The fan and fan drive move air through the radiator to remove heat from the coolant. In a stationary generator that airflow is critical because cooling depends on consistent fan performance during a run. When the fan drive has problems, airflow drops and temperatures rise quickly even if coolant level is correct.

• Forced Air Cooling: The fan pulls ambient air through radiator fins removing heat from coolant and maintaining proper engine operating temperature under all load conditions.

• Belt Drive System: Fan drive belts transfer power from engine crankshaft to fan maintaining proper speed ratio for adequate airflow without excessive noise or vibration.

Worn belts, damaged blades, or loose hubs can also create vibration that stresses the radiator and shroud. Overheating often appears under load or during longer run times.

How often should it be inspected?

Fan systems are inspected for belt condition, blade integrity, alignment, tension, and airflow effectiveness every quarter during PM1 inspections—not just whether the fan is spinning.

Environmental Considerations: Fans in dusty environments accumulate debris on blades reducing airflow efficiency. Coastal environments cause corrosion of fan hubs and mounting hardware. Generators in hot climates require more frequent fan system inspection as thermal stress accelerates belt degradation.

• Overheating Under Load: Engine temperature rises above normal during loaded operation indicating insufficient airflow through radiator.
• Squealing or Chirping from Belt: High pitched noise from fan belt area indicating glazing, misalignment or improper tension.
• Visible Belt Cracking: Cracks across belt surface revealing age-related deterioration and impending failure.
• Fan Blade Damage: Bent, cracked or missing pieces of fan blades creating vibration and reduced airflow.
• Excessive Vibration: Noticeable shaking during operation suggesting fan imbalance or loose mounting hardware.

“The fan is spinning—does that mean the cooling system is working properly?”

Not necessarily. A spinning fan can still provide inadequate airflow due to worn belts slipping under load, damaged or missing blade sections, or incorrect belt tension. Even minor belt slippage reduces fan RPM significantly cutting airflow when you need it most under heavy load. Damaged fan blades create turbulence instead of smooth airflow through radiator. We measure actual belt tension and inspect blade condition during PM1 because visual confirmation of fan rotation tells you nothing about airflow effectiveness. Generators that run fine during no-load testing often overheat during actual power outages when inadequate fan performance is exposed under sustained load.