A diesel generator set only performs as well as the maintenance routine behind it. This checklist is written for plant engineers, distributors and project contractors who need a defensible, documentable maintenance plan for Cummins, Perkins, Volvo, MTU, Weichai, Yuchai and Shangchai powered generator sets.
Why a written checklist matters
Most premature generator failures are not manufacturing defects. They come from missed service intervals, contaminated fuel, loose electrical connections and neglected cooling systems. A written checklist turns maintenance from "someone remembers" into a repeatable, auditable process.
- It protects the warranty position with the engine manufacturer.
- It gives the site team an objective record for insurance and audits.
- It shortens fault-finding, because deviations show up as trends.
Daily checks (before every start)
| Check | What to look for | Action if abnormal |
|---|---|---|
| Fuel level and water trap | Water or sediment in the pre-filter | Drain and record |
| Lube oil level | Between min and max on the dipstick | Top up with the specified grade |
| Coolant level | Within the expansion tank window | Top up with correct inhibitor mix |
| Battery voltage | 24V systems: above 25.2V at rest | Charge or replace |
| Leaks | Oil, fuel or coolant under the baseframe | Isolate and repair before running |
| Alarm panel | Active pre-alarms or shutdown codes | Clear the fault before starting |
Monthly checks
- Run the set on load for at least 30 minutes — a no-load run does not burn off condensation.
- Inspect the air filter restriction indicator and clean or replace the element as required.
- Check belt tension and look for glazing or cracking.
- Test the battery charger output and clean terminal corrosion.
- Verify the ATS transfer and retransfer sequence with the site electrician.
- Record exhaust gas colour and any change in noise signature.
Annual service items
- Replace engine oil and oil filter regardless of running hours.
- Replace the fuel filter and water separator elements.
- Check and adjust valve clearances to the engine manufacturer's specification.
- Flush and renew the coolant if the inhibitor concentration has dropped out of range.
- Load-bank test the set to confirm it delivers rated power at the site voltage and frequency.
- Torque-check the main power connections and inspect cable terminations for heat damage.
- Function-test all safeties: low oil pressure, high coolant temperature, overspeed and emergency stop.
Spare parts worth shipping with the order
Buyers in remote locations should confirm the following are included in the container:
- Full set of filters (oil, fuel, air, water separator)
- Coolant and oil in the correct specification
- Belt set
- Controller and AVR spares where the site is far from service support
- Fuses, relays and a printed wiring diagram
Records to keep
Keep a single logbook per generator. Every entry should carry the date, running hours, the work performed, the parts used and the name of the technician. This log is the first thing an engine manufacturer's service network will ask for when a warranty claim is raised.
Talk to the factory before you set the interval
Service intervals depend on duty, fuel quality, ambient temperature and dust load. For standby sets running a few hours a month, an annual service is usually adequate. For prime-power or continuous duty in dusty environments, the interval may need to be halved.
If you are specifying a new set or standardising maintenance across a fleet, request a quotation or technical confirmation and our engineering team will help you build the interval table for your site conditions.