How do you calculate hi-pot test capacity?

Multiply units per test cycle by available cycles, then apply uptime and pass rate. With 4 units/cycle over 480 cycles at 90% uptime and 97% pass rate, gross is 1,920 and good output is 1,676 units.

What is a good hi-pot first-pass pass rate?

Well-controlled coil lines run 97-99.5%. The 97% default is reasonable; consistent fails below that usually indicate insulation damage, moisture, insufficient impregnation, or an over-aggressive test voltage/ramp.

Why does uptime matter for a test bench?

Testers lose time to fixturing, calibration, operator breaks, and fault investigation. At 90% uptime the example loses 192 units of capacity — nearly a full extra hour of nameplate throughput gone to non-testing time.

Should failed units count against capacity?

For good, shippable output, yes. The 97% pass rate removes 51.8 units here. If you retest and recover most fails, model that as extra cycles rather than a higher first-pass rate.

How many units per cycle should I enter?

Enter how many units your fixture tests simultaneously. Single-station benches are 1; multi-position or gang fixtures may be 4 or more, which is why the default uses 4 units per cycle.

Hi-pot capacity vs impregnation batch size — how do they relate?

Impregnation feeds hi-pot. If both compute to 1,676 good units, they are balanced; if hi-pot is lower, add test capacity or a retest strategy so it does not starve shipping.

Transformers, Coils & Magnetics Manufacturing calculator

Hi-Pot Test Capacity Calculator

Hi-pot test capacity tells a magnetics manufacturer how many coils or transformers can clear dielectric withstand (hi-pot) testing good per period, after tester uptime and first-pass pass rate. Quality and manufacturing engineers use it because hi-pot is a mandatory 100% safety gate on most wound components — every unit must pass before it ships. If test throughput lags the winding and impregnation lines, finished goods pile up in front of the tester. This calculator separates the theoretical tester ceiling from the good, shippable count so you can staff and schedule the test bench to match production.

What this calculator does

Hi-pot test capacity tells a magnetics manufacturer how many coils or transformers can clear dielectric withstand (hi-pot) testing good per period, after tester uptime and first-pass pass rate.
Use it when hi-pot test capacity in transformers, coils and magnetics manufacturing is being asked to take on more work and you need to know if there is room.
It computes good units cleared through hi-pot testing from units per cycle, available cycles, tester uptime, and first-pass pass rate.

Formula used

Gross hi-pot test capacity capacity = units per cycle × available cycles
Good capacity = gross capacity × uptime × yield

Inputs explained

Units tested per hi-pot cycle:
Hi-pot test cycles available in the period:
Tester uptime:
Hi-pot first-pass yield:

How to use the result

Use it when balancing test capacity against upstream output, staffing the test bench, or deciding whether to add a second hi-pot station.
It treats failures as removed from the good count; it does not model retest loops, which can recover borderline units but consume additional cycles.

Current U.S. benchmarks

The producer price index for copper and brass mill shapes stands at 559.593 (BLS, May 2026), up 76.8% from a year earlier. Quotes priced off last quarter's material cost miss this move. Global copper trades at $13,484 per tonne (IMF via FRED, May 2026).
The U.S. has 5,397 electrical equipment and appliances establishments employing about 369,437 workers (Census County Business Patterns, 2023).

Common questions

How do you calculate hi-pot test capacity? Multiply units per test cycle by available cycles, then apply uptime and pass rate. With 4 units/cycle over 480 cycles at 90% uptime and 97% pass rate, gross is 1,920 and good output is 1,676 units.
What is a good hi-pot first-pass pass rate? Well-controlled coil lines run 97-99.5%. The 97% default is reasonable; consistent fails below that usually indicate insulation damage, moisture, insufficient impregnation, or an over-aggressive test voltage/ramp.
Why does uptime matter for a test bench? Testers lose time to fixturing, calibration, operator breaks, and fault investigation. At 90% uptime the example loses 192 units of capacity — nearly a full extra hour of nameplate throughput gone to non-testing time.
Should failed units count against capacity? For good, shippable output, yes. The 97% pass rate removes 51.8 units here. If you retest and recover most fails, model that as extra cycles rather than a higher first-pass rate.
How many units per cycle should I enter? Enter how many units your fixture tests simultaneously. Single-station benches are 1; multi-position or gang fixtures may be 4 or more, which is why the default uses 4 units per cycle.

Last reviewed 2026-05-12.