I have a Classic 150 Lite with a VFX3648 Outback inverter (see attach below)
According to the classic sizing tool, my system will go into hypervoc at -11. Its supposed to get down to -20 or so in a day or two. Should I just go ahead and shut the breakers off at the panel or will the Classic 150 Lite do that for me? Or can I sit there and watch the input voltage gauge on the local status app and go out there and shut it off if it looks like its going too high?
The voltage would be high when there is no load on the system like when the sun first is out or I think when the Classic is sweeping and you won't see that happen . That is when there is Voc ( open circuit voltage) . I am assuming you are talking about F temps and not C.
So to be safe turn your PV breaker off if it is going to be that cold at night . The other thing you could do if accessible and possible you could disconnect one pv panel from each series string and then you would be within the safe range ( if two pv in series would be high enough voltage to charge - run calculator with just two in series )
Larry
I waited till around 10:30 to turn the panels back on. I wasn't sure about the temp - my infared thermometer was all over the place and the weather app said -25, so I flipped it on and WOW it started pegging (current limit reached @ 70A). Almost 5kW in the last 1.5 hours.
Don't worry you can't hurt it, mine went down to -40°F went over hyper VOC. All it did was started clipping till I shut one breaker down then remedy the problem.