Governor - (1) A mechanical speed control mechanism. For elevator, it is a wire rope driven centrifugal device used to stop and hold the movement of its driving rope. This initiates the activation of the car safety device. It opens a switch, which cuts off power to the drive motor and brake if the car travels at a preset overspeed in the down direction. Some types of governors will also open the governor switch and cut off power to the drive motor and brake if the car overspeeds in the up direction. (2) On escalators, a direct-driven centrifugal device which, when activated by overspeed, cuts off power to the drive motor and service brake.
