MidNite Solar’s PV Transition Boxes & Combiners MidNite Solar offers a range of PV Combiners from our MNPV3 to the MNPV12v to the MNPV10-1000 volt to all our pre-wired combiners. This range of combiners accommodates PV systems as small as a two string off grid cabin up to 12 strings for a 50KW commercial grid tie inverter. 3.398 4.886 7.89 4.02 3.39 14.70 9.757 8.000 0.875 10.444 0.875 10.00 12.70 3.50 12.42 12.19 3.