We are installing a circuit for some floresent lights in a wharehouse. The 12ga wire is run in conduit with a 20 amp breaker and at every light there will be a j box to wire into. The other guy is trying to tell me he wants to use 14ga mc from the j box to the light and tie it to the 12ga and the breaker won't have to be changed to a 15amp breaker because the whip is under 6feet from connection point to light. He claims its in the NEC allowing this. I don't know why he wants a 14ga wire here but I'm not thinking this is in the Nec. Is it or not