Why keep variable and fixed rework costs apart?

They move differently. Repair cost follows the failure count, while teardown, fixturing and retest charges stay put until the run size changes. Separating them shows whether to attack failures or the fixed setup burden.

Does the per-failure cost include the fixed charges?

Yes. It divides the whole rework bill, variable plus fixed, by the failed motor count. That is why it drops as the run grows: the fixed share spreads thinner with every additional failure.

What belongs in the teardown and fixturing charge?

Pulling the failed unit, opening the frame, setting up the repair fixture and preparing it for rework. Charge the fixture setup once per run, not per failed motor.

Should a repeated hipot failure cost the same as the first?

Often not. A second teardown and a second retest add labor, and repeated failures sometimes end in a rewind or scrap instead of a repair. Track second-pass units separately if they are common.

Motors, Generators & Electrification Equipment calculator

Rework From Failed Hipot Calculator

Total the cost of reworking motors that fail the hipot test. Enter the failed count, the repair cost each, and the fixed teardown, fixturing and retest charges the run carries.

What this calculator does

Hipot rework cost for a run of failed motors, split into variable repair and fixed teardown, fixturing and retest charges.

Formula used

Variable rework cost = failed motors × rework cost per failed motor
Fixed rework cost = teardown and fixturing + retest labor and overhead
Total hipot rework cost = variable rework cost + fixed rework cost
Rework cost per failed motor = total hipot rework cost ÷ failed motors

Inputs explained

Motors Failing Hipot: Units that failed the high potential insulation test this run.
Rework Cost per Failed Motor: Parts and labor to repair one failed motor, priced per unit.
Teardown and Fixturing Cost: Fixed teardown and fixturing charge for this rework run.
Retest Labor and Overhead: Fixed retest labor and overhead adder for the run.

How to use the result

Best suited to costing a hipot failure batch on one line, comparing repair and scrap for failed motors, setting a rework budget after a winding change.
Units that fail inspection twice or need a rewind cost more than one rework pass. Scrap values from unrecoverable units are not credited against the rework cost.

Current U.S. benchmarks

The producer price index for primary nonferrous metals (a broad metals benchmark, not copper alone) stands at 544.731 (BLS, Aug 2026), up 49.3% from a year earlier. Quotes priced off last quarter's material cost miss this move. Global copper trades at $13,543 per tonne (IMF via FRED, Jul 2026).
Steel mill PPI stands at 381.162 (BLS, Aug 2026), up 23.4% from a year earlier. New factory orders are up 8.5% year over year (Census).
The U.S. has 5,397 electrical equipment and appliances establishments employing about 369,437 workers (Census County Business Patterns, 2023).

Common questions

Why keep variable and fixed rework costs apart? They move differently. Repair cost follows the failure count, while teardown, fixturing and retest charges stay put until the run size changes. Separating them shows whether to attack failures or the fixed setup burden.
Does the per-failure cost include the fixed charges? Yes. It divides the whole rework bill, variable plus fixed, by the failed motor count. That is why it drops as the run grows: the fixed share spreads thinner with every additional failure.
What belongs in the teardown and fixturing charge? Pulling the failed unit, opening the frame, setting up the repair fixture and preparing it for rework. Charge the fixture setup once per run, not per failed motor.
Should a repeated hipot failure cost the same as the first? Often not. A second teardown and a second retest add labor, and repeated failures sometimes end in a rewind or scrap instead of a repair. Track second-pass units separately if they are common.

Last reviewed 2026-10-01.