The alternator converts the engine’s mechanical rotation into electrical power, producing the voltage and frequency your facility depends on. It also plays a major role in power quality when loads change, or when the system transfers during an outage.

• The Stator and Rotor: Massive copper windings where electromagnetic induction occurs, generating voltage through precisely controlled magnetic fields.

• The Exciter and AVR: The “brain” that maintains stable voltage under changing loads, ensuring your equipment receives consistent power regardless of demand fluctuations.

When alternator issues develop, the engine may still run while electrical output becomes unstable. Worn bearings, loose connections, contamination or winding damage can cause voltage drift, overheating, and nuisance alarms. In more severe cases, the generator may not carry load or may shut down to protect itself.

How often should it be inspected?

Alternators are evaluated for mechanical condition, clean connections, insulation health, and stable output every quarter during PM1 inspections—not just whether voltage shows on the screen. We verify voltage balance and check for rodent nesting.

Environmental Considerations: In coastal zones like Florida, we verify Strip Heater operation quarterly to prevent insulation rot from humidity. In dusty regions like Texas, we schedule more frequent “blow-outs” to remove dust buildup that creates dangerous thermal blankets around windings.

• Flickering Lights: Voltage instability as the alternator struggles to maintain consistent output under changing loads.
• High-Pitched Whining or Growling: Bearing failure creating audible noise that increases with load.
• Acrid Burning Smell: Melting varnish insulation on copper windings as temperatures exceed safe limits.
• Breakers Tripping Despite Low Load: Voltage spikes or imbalance causing protective devices to activate.
• Alternator Casing Hotter Than Engine Block: Excessive heat generation indicating internal electrical resistance or bearing friction.

“Can I pressure wash the alternator to clean it?”

Absolutely not. High-pressure water drives moisture deep into the windings, causing a dead short that destroys the alternator instantly. We use only low-pressure air and dielectric solvents specifically designed for electrical equipment. A $200 pressure washer can create a $50,000 alternator replacement.