negligible. went up on the roof and checked the junction box and found the same readings. I am trying to understand where the problem is and have the...

diysolarforum.com

 

[2milehi]

It sounds like there is an open circuit with your wired-in-series panels. This can be cause by a bad connection between the panels. You'll have access the panels and measure voltage from the "negative" end of the series circuit to the middle of the circuit (5th panel from negative). If you have ~170 volts, then the short is between panel 5 and the "positive" end of the series circuit. Then split it up until you find the open.

Use caution when measuring voltage with your DMM.