Common Faults, Causes and Solutions of Diesel Generator Sets

I. Failure to Start

1. Insufficient battery voltage, oxidized and loose wiring terminals, weak starting motor.

   Solution: Clean the terminals, charge or replace the storage battery.
2. Air trapped in fuel pipeline, water contained in diesel fuel, excessive accumulated water in water-oil separator, resulting in fuel supply interruption.

   Solution: Drain accumulated water, bleed air from fuel pipeline, replace diesel filter.
3. Severe blockage of air filter, insufficient air intake.

   Solution: Blow clean or replace the air cleaner.

II. Unstable Generator Voltage with Fluctuating Readings

1. Damaged or unstable AVR (Automatic Voltage Regulator); worn carbon brushes causing poor contact.
2. Fluctuating load and loose circuit wiring terminals.
3. Fluctuating engine rotating speed.

III. Abnormal Exhaust Smoke

1. Black smoke: Overloaded unit, clogged air filter, poor atomization of fuel injectors.

   Solution: Reduce electrical load, clean air filter, calibrate fuel injectors.
2. Blue smoke: Engine oil enters cylinders for combustion, excessive engine oil level or worn piston rings.

   Solution: Drain excess engine oil and carry out major engine overhaul.
3. White smoke: Water mixed in diesel fuel, excessively low water temperature or water seepage from cylinder head gasket.

   Solution: Replace with qualified diesel fuel, fully preheat the unit, and inspect cylinder head gasket.

IV. Excessively High Water Temperature & High Temperature Alarm

1. Radiator blocked by dust, catkins and debris, leading to poor heat dissipation.
2. Insufficient coolant/antifreeze or faulty thermostat.
3. Long-term overloaded operation.

V. Low Engine Oil Pressure Alarm

1. Insufficient engine oil volume, deteriorated engine oil that has not been replaced for a long time.
2. Clogged oil filter or insufficient pressure output from oil pump.

VI. Excessive Vibration & Loud Noise During Operation

1. Aged and damaged vibration-damping rubber pads at the base.
2. Loose anchor bolts and unbalanced stress on four engine support feet.
3. Excessive coaxiality deviation between alternator and diesel engine.

VII. Automatic Shutdown (Engine Stalls Mid-operation)

1. Depleted fuel or blocked fuel pipeline.
2. Activation of over-temperature / low oil pressure protection, triggering automatic shutdown via controller.
3. Malfunction of sensors.

VIII. Electric Leakage & Circuit Breaker Tripping Power Cut

1. Damp wiring, aged and damaged cables; damp alternator winding coils.
2. Short circuit or overload of electrical equipment.