430 – Motors, Motor Circuits, and Controllers

430.2 – Electronically Protected (Motors)

Change at a Glance:

A new definition for “Electronically Protected (as applied to motors)” was added to 430.2.

430.2 Definitions. (Motors, Motor Circuits, and Controllers)

Electronically Protected (as applied to motors). A motor that is provided with electronic control that is an integral part of the motor and protects the motor against dangerous overheating due to failure of the electronic control, overload and failure to start.

430.122(B) – Adjustable-Speed Drive Motors

Change at a Glance:

Output conductors between power conversion equipment and a motor are generally required to have an ampacity equal to or larger than 125 percent of the motor full-load current.

430.122 Conductors- Minimum Size and Ampacity (Adjustable-Speed Drive Motors)

(B) Output Conductors. The conductors between the power conversion equipment and the motor shall have an ampacity equal to or larger than 125 percent of the motor full-load current as determined by 430.6(A) or (B).
Exception: If the power conversion equipment is listed and marked as “Suitable for Output Motor Conductor Protection,” the conductor between the power conversion equipment and the motor shall have an ampacity equal to or greater than the larger of:
(1) 125 percent of the motor full load current as determined by 430.6(A) or (B)
(2) The ampacity of the minimum conductor size marked on the power conversion equipment
Informational Note: The minimum ampacity required of output conductors is often different than that of the conductors supplying the power conversion equipment. See 430.130 and 430.131 for branch circuit protection requirements.

430.122(D) – Adjustable-Speed Drive Motors

Change at a Glance:

New requirement clarifies sizing of conductors for several motors or motor(s) and other load(s) that include adjustable-speed drive systems and power conversion equipment needs to be based on the rated input current to the power conversion equipment in the calculations (not HP rating of the motor on the output of the power conversion equipment).

430.122 Conductors- Minimum Size and Ampacity (Adjustable-Speed Drive Motors)

(A) Branch/Feeder Circuit Conductors.

(B) Output Conductors.

(C) Bypass Device.

(D) Several Motors or a Motor and Other Loads. Conductors supplying several motors or a motor and other loads, including power conversion equipment, shall have ampacity in accordance with 430.24, using the rated input current of the power conversion equipment for purposes of calculating ampacity.