ECN Forum Forums Code Related Discussion NEC & other Code issues 110.14(C)(1)(a)(4)

Huh? Code change allows wires feeding certain motors to be running at the 75C current levels and yet be terminated in a 60C breaker?

I didn't read it that way. "if equipment is listed and identified for use with such conductors" appears several times in that article. I do agree it is not written well and you could make that deduction from the scrambled text out of context but I don't think that is the intent.

I agree with gfretwell, the original proposal 1999 was a modification to a exception adopted in 93. The proposal was directed towards the manufactures wiring of the motors, I take that to mean internal.
I believe the field wiring to the the motor would have to comply with the requirements of 110.14 (C) .

The 2005 change specifically was to delete reference to design E motors.

Yeah, gfretwell and cpal, I get the point that its ok to use the higher rated wire at the motor connections. Its just a bit confusing when they talk about both source and load end connections in the same section. The wording of 110.14(C)(1):
"(a) Termination provisions of equipment for circuits rated 100 amperes or less, or marked for 14 AWG through 1AWG, shall be used only for one of the following:
(1) Conductors rated 60*C (140*F).
.
.
(4) For motors marked..conductors having an insulation rating of 75*C (167*F)or higher shall be permitted to be used, provided the ampacity of such conductors does not exceed the 75*C (167*F) ampacity."

The 4th part leaves one to conclude that 75*C wire is ok to hook up to the 60*C breaker (or whatever overcurrent device is feeding the motor circuit). What would it hurt to change that last sentence to '..does not exceed the 60*C (157*F) ampacity.'?

PS, I'll be out of town for a couple of days, so I'll be glad to talk with you all some more about this at that time.

The only change in this cycle was the elimination of Design "E" motors.

Read in full context, (Equipment Provisions) it is only saying that motor terminal lugs are already suitable for 75C, since motors “in ordinary locations” are not listed. It isn’t saying anything about the breaker end.


[This message has been edited by rbalex (edited 02-04-2005).]