The maintenance and upkeep of diesel generators, as the core equipment of backup or main power sources, directly affect the lifespan, operational stability, and emergency power supply capability of the equipment. We provide a systematic maintenance plan from five dimensions: daily inspection, regular maintenance, seasonal maintenance, long-term storage management, and fault handling
1、 Daily inspection and basic maintenance
Running status monitoring
Dashboard inspection: Before starting each day, observe whether the parameters of the voltmeter, ammeter, frequency meter, oil pressure gauge, water temperature gauge, etc. are within the normal range (such as oil pressure ≥ 0.3MPa, water temperature ≤ 95 ℃).
Abnormal noise/vibration: Listen for any abnormal noise from the engine during operation (such as knocking or bearing noise), touch the engine body to determine if the vibration is abnormal (industrial grade unit vibration value ≤ 7.1mm/s).
Exhaust color: Normal exhaust should be light gray, black smoke indicates insufficient combustion (check fuel injector or air filter), white smoke may indicate coolant leakage (check cylinder gasket or water jacket).
Fuel system maintenance
Fuel quality: Use 0-grade diesel that meets the GB 252 standard, avoiding water or impurities (water content ≤ 0.05%), and send the fuel quality for inspection every quarter.
Fuel filter: Replace the paper filter element every 250 hours of operation and clean the sediment at the bottom of the fuel tank every 500 hours.
Daily fuel tank management: Keep the fuel tank level between 1/2 and 3/4 to prevent air from entering the fuel pipeline due to low fuel level.
Lubrication system maintenance
Engine oil selection: Choose the appropriate viscosity based on the ambient temperature (such as 15W-40 suitable for -15 ℃~40 ℃ environment), and test the engine oil viscosity every 250 hours of operation (dynamic viscosity change rate ≤ 25%).
Oil change: Change the oil and filter every 500 hours of operation or 1 year (whichever comes first), and industrial grade units can extend it to 1000 hours (using fully synthetic oil).
Oil level check: Check the oil level before starting daily (it should be between the upper and lower marks on the dipstick). Low oil level can cause engine cylinder pulling.
2、 Regular deep maintenance (divided by operating time)
Maintenance every 250 hours of operation
Air filter: Clean the paper filter element (blow compressed air from the inside out, pressure ≤ 0.3MPa), and replace it if it is damaged.
Coolant inspection: Check the freezing point (≤ -35 ℃ in winter) and pH value (7.5~9.0), and use the same brand of coolant for replenishment.
Battery maintenance: Check the electrolyte level (10-15mm above the electrode plate), measure the specific gravity with a density meter (1.28 ± 0.01), and charge if the voltage is below 12.4V.
Maintenance every 500 hours of operation
Diesel filter: Replace the paper filter element and clean the impurities inside the filter seat.
Injector calibration: use the injector detector to test the injection pressure (the standard value varies depending on the model, such as 25.5MPa for Cummins NT855) and spray quality.
Belt tension adjustment: Use a tension meter to measure the tension of the generator belt (such as applying 50N force to the center point of a 12V belt, the deflection should be 10-15mm).
Maintenance every 1000 hours of operation
Valve clearance adjustment: Use a feeler gauge to check the intake valve clearance (usually 0.25-0.30mm) and exhaust valve clearance (0.35-0.40mm) in a cold state.
Turbocharger cleaning: Disassemble the turbocharger rotor, clean the bearings and oil seals with kerosene, and replace with specialized lubricating oil.
Oil pump inspection: Check the oil pump pressure (≥ 0.15MPa at idle speed, ≥ 0.35MPa at rated speed), and replace the pump body if the pressure is insufficient.
3、 Seasonal special maintenance
Winter maintenance (ambient temperature ≤ 5 ℃)
Coolant antifreeze: Replace with -35 ℃ antifreeze or use a mixture of "50% water+50% ethylene glycol".
Preheating system inspection: Test the intake preheating plug (resistance value should be 30-50 Ω) and coolant preheater (power ≥ 2kW) to ensure normal low-temperature start-up.
Fuel heating: Install electric heating belts on the daily fuel tank and fuel pipelines to prevent diesel from waxing (the condensation point should be 5-7 ℃ lower than the ambient temperature).
Summer maintenance (ambient temperature ≥ 30 ℃)
Heat dissipation enhancement: Clean the fins of the radiator (rinse from the front with a high-pressure water gun, pressure ≤ 0.5MPa), and remove surface willow fluff and dust.
Coolant circulation: Check the opening temperature of the thermostat (usually 82-88 ℃), and replace it if it is stuck.
Ventilation optimization: Ensure that the ventilation area of the computer room is equal to or greater than the heat dissipation capacity of the unit (1kW ≈ 0.3m ² ventilation area), and avoid hot air backflow.
Moist environment maintenance
Electrical system moisture-proof: Fill the control box with moisture-proof agent (such as silicone) and spray three proof paint (moisture-proof, anti mold, anti salt spray) on the motor winding.
Corrosion prevention of metal parts: Apply anti rust paint (such as epoxy zinc rich primer+polyurethane topcoat) to exposed metal parts such as unit casings and brackets.
4、 Long term storage management (inactive for ≥ 30 days)
Fuel system treatment
Drain fuel: Drain the diesel from the daily fuel tank and fuel pipeline to prevent gum deposition.
Add stabilizer: If fuel needs to be retained, add diesel stabilizer (such as Stanadyne Performance Formula) at a ratio of 1:1000.
Lubrication system protection
Replace long-lasting engine oil: Use fully synthetic engine oil containing anti-corrosion additives (such as Mobil Delvac 1 ESP 5W-40).
Turning operation: Manually turn 1-2 turns per week to prevent piston ring adhesion (the automated unit can set a timed turning program).
Battery maintenance
Disconnect: Remove the negative cable of the battery to prevent self discharge.
Regular charging: Use a smart charger to replenish power every 2 months (charging voltage 14.4V, charging time ≤ 8 hours).
5、 Common faults and emergency response
Startup failure
Troubleshooting steps:
Check the battery voltage (≥ 12.4V);
Test the starting motor (no-load current ≤ 200A);
Check if there is air entering the fuel pipeline (loosen the high-pressure fuel pump vent screw to exhaust);
Verify if the preheating system is working properly (30-60 seconds of preheating is required in winter).
Sudden shutdown during operation
Possible reasons:
Low oil pressure protection (oil pressure ≤ 0.15MPa);
Overspeed protection (speed ≥ 115% of rated speed);
The coolant temperature is too high (≥ 105 ℃);
The emergency stop button has been triggered.
Solution: Check the instrument alarm information, troubleshoot and reset the protection device.
Unstable output voltage
Adjustment method:
Check if the wiring of AVR (Automatic Voltage Regulator) is loose;
Measure the excitation current with a multimeter (rated value ± 10%);
Adjust the carbon brush pressure (0.15~0.25N/cm ²) and replace the worn carbon brush.