Diesel generator sets – used for either prime or backup (emergency) power – must be regularly maintained to ensure they provide quality power throughout their service life. Larger companies who own many generators, or those who rely on gensets extensively for prime power, may require an in-house engineer to maintain their gensets. Smaller companies, or users who own a generator to provide backup power in the event of an outage, may establish maintenance contracts with generator dealers and/or electrical contractors to maintain their gensets. In either instance, the life-cycle of power generators is well established and documented making routine maintenance fairly straight-forward. Best generator maintenance practice is following the maintenance schedule provided by the manufacturer of the generator.