Hedges
I See Electromagnetic Fields!
- Joined
- Mar 28, 2020
- Messages
- 20,694
We expect an MPPT to limit the current it draws to what it can handle.
Some have a diode which is normally reverse-biased, that will short out the PV string if hooked up backwards, to prevent damage. In that case there is a reason for maximum PV short-circuit current rating.
Some units have protection against over-voltage, while others would be killed. Some Midnight, for instance, say "Hyper-Voc", where they disconnect PV if somewhat over-voltage. That would have a limit to what it could handle.
Design your PV string so that even with the higher Voc that occurs during record cold temperature for your location, it will never exceed whatever maximum voltage is documented for the inverter/charge controller. If they document an over-voltage it can handle you can rely on that, otherwise whatever max voltage is given.
Some have a diode which is normally reverse-biased, that will short out the PV string if hooked up backwards, to prevent damage. In that case there is a reason for maximum PV short-circuit current rating.
Some units have protection against over-voltage, while others would be killed. Some Midnight, for instance, say "Hyper-Voc", where they disconnect PV if somewhat over-voltage. That would have a limit to what it could handle.
Design your PV string so that even with the higher Voc that occurs during record cold temperature for your location, it will never exceed whatever maximum voltage is documented for the inverter/charge controller. If they document an over-voltage it can handle you can rely on that, otherwise whatever max voltage is given.