I’ve read in other threads that you can ignore the 12A limit on the PV input so long as voltage is under 150. Is there really no limit at all on the Amp input?
I’m looking at 240 watt panels with 27.08 Voc and 10.71 Isc. If I run 4S2P I will be pushing 116.32 volts and 25 amps at 32 degrees Fahrenheit which is well within the voltage limit. Even accounting for the 12 amp limit and a worse case 149 degree Fahrenheit surface temperature, the panels will push 1300Watts giving me a longer max input time period. I was thinking the 25amps would make this configuration impossible.
Turns out I misunderstood basic rules of electricity. Amps will decrease in the cold and increase when the cell is hot. But still, 23A is almost twice the 12A limit
You don’t have to worry about max amps as long as your voltage is under the limit. Amps are just max, it is up to the device to pull them. Having more max amp will not damage the unit as it will not pull more than it can use.
Think of it this way, your 10W phone charger uses max 0.1A when charging. But you plug it into a wall socket that can supply 15A. It doesn’t destroy it because it just won’t use more than what it can.
Ah, thanks for the example case. That makes sense. Sounds like I can safely do a 4s2p array with 240 watt panels then. But I can save a little money going with 200 watt panels and still meet my 1200 watt goal at 149 degree surface temperature.
It is not. As long as your Voc is less than the maximum you are good. You’ll never get more than 1200W per input though as that’s how much the unit will accept. If you have the potential to supply more than 1200W, it doesn’t matter as that is just the potential. Again, think of the wall outlet and your phone charger, the wall outlet can provide 1500W but the phone charger only uses 10W, it doesn’t damage it because it expects 110V and will use what it can.
I have a system today that has 16kW of panels going into a 10kW max inverter.