The overspeed governor is a centrifugal mechanical device that continuously monitors the speed of the elevator car through the governor rope. When the car speed exceeds a preset threshold (typically 115% of rated speed), the governor mechanically grips the governor rope, which in turn activates the progressive safety gear beneath the car to arrest it on the guide rails. A second trip level (typically 140% of rated speed) may trigger the governor to cut power to the drive. The governor is a critical safety component tested during commissioning and periodic inspections.