Is it allowed to nun type use-2 or rhh or rhw-2, 4 conductor, #2 #2 #2(neutral) #4 (equp. grd.)(conductors without outer covering)out of 200amp. main panel in basement,across bottom of joists up stairs into attic and down into 100AMP. sub.(NOT IN CONDUIT) QUESTION: DOES IT have to be run in coduit---conduit where it enters panel.QUESTION:HAVE TO BE IN CONDUIT AFTER IT GETS UNDER A TRAILOR.