Maximum DC Input Current per MPPT
SpecificationThe highest direct current each MPPT channel can accept from the strings connected to it, in amperes. It limits how many strings may be paralleled on one tracker, since parallel strings add current while voltage stays the same.
Current, unlike voltage, is roughly proportional to irradiance and only weakly affected by temperature, so the design case is bright sunshine, sometimes with edge-of-cloud enhancement pushing briefly above standard test conditions. Add up the short-circuit current (Isc) of every parallel string on a channel and keep the total inside this limit with margin. Exceeding it does not usually destroy the inverter — most units simply limit and lose the surplus — but it means paying for modules whose output never arrives.