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Motor conductors and OCPD.

2K views 12 replies 5 participants last post by  micromind 
Cow has it right.

430.6 (A) (1) states that table values are to be used for wire and breaker size. 430.6 (a) (2) states that nameplate values are to be used for overloads.

110.14 (C) (1) (a) (4) states that the 75º column is to be used for motors.

240.4 (D) and Table 240.4 (G) remove the 15, 20 and 30 amp restrictions for #14, 12 and 10s. The actual values in Table 310.16 apply.

Table 430.52 allows a breaker to be sized up to 250% of the table value.

One of the funniest cases allows #14s to be used with a 40 amp breaker serving a 1HP 1ø motor operating on 115 volts.
 
Also, the red reset button qualifies as a the overload protective device. The only other protection you need is short-circuit and ground-fault. The breaker in the panel qualifies, and in your case, provided it is not over 70 amp.

If it were me, I'd use a 50 and either #8s or #10s.
 
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