Set the interval from the duty, not the calendar alone
Manufacturer intervals are a starting point. Running hours, starts, load level, dust, heat, humidity and altitude all change how fast a set wears. A standby unit that runs for a few hours a year ages through time and condensation; a prime power unit on a mine ages through hours and heat. The technician agrees the schedule with the owner and records the reason for it, so it can be adjusted when the duty changes.
What each level of visit covers
| Visit | Typical scope |
|---|---|
| Inspection | Visual checks, levels, leaks, battery and charger, alarms, short run |
| Minor service | Oil and filters, fuel water separators, belts and hoses, cooling system check, run under load |
| Major service | Minor service plus coolant renewal, valve and injector checks where due, alternator inspection, protection tests |
| Annual proving test | Extended load test, transfer switch test, full protection proving, report against previous year |
Trend the readings
The value of planned maintenance grows with every visit, because readings can be compared. Oil analysis that shows rising wear metals, coolant that is losing its protection or exhaust temperatures that creep up on one bank all point to a problem months before it stops the set. Larger plants can feed those readings into power station management software so trends are visible between visits.
Know when maintenance becomes refurbishment
At some point routine visits are no longer enough. High oil consumption, falling compression or repeated cooling problems suggest an overhaul. For larger engines and power stations USP&E also offers refurbishment of generating assets, planned around the plant so output is protected.
Preventive maintenance FAQs
How often should generator oil be changed?
Follow the running-hour interval for the engine and change at least once a year on standby sets, even if the hours are low, because oil degrades with time and condensation.
Is a weekly no-load run enough?
No. Short no-load runs can cause wet stacking and do not prove the set will carry load. Combine regular exercise with periodic load testing.
What records should a maintenance visit leave?
Readings, work done, parts used, defects found, recommendations ranked by risk and the next due date.
Plan your maintenance visits
Share your sets and their duty, and we will propose a schedule and a first visit.