Conductor Temperature Derating Calculator

How Conductor Temperature Derating works

The arithmetic follows ampacity = base × factor. Conductor Temperature Derating uses Base ampacity, Temperature factor to report Derated ampacity. Use Current-Limiting Impedance Calculator as the follow-up for required impedance.

With the loaded values, derated ampacity evaluates to 34.80 A. A second case makes the effect of one changed measurement visible.

Inputs for Conductor Temperature Derating

Base ampacity and Temperature factor belong to Conductor Temperature Derating. Keep source units with base ampacity.

Loaded numbers demonstrate the calculation; they are not equipment recommendations. Replace them with values from the case being evaluated.

Base ampacity

Example entry: 40 A.

Temperature factor

Example entry: 0.87.

Reading the Conductor Temperature Derating result

This output represents Conductor Temperature Derating.

The result informs selection but does not approve a component or installation.

Measurement and units

Treat these results as planning arithmetic; conductor and protective-device selection must follow the applicable electrical code and equipment instructions. Check prefixes on base ampacity.

Matching units and measurement locations prevent false differences.

Limits of this calculation

Use a factor for the actual insulation and ambient range. For required conductor area, use Wire Gauge Calculator.

The result reflects the formula scope, not every connected component. Unentered effects remain outside Conductor Temperature Derating.

Conductor Temperature Derating record notes

Record source and operating details for base ampacity. Cord loss belongs in the separate Extension Cord Power Loss worksheet.

Retain raw derated ampacity beside its selected rating.