In Alternator Overspeed Due to?

Overspeed: The chief cause of overspeed is the sudden loss of all or the major part of load on the alternator. Modern alternators are usually provided with mechanical centrifugal devices mounted on their driving shafts to trip the main valve of the prime-mover when a dangerous overspeed occurs.

What are the faults occur in alternator?

Some of the Important Faults which may occur on Alternator are Overvoltage, Overspeed, Overcurrent, Failure of Prime mover, Unbalanced Loading, Failure of Field and Stator winding fault (which includes Line to Ground Fault, Line to Line Fault, Double Line to Ground Fault, Three phase Fault and Inter turn Fault.)

What is alternator speed?

Typically, alternators have their full output rated at 6000 RPM but can continue to spin up to 12,000 RPM or more without any additional increase in output. The speed of an alternator is different for different type of car. The speed of an alternator depends on the speed of the engine.