Makes sense to me! I can see when PWM specs have a spec panel limit, that is to keep the output amps from going too high. Most PWM brands are not self-limiting for amps. If you go over the amps rating the controller heats up and will eventually cook itself.
I now suspect but don't know, that the other MPPT controllers are more like the Midnite for how they really work except the Midnite specs are more clear about that? Folks who have them and have watched their monitors would know about that I guess. The other brands like MS must simply ballpark the array size as was suggested in replies above, so you can see what sort of array size "goes with" that controller but don't have to be exact.
It is confusing when the numbers don't come out right--makes me think I am missing something that might matter for my own MPPT set-up which has some over-panelling to it.
The critical Voc limit does mean you have to be exact and needs the numbers to come out right for cold temps too. So that is the real limiter on array size/arrangement with MPPT-- not the total wattage in the specs which are just broad brush numbers it seems.
