I am adding a mini split from the sub panel of my home to additional room I am adding . Mini split of 120 v, 9000 btu and 20 Ampacity. From panel to disconnect fuse box,my contractor installed 8/3 ( 8 gauge??) wire but mini split require 20 amp ( 20 ampacity) which should be Ok with 12 or 10 gauge wire. Is it ok to connect the this mini split with this 8 gauge wire to pass Vito inspection ? Wire length may be 20 ft.