How do you measure operating voltage of inverter?

I am looking at this inverter I am thinking of buying and its "MPPT Range @ Operating Voltage" is 120 - 450V.


I'm going to put 5 solar panels in series and they have an Open Circuit Voltage/VOC of 39.85 and the Umpp is 32.26 (look at screenshot)

How do I calculate the total voltage? Do I use the Open Circuit Voltage/VOC or the Umpp??

A friend of mine said that VOC and operating voltage are two different things.

Can anybody help? I'm a bit confused

Will the 5 solar panels in series work with this inverter??

Five of those panels in series would get you over the "minimum operating voltage" in full sun. Under shaded or cloudy conditions the voltage will drop below that minimum. It's an odd specification a minimum 120v. Put your five panels in series and see how it goes. Worst case is it doesn't charge when it's below 120v but I suspect it will still charge at lower voltages as long as it's more than the battery voltage. Maybe it has a programmed low PV voltage cutoff of 120 volts but that would strange since the spec also says max 8x36v panels in series. That tight of a voltage windows doesn't make sense.

Thanks for replying! Will the voltage drop if it's not full sun? I'm starting to doubt this inverter if it only will charge my batteries under certain conditions.

All charge controllers only charge under certain conditions. All PV systems drop current/voltage when fewer photons hit the panels. There are few differences in the way that MPPT charge controllers handle charging in less than full sun. So that itself is not disqualifying. I think the product listing contains errors so it is more difficult to determine what that unit can actually do.

What kind of errors are you thinking about?

From AlteStore: "
Open Circuit Voltage (Voc)
Open circuit voltage is how many volts the solar panel outputs with no load on it. If you just measure with a voltmeter across the plus and minus leads, you will read Voc. Since the solar panel isn’t connected to anything, there is no load on it, and it is producing no current.

This is a very important number, as it is the maximum voltage that the solar panel can produce under standard test conditions, so this is the number to use when determining how many solar panels you can wire in series going into your inverter or charge controller.

Voc will potentially be briefly produced in the morning when the sun first comes up and the panels are at their coolest, but the connected electronics haven’t woken up out of sleep mode yet.

Remember, fuses and breakers protect wires against over-current, not over-voltage. So, if you put too much voltage into most electronics, you will damage them."