A large generator preventive maintenance schedule lists the checks and jobs done on the equipment at fixed intervals, how long each takes, and in what order of frequency, so problems are found before the large generator fails. This page gives the schedule used in the PlantOps360 task library for large generator (/ alternator with excitation system), which follows common industry practice for general-purpose equipment. It is also searched for as turbo generator, alternator, generator stator, excitation.
The maker’s manual and your site safety procedures always come first where they differ. Intervals set by law differ by state.
Large generator preventive maintenance schedule and checklist
| How often | Task | Estimated time |
|---|---|---|
| Daily | Record winding and bearing temperatures and vibration; check cooling air or hydrogen purity and pressure | 10 min |
| Weekly | Check slip rings and brushes (static excitation) and carbon dust; check space heaters | 20 min |
| Monthly | Check AVR operation and excitation current, cooling water flow and oil levels | 45 min |
| Quarterly | Insulation resistance and polarisation index of the stator winding when shut down | 90 min |
| Half-yearly | Check protection relays, neutral earthing and winding RTDs | 150 min |
| Annual | Annual overhaul inspection: rotor, stator wedges, bearings and coolers | 1440 min |
Large generator maintenance frequency and yearly workload
At the estimated times, one large generator needs about 122 hours of preventive maintenance a year. The biggest single job is “Annual overhaul inspection: rotor, stator wedges, bearings and coolers” at 1440 minutes, done annual. Multiply by the number of units you have to see the workload for your plant.
| Frequency | Tasks | Time per round | Hours per year |
|---|---|---|---|
| Daily | 1 | 10 min | 60.8 h |
| Weekly | 1 | 20 min | 17.3 h |
| Monthly | 1 | 45 min | 9.0 h |
| Quarterly | 1 | 90 min | 6.0 h |
| Half-yearly | 1 | 150 min | 5.0 h |
| Annual | 1 | 1440 min | 24.0 h |
What goes wrong on a large generator without preventive maintenance
- Winding insulation breakdown
- Bearing wear
- Brushes and slip ring wear
- AVR and excitation faults
What to watch between services
- Winding and bearing temperatures
- Vibration
- Excitation current and AVR operation
Safety and statutory notes for large generator maintenance
Insulation tests need isolation, earthing and discharge. Large machines carry protection that is tested on the schedule.
Where a large generator preventive maintenance schedule is used
This equipment is used in the industries below. Each link opens the preventive maintenance schedule guide for that industry, and the maintenance software page where we have one.
- Preventive maintenance schedule for chemical, fertiliser and petrochemical plants · maintenance software for chemical
- Preventive maintenance schedule for agro, grain, edible oil and sugar plants · maintenance software for sugar and distilleries
- Preventive maintenance schedule for steel, foundry, forging and metal plants · maintenance software for steel and metals
- Preventive maintenance schedule for cement, glass, ceramics and building materials plants · maintenance software for cement
- Preventive maintenance schedule for oil, gas and refinery facilities · maintenance software for oil and gas
- Preventive maintenance schedule for thermal and hydro power plants · maintenance software for power plants
- Preventive maintenance schedule for solar, wind and renewable energy plants · maintenance software for renewable energy
- Preventive maintenance schedule for water and wastewater utilities
Related equipment maintenance schedules
- Diesel generator set preventive maintenance schedule
- Gas engine generator set preventive maintenance schedule
- Gas turbine / turbo generator preventive maintenance schedule
- Wind turbine generator preventive maintenance schedule
- Hydro turbine, generator preventive maintenance schedule
- Battery energy storage system preventive maintenance schedule
- Solar tracker drives, controllers preventive maintenance schedule
Browse the full list of equipment preventive maintenance schedules (317 types).
Run this large generator schedule in maintenance software
In preventive maintenance software, each row above becomes a recurring task on the asset with its checklist, time estimate and parts. Tasks can be triggered by calendar date, running hours, meter readings or production cycles, each completed task is recorded with the person and date, and a failed check can open a work order. For the method behind it, read the guide to the preventive maintenance schedule, or use the free generator to get a 12-month plan for your whole equipment list.
Build my preventive maintenance schedule (free Excel)
Frequently asked questions
How often should a large generator be serviced?
In our schedule a large generator has 6 tasks: 1 daily, 1 weekly, 1 monthly, 1 quarterly, 1 half-yearly, 1 annual. The biggest job is “Annual overhaul inspection: rotor, stator wedges, bearings and coolers”, which is done annual. Always follow the maker’s manual where it gives a different interval.
What is included in large generator preventive maintenance?
It covers routine checks and jobs such as “Record winding and bearing temperatures and vibration; check cooling air or hydrogen…”, “Check slip rings and brushes (static excitation) and carbon dust; check space heaters”, “Check AVR operation and excitation current, cooling water flow and oil levels”, up to the annual overhaul or inspection. The full list with times is in the table above.
How many hours of maintenance does a large generator need per year?
About 122 hours per unit per year at the estimated times in our library, including the daily checks done every day. Use it to plan workload, not as a benchmark.
Is there a free large generator maintenance checklist?
Yes. The table on this page is a ready checklist. The free preventive maintenance schedule generator turns it into a 12-month Excel schedule for your list of equipment, with monthly workload hours.