Case 53: Electrical faults can cause shaft and gear failures

摘要

When power disturbances occur such as grid switching or short circuits, motors or generators can experience a sudden speed variation due to unloading and loading. This event can cause a "braking inertia effect" on the machine system that can cause cracks in shaft keyways, coupling bolts or gear teeth. These may eventually become a fatigue failure due to normal loading. The model used here is for quick troubleshooting purposes on simple systems when a circuit is opened and quickly reclosed. It does not consider the electrical torsional vibration frequency torque.