Motor BC condutors

[wyatt]

A class question 1hp 115v motor 16FLC THHN
in my mike holt book says 14 awg is good by 310.16 table.
My instructor says has to be 12 awg that 14 is limited to 15 amp that table 310.16 is for derating only. Whos right?

 

[busman]

Re: Motor BC condutors

The single motor conductor ampacity it selected to be 125% of the FLC. The OCPD is selected based on table 430-152 (sorry I only have the '96 NEC today). So the answer is that the exception to table 310-16 is applicable and the 15 amp breaker limit does not apply.

Mark

 

[bphgravity]

Re: Motor BC condutors

240.4(D) only applies to circuits not listed in in part (G) of this section which specifically lists Article 430.

The #14 will be protected by a properly sized overload device which generally is sized at 115% of the motor nameplate.

 

[haskindm]

Re: Motor BC condutors

Tell your instructor to look for Tom Henry's Video on motors. Tom does a good job of explaining why the 15-amp restriction on #14 wire cannot be applied to motor circuits.