How Often Should a DG Set Be Serviced?
Diesel generator service intervals are driven by two clocks — running hours on the meter, and calendar time regardless of hours. Whichever comes first wins. Here's the schedule Mecwel Engineers follows for Greaves DG sets across Assam.
The two-clock rule
If your DG set runs 8 hours a day, you'll hit 250 hours in about a month. If it runs only 20 hours a month for testing, you'll hit 250 hours in a year — but oil still degrades on the shelf and coolant still absorbs moisture. So service on the earlier of:
- Running hours milestone
- Calendar milestone (usually 6 or 12 months)
Standard service schedule
Every 250 hours or 6 months
Change engine oil, oil filter, fuel filter. Inspect belts, hoses, air filter. Check battery, coolant, all electricals. Load test at 80% for one hour.
Every 500 hours or 12 months
Everything in the 250-hour service, plus: change air filter, coolant test, injector inspection, alternator megger test, AVR calibration, earthing test.
Every 1,500–2,000 hours
Valve clearance re-adjustment, injector cleaning and calibration, governor inspection, alternator bearing check.
Every 8,000–10,000 hours (major overhaul)
Top-end overhaul or full overhaul depending on condition — cylinder head, piston rings, bearings, turbo.
What a proper PM visit looks like
A preventive maintenance visit shouldn't be a 20-minute oil change. Our engineers spend 2–3 hours on a typical mid-size DG set:
- Cold inspection and leak check
- Oil and filter replacement with genuine Greaves lubricants
- Coolant top-up and quality check
- Air, fuel and sedimenter filter replacement as per schedule
- Belt tension, hose inspection, radiator cleaning
- Battery test and terminal cleaning
- Control panel diagnostics — event log review, protection test
- Load run at 60–80% for 30–60 minutes, verifying voltage, frequency, temperature, oil pressure
- Written service report and next-due schedule
Do standby-only DG sets need service?
Yes — arguably more than heavily used ones. A generator that sits idle for months develops fuel algae, drained batteries, seized turbos and glazed cylinders. Every standby DG set should be test-run on load for 30–60 minutes every month and given a full service at least yearly.
Ready to power your business? Get a free quote from Mecwel Engineers — Guwahati's authorized Greaves Cotton dealer since 1991. Call +91 97060-11988 for on-site load survey and pricing across Assam.