Maintenance for alternator

2017-07-10

Structural Composition of the Alternator

A generator consists of a stator, rotor, end covers, frame, bearings and other components.
The stator is composed of the frame, stator core, coil windings, and other structural parts used to fix these assemblies.
The rotor comprises the rotor core (including magnetic yoke and pole windings), slip rings (also named collector rings), cooling fan, rotating shaft and other parts.
Bearings and end covers assemble and connect the stator and rotor together. The rotor rotates inside the stator to cut magnetic induction lines, generating induced electromotive force. The electromotive force is led out via terminal blocks and connected to a closed circuit to produce electric current.

Routine Maintenance

Based on daily inspection and upkeep, perform one round of routine maintenance every six months or one year:
  1. Conduct a full inspection of the unit’s water, electric, lubrication and air systems to confirm normal operating status;

  2. Run the unit under no‑load condition for 5–10 minutes for adequate lubrication; evaluate operating conditions through listening, visual observation and odor identification;

  3. Replace consumables including air filter, diesel filter, engine oil, oil filter, water filter and water‑oil separator element;

  4. Renew coolant and radiator conditioner for the cooling water tank;

  5. Supplement battery electrolyte or distilled water for storage batteries;

  6. Re‑inspect the whole unit after maintenance and complete overall cleaning work;

  7. Perform another 5–10 minutes of no‑load trial operation, and record all performance parameters of the unit.

Maintenance Scheme for Long‑running Generator Sets

(Applicable to construction sites, factories with frequent power outages, sites with overloaded transformers, project testing scenarios, locations without municipal power supply, and other scenarios requiring regular/continuous generator operation)

Level‑1 Technical Maintenance (50–80 operating hours, extra items on the basis of daily maintenance)

  1. Clean the air filter element and replace it when necessary;

  2. Replace diesel filter, air filter and water filter;

  3. Check the tension of transmission belts;

  4. Inject lubricant into all grease fittings and lubrication points;

  5. Replace cooling water.

Level‑2 Technical Maintenance (250–300 operating hours, extra items on the basis of daily & Level‑1 maintenance)

  1. Clean pistons, piston pins, cylinder liners, piston rings and connecting rod bearings, then inspect their wear conditions;

  2. Check whether looseness occurs on the inner and outer races of main rolling bearings;

  3. Remove limescale and sediment inside the cooling water passages;

  4. Clear carbon deposits in cylinder combustion chambers and intake/exhaust passages;

  5. Inspect wear matching of valves, valve seats, push rods and rocker arms, then complete lapping and adjustment;

  6. Remove carbon deposits on the turbocharger rotor, inspect wear of bearings and impellers; repair or replace defective components as required;

  7. Check generator‑diesel engine coupling bolts for looseness or thread stripping, and perform repair/replacement for faulty fasteners.

Level‑3 Technical Maintenance (500–1000 operating hours, extra items on the basis of daily, Level‑1 & Level‑2 maintenance)

  1. Inspect and adjust fuel injection advance angle;

  2. Clean the fuel tank;

  3. Clean the oil sump;

  4. Check the atomization performance of fuel injectors.



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