Transformers, Coils & Magnetics Manufacturing worked example

Impregnation Batch Size at 65% vacuum and oven uptime: a worked example

This worked example runs the impregnation batch size numbers for a tougher week than the baseline: 65% vacuum and oven uptime instead of the typical 90%. Impregnation batch size tells a magnetics plant how many varnished or vacuum-pressure-impregnated (VPI) coils will actually leave the line good, given the fixtures per cycle, the number of cure cycles you can run, and real-world uptime and yield.

The inputs for this scenario

  • Coils loaded per impregnation cycle: 4 units / cycle (held at the documented default)
  • Impregnation cycles available in the period: 480 cycles (held at the documented default)
  • Vacuum/oven uptime: 65 % (the input this scenario stresses; the baseline uses 90)
  • First-pass impregnation yield: 97 % (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Gross impregnation batch size capacity = units per cycle × available cycles.
  • Good output capacity works out to 1,211 units at these inputs, and this is the headline figure for the scenario.
  • Gross capacity works out to 1,920 units at these inputs.
  • Uptime loss works out to 672 units at these inputs.
  • Yield loss works out to 37.44 units at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where vacuum and oven uptime sits at 90% and the headline result is 1,676 units, this scenario comes in 27.78% below the baseline at 1,211 units.
  • Use it when scheduling VPI or dip-and-bake ovens, sizing WIP between winding and impregnation, or checking whether the impregnation cell can meet a build plan. A result at this level usually justifies acting on the stressed input before touching anything else, because every other figure in the table is downstream of it.

Results at a glance

  • Good output capacity: 1,211 units (headline result)
  • Gross capacity: 1,920 units
  • Uptime loss: 672 units
  • Yield loss: 37.44 units

Run it with your numbers

  • To rerun this with your own numbers, open the live Impregnation Batch Size calculator, set vacuum and oven uptime to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.