[HayZee518]

for electrical in a residence the electrical equivelant to copper wire size is one gauge higher. that is why I said 2/3 copper can be used but most of the time a 4/3 aluminum is used. it is cheaper and can safely handle 100 amps of current.
ok. here's a quote from the codebook:
MORE THAN THREE CURRENT CARRYING CONDUCTORS IN A RACEWAY OR CABLE. where the maximun number of current carrying conductors exceed three then the ampacities are reduced. - 4 to 6 -- 80%, 7 thru 9 --70%, 10 thru 20 --50%, 21 thru 30 --45%, 31 thru 40 -- 40%, 41 and above -- 35%. Notes: where cables or single conductors are stacked or bundled NOT in a cable assembly or in conduit, the above tables apply where the combined length is more than 24 inches.