 The governor is a safety measure that acts when the engine is approaching overspeed and will trip the engine off if the regulator governor fails.It trips off the engine by cutting off fuel injection by having the centrifugal force act on levers linked to the governor collar.Overspeed for power plant turbines can be catastrophic, resulting in failure due to the turbines' shafts and blades being off balance and potentially throwing their blades and other metal parts at very high speeds.