when you have have more than 3ccc
's you must derate when in a pipe. If you don't know the insulation type "stripped nm cable" which column do you use to select the ampacity on 310.16?
if you have 10 conductors you would derate at 50%based on that you should be able to run #10 wire for an additional load in that same pipe of 20 amps with a derating factor of 50%
NM that is protected by a raceway is require to have the outer jacket enter the box or cabnet at least 1/4" 314.17(B) or (C) The "2005" make's it a little clearer