side of the disconnecting means for the motor control circuit.

VII. Motor Controllers

430.81 General. Part VII is intended to require suitable controllers for all motors.

(A) Stationary Motor of Vs Horsepower or Less. For a stationary motor rated at Vs hp or less that is normally

left running and is constructed so that it cannot be
damaged by overload or failure to start, such as clock
motors and the like, the branch-circuit disconnecting
means shall be permitted to serve as the controller.

(B) Portable Motor of xh Horsepower or Less. For a portable motor rated at xh hp or less, the controller shall

be permitted to be an attachment plug and receptacle.

430.82 Controller Design.

(A) Starting and Stopping. Each controller shall be ca- pable of starting and stopping the motor it controls and shall be capable of interrupting the locked-rotor current of the motor.

(B) Autotransformer. An autotransformer starter shall provide an "off" position, a running position, and at least one starting position. It shall be designed so that it cannot rest in the starting position or in any position that will render the overload device in the circuit inoperative.

(C) Rheostats. Rheostats shall be in compliance with the following:

(1) Motor-starting rheostats shall be designed so that the contact arm cannot be left on intermediate segments. The point or plate on which the arm rests when in the starting position shall have no electrical connection with the resistor.

(2) Motor-starting rheostats for dc motors operated from a constant voltage supply shall be equipped with automatic devices that will interrupt the supply before the speed of the motor has fallen to less than one-third its normal rate.

430.83 Ratings. The controller shall have a rating as specified in 430.83(A), unless otherwise permitted in

430.83(B) or (C), or as specified in (D), under the con- ditions specified.

(A) General.

(1) Horsepower Ratings. Controllers, other than inverse time circuit breakers and molded case switches, shall have horsepower ratings at the application voltage not lower than the horsepower rating of the motor.

(2) Circuit Breaker. A branch-circuit inverse time circuit breaker rated in amperes shall be permitted as a controller for all motors. Where this circuit breaker is also used for overload protection, it shall conform to the appropriate provisions of this article governing overload protection.

(3) Molded Case Switch. A molded case switch rated in amperes shall be permitted as a controller for all motors.

(B) Small Motors. Devices as specified in 430.81(A) and

(B) shall be permitted as a controller.

(C) Stationary Motors of 2 Horsepower or Less. For sta- tionary motors rated at 2 hp or less and 300 volts or less, the controller shall be permitted to be either of the following:

(1) A general-use switch having an ampere rating not less than twice the full-load current rating of the motor

On ac circuits, a general-use snap switch suitable only for use on ac (not general-use ac-dc snap switches) where the motor full-load current rating is not more than 80 percent of the ampere rating of the