Power Electronics, Motors & Drives worked example

Drive Warranty Reserve at 92% expected warranty claim rate: a worked example

This scenario runs the drive warranty reserve calculation on the strong side: 92% expected warranty claim rate, with every other input held at its documented default. Use it when planning warranty exposure for VFDs, servo drives, traction inverters, DC-DC converters, or motor control electronics.

The inputs for this scenario

  • Drives in service under warranty: 100 drives (unchanged)
  • Expected warranty claim cost per drive: 45 $ / drive (unchanged)
  • Expected warranty claim rate: 92 % (raised for this scenario; the documented default is 80)
  • Fixed warranty program support cost: 250 $ (unchanged)

Working through the calculation

  • Applying the documented formula (Variable drive warranty reserve = drive population in service × expected warranty cost per drive × expected warranty occurrence) to the inputs above produces each figure below.
  • At this operating point the engine returns 4,390 $ for total drive warranty reserve, the number this scenario is built around.
  • At this operating point the engine returns 43.9 $ / piece for warranty reserve per shipped drive.
  • At this operating point the engine returns 4,140 $ for variable drive warranty reserve.
  • At this operating point the engine returns 250 $ for fixed warranty support cost.

How this compares with the baseline

  • Against the tool's baseline example, where expected warranty claim rate sits at 80% and the headline result is 3,850 $, this scenario comes in 14.03% above the baseline at 4,390 $.
  • Use it to set a warranty accrual, price an extended-warranty offer, or model the reserve impact of a suspected field issue. Treat this as a target state: the delta against the baseline quantifies what the improvement is worth before you commit to chasing it.

Results at a glance

  • Total drive warranty reserve: 4,390 $ (headline result)
  • Warranty reserve per shipped drive: 43.9 $ / piece
  • Variable drive warranty reserve: 4,140 $
  • Fixed warranty support cost: 250 $

Run it with your numbers

  • Every input above is editable in the live Drive Warranty Reserve calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.