NEC Tables For Derating Conductors

	NEC Table 310-15(b)(2)(a)			NEC Table 310-15(b)(6) 120/240v 1Ph 3W
				Dwelling Service
	No. of Conductors	Derating Factor		Service or Feeder Rating	Copper	Alum. Or Copper-Clad
	4-6	80%		100	4	2
	7-9	70%		110	3	1
	10-20	50%		125	2	1/0
	21-30	45%		150	1	2/0
	31-40	40%		175	1/0	3/0
	41 +	35%		200	2/0	4/0
				225	3/0	250
				250	4/0	300
				300	250	350
				350	350	500
				400	400	600