Maintenance and Care of Diesel Generators
Diesel generators are backup equipment that provides power when city electricity is unavailable. Regular maintenance can extend the lifespan of the generator. The maintenance of diesel generators is divided into weekly, monthly, and annual maintenance tasks.
Let’s learn the specific maintenance procedures for diesel generators.
Check the oil level. The oil level should be between the upper and lower marks on the dipstick. Add the same type of oil if necessary.
Check the diesel fuel level, drain sediment and water from the fuel tank, and check for leaks. The diesel fuel added should be allowed to settle for 24 hours.
Check the coolant level. The level should be about 5 cm below the radiator cap. Add distilled water if necessary.
Check if the coolant heater is working (check in winter).
Check the air filter indicator. If the red mark is visible, replace the filter element or the entire filter.
Check the battery charging voltage (for automatic units only). The normal charging voltage for a 12V battery is around 14V, and for a 24V battery is around 27V.
Clean the generator set.
The generator should run with a load for at least 30 minutes each month. The startup steps and inspection items are as follows:
Before Starting the Generator:
Check the weekly maintenance items, plus the following items:
Check the surrounding environment of the generator. The engine room should be well-lit, ventilated, and clean. Do not store any debris. Additionally, noise reduction measures should be adopted as per environmental requirements to ensure the generator runs normally.
Check if the intake and exhaust vents, as well as the exhaust pipe, are blocked.
General inspection: Check for any debris stuck in the radiator or engine, or if there are any loose or missing bolts or shields. Tighten or repair as necessary.
Check if the fan belt is too loose or worn. Adjust or replace if needed.
Inspect all instruments. All instruments should be intact, fully functional, and accurate. If damaged, replace or repair them.
Check the wiring of the generator and control panel to ensure there are no loose connections.
Check if the cooling water, lubricating oil, and diesel fuel are at the required levels.
Check for any signs of water, oil, air, or electrical leaks.
After Starting the Generator:
The generator should operate stably and run normally.
Check the oil pressure gauge: The normal working pressure is generally between 3~6.5 Bar. Small units typically have lower oil pressure values, while large units have slightly higher ones. Choose the appropriate oil viscosity based on regional and seasonal conditions.
Check the water temperature gauge: The water temperature should generally stay between 70~90°C, depending on environmental temperature and load size.
Check the charging voltage gauge: The charging voltage should generally be about 2-3V higher than the battery voltage.
Check the AC frequency.
Check the AC voltage.
Check the AC current.
Conduct a general inspection for abnormal sounds and leaks. Shut down the generator if necessary and perform repairs.
Check the cylinder operation, cooling water circulation, and exhaust color. If abnormalities are found, stop the generator for further inspection.
Shutting Down the Generator:
The generator can be shut down in two ways: normal shutdown and emergency shutdown.
Normal Shutdown: First, disconnect the load, and run the generator on no load for 5 minutes before turning it off.
Emergency Shutdown: If there are dangerous conditions or faults, shut down the generator immediately.
When the following situations occur, an emergency shutdown should be carried out:
(1) Over-speed fault.
(2) Oil line blockage or excessive water temperature (above 100°C).
(3) Unusual noise, loose flywheel, or faults in the drive mechanism.
(4) Sudden drop in the oil pressure gauge.
After Stopping the Generator:
Check the automatic switch (for automatic units) to ensure it is in the correct position.
Check the diesel fuel level, and refill if necessary.
Check for fault displays and arrange for repairs if needed.
Add lubricating oil to components outside the self-circulation system.
Keep a running record and clean the engine room and equipment.
Prepare for the next startup.
Check the weekly maintenance items, plus the following items:
Replace the fuel filter, and drain the fuel tank.
Clean the crankcase breather.
Check the valve clearance and adjust if necessary.
Inspect and test the engine protection system.
Check if the electrical ball is damp, clean the internal dust and debris, and use a megohmmeter to test and record the insulation of each winding. Grease the bearings.
Perform a load test by running the generator with at least 30% load for 2 hours and recording the data.
After the load test, replace the engine oil and oil filter.
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