Article 430 – Motors, Motor Circuits and Controllers
430.6 Conductor Ampacity and Motor Rating Determination.
(A) General Motor Applications.
(1) Table Values. Other than for motors built for low speeds (less than 1200 RPM) or high torques, and for multispeed motors, the values given in Table 430.247, Table 430.248, Table 430.249, and Table 430.250 shall be used instead of the actual current rating marked on the motor nameplate to determine the following:
(1) Ampacity of conductors
(2) Current ratings of switches
(3) Current ratings of branch-circuit short-circuit and ground-fault protection
Where a motor is marked in amperes, but not horsepower, the horsepower rating shall be assumed to be that corresponding to the value given in Table 430.247, Table 430.248, Table 430.249, and Table 430.250, interpolated if necessary.
Exception No. 1: Multispeed motors shall be in accordance with 430.22(B) and 430.52.
Exception No. 2: For equipment that employs a shaded-pole or permanent- split capacitor-type fan or blower motor that is marked with the motor type, and the marking on the equipment nameplate is not less than the current marked on the fan or blower motor nameplate, the full-load current marked on the nameplate of the appliance shall be used to determine the ampacity of branch-circuit conductors, in addition to the current ratings of the following:
(1) Disconnecting means
(2) Motor controllers
(3) Short-circuit and ground-fault protective devices
(4) Separate overload protective devices
Exception No. 3: For a listed motor-operated appliance that is marked with both motor horsepower and full-load current, the motor full-load current marked on the nameplate of the appliance shall be used instead of the horsepower rating on the appliance nameplate to determine the ampacity of branch-circuit conductors, in addition to the current ratings of the following:
(1) Disconnecting means
(2) Motor controllers
(3) Short-circuit and ground-fault protective devices
(4) Separate overload protective devices
(2) Nameplate Values. The motor nameplate current ratings shall be used to determine the values for the following:
(1) Separate motor overload protection
(2) For motors built for low speeds (less than 1200 RPM), high torques, canned pumps, or multispeed motors, the following:
a. Ampacity of conductors
b. Current ratings of switches
c. Current ratings of branch-circuit short-circuit and ground- fault protection
(3) Large motors exceeding the values in Part XIV shall use the nameplate current rating for conductor sizing.

Material taken from the National Electric Code. is reprinted with permission from NFPA 70., 2023 edition. National Electrical Code®, Copyright 2022, National Fire Protection Association, Quincy, MA. All rights reserved.