A variable frequency drive 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 variable frequency drive fails. This page gives the schedule used in the PlantOps360 task library for variable frequency drive (vfd / ac drive), which follows common industry practice for general-purpose equipment. It is also searched for as VFD, AC drive, inverter drive, frequency converter.
The maker’s manual and your site safety procedures always come first where they differ. Intervals set by law differ by state.
Variable frequency drive preventive maintenance schedule and checklist
| How often | Task | Estimated time |
|---|---|---|
| Daily | Check display for faults or alarms; check drive and motor temperature | 3 min |
| Weekly | Check cooling fan and panel ventilation; clean air filters | 10 min |
| Monthly | Check cabinet for dust, moisture and loose connections; check DC bus ripple if monitored | 20 min |
| Quarterly | Log parameters and compare with baseline; back up the parameter set | 30 min |
| Half-yearly | Tighten power and control terminals; thermography of terminations | 60 min |
| Annual | Replace cooling fans and filters as per OEM; check DC bus capacitor condition and earth connections | 120 min |
Variable frequency drive maintenance frequency and yearly workload
At the estimated times, one variable frequency drive needs about 37 hours of preventive maintenance a year. The biggest single job is “Replace cooling fans and filters as per OEM; check DC bus capacitor condition and earth connections” at 120 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 | 3 min | 18.3 h |
| Weekly | 1 | 10 min | 8.7 h |
| Monthly | 1 | 20 min | 4.0 h |
| Quarterly | 1 | 30 min | 2.0 h |
| Half-yearly | 1 | 60 min | 2.0 h |
| Annual | 1 | 120 min | 2.0 h |
What goes wrong on a variable frequency drive without preventive maintenance
- Cooling fan failure and heat build-up
- Dust on heat sinks
- DC bus capacitor ageing
- Loose power and control terminals
What to watch between services
- Heat-sink and ambient temperature
- Fault history in the drive
- Cabinet filters
Safety and statutory notes for variable frequency drive maintenance
Wait for the DC bus to discharge before opening a drive, and follow the maker’s procedure.
Where a variable frequency drive preventive maintenance schedule is used
A variable frequency drive is found in almost every industry. The industry guides below show how it fits into the wider schedule of each one:
- Preventive maintenance schedule for pharmaceutical plants
- Preventive maintenance schedule for food, dairy and beverage plants
- Preventive maintenance schedule for automotive plants
- Preventive maintenance schedule for chemical, fertiliser and petrochemical plants
- Preventive maintenance schedule for cement, glass, ceramics and building materials plants
- Preventive maintenance schedule for steel, foundry, forging and metal plants
- Preventive maintenance schedule for textile and garment mills
- Preventive maintenance schedule for thermal and hydro power plants
See all industry preventive maintenance schedules.
Related equipment maintenance schedules
- Electric motor preventive maintenance schedule
- High-tension motor preventive maintenance schedule
- Soft starter preventive maintenance schedule
- DC / servo motor and drive preventive maintenance schedule
- Industrial gearbox / speed reducer preventive maintenance schedule
- V-belt, chain and coupling drives preventive maintenance schedule
Browse the full list of equipment preventive maintenance schedules (317 types).
Run this variable frequency drive 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 variable frequency drive be serviced?
In our schedule a variable frequency drive has 6 tasks: 1 daily, 1 weekly, 1 monthly, 1 quarterly, 1 half-yearly, 1 annual. The biggest job is “Replace cooling fans and filters as per OEM; check DC bus capacitor condition and earth connections”, which is done annual. Always follow the maker’s manual where it gives a different interval.
What is included in variable frequency drive preventive maintenance?
It covers routine checks and jobs such as “Check display for faults or alarms; check drive and motor temperature”, “Check cooling fan and panel ventilation; clean air filters”, “Check cabinet for dust, moisture and loose connections; check DC bus ripple if monitored”, up to the annual overhaul or inspection. The full list with times is in the table above.
How many hours of maintenance does a variable frequency drive need per year?
About 37 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 variable frequency drive 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.