Epever 40A tracer BN shows no voltage from PV

[Michael Roberts]

I've got four panels in series hooked up to an Epever BN series charger and the voltage is good until I actually connect them. I thought my full voltage would be fine according to my calculations, but it turns out the open-circuit voltage is 160V in full sunlight. I see a negligible voltage across the terminals when connected. Is that because the Epever is in overvoltage mode or something?

 

[Any name you wish]

Have you tried to connect just one panel to the system and see what happens? I wouldn't panel that system much past 130V with that controller.

 

[Michael Roberts]

I'll try that next. Or three, I guess, since that cable configuration will be easy to replug. I suppose a 2x2 series/parallel hookup would do the trick here.

 

[Michael Roberts]

OK, now I've got three panels in series hooked up to an Epever BN series charger and the voltage is 120V until I actually connect them. I see a negligible voltage across the terminals when connected, and an impressive spark (ahem) when I disconnect the cable without unplugging it first.

 

[Any name you wish]

Could also be related to system voltage as well. Here is the efficiency chart for that controller.

If you are running the 12V setup, you might be too high of voltage.

 

[Michael Roberts]

No, it's a 24V battery and the battery voltage on MT50 display reads correctly. I still don't see why I'd see 0.3V across the PV terminals on the Epever when connected, and there's nothing in the manual.

 

[Any name you wish]

If you see 120V then see .3V, that indicates a short circuit to me. Polarity correct? Meter in the correct mode for reading?

 

[Michael Roberts]

It sounds like a short circuit to me, too, except the wires aren't hot. The polarity is correct and the meter is in fact in DC mode. I guess it wouldn't hurt anything to try reversing the polarity just for laughs. The Epever has a diode in it. I'd still expect to see full voltage across the terminals if the polarity were reversed, though.

 

[Leeds]

Did you put 160v into a 150v charge controller?

If so it might be broken and this might just be how it acts now...

 

[Michael Roberts]

OK, I reversed the polarity. My multimeter now shows -93V under load and the Epever is perfectly happy and I have lost all mooring in reality.

 

[Michael Roberts]

Or my freakin colorblind self plugged the wrong leads into the wrong sockets on the freakin multimeter. Good God.

 

[Any name you wish]

Or my freakin colorblind self plugged the wrong leads into the wrong sockets on the freakin multimeter. Good God.

Ouch! Good luck on your electrical journeys.