Combiner box is turned off but I'm still getting a voltage reading

[Bowlegs868]

Recently I've noticed that even with the breakers in my solar array combiner box turned off, I still get a voltage reading on my digital multimeter

This can't be normal, right?

 

[Hedges]

Capacitors in SCC? They probably bleed down slowly.

To experiment, now that current is interrupted at the breakers, disconnect MC cables. That will really make it off (vs maybe slight leakage over surface of plastic in breaker due to humidity?)
I'd be nervous if switches/breakers maintained some conduction.

 

[Bowlegs868]

Capacitors in SCC? They probably bleed down slowly.

I guess you were right...

To experiment, now that current is interrupted at the breakers, disconnect MC cables. That will really make it off

so when I did this, the voltage I was reading turned out to be from the SCC... the voltage from the breakers were actually around 0.16

so thanks for pointing that out! ?? cheers ?

 

[Hedges]

So that was probably it.

Assuming no other "variables", like system running with AC or battery, which were turned off the next time you tried.
One guy got a shock from the PV connection of an inverter, even though PV hadn't been connected. It appears voltage leaked through and charged up the capacitors.
Yours at 3V is low enough to not worry about. But always check before touching, and if necessary disconnect other sources.
And check voltage to ground. Some systems have PV isolated, could be at a potential relative to ground. Some of mine drive the PV terminals during power-up to confirm they are isolated.

 

[Kornbread]

First time the pv breakers were truned off but voltage was still measured at the pv scc input, I was thinking ... what is going on? Then the voltage slowly dissipated. Next came the aha moment ... just like a capacitor.

 

[Bowlegs868]

So that was probably it.

Assuming no other "variables", like system running with AC or battery, which were turned off the next time you tried.
One guy got a shock from the PV connection of an inverter, even though PV hadn't been connected. It appears voltage leaked through and charged up the capacitors.
Yours at 3V is low enough to not worry about. But always check before touching, and if necessary disconnect other sources.
And check voltage to ground. Some systems have PV isolated, could be at a potential relative to ground. Some of mine drive the PV terminals during power-up to confirm they are isolated.

a lot of good info there... thanks! cheers! ?