Inputs

Calculation note

This estimates I squared R loss from entered current and resistance. Voltage drop, ampacity, conductor temperature, and product limits remain separate.

Method

Loss watts = current squared x resistance x current-carrying conductors

Loss kW = loss watts / 1000

Energy kWh = loss kW x operating hours

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Formula variables

  • Current is the load current in amps.
  • Resistance is the entered conductor resistance in ohms.
  • Current-carrying conductors scales the loss estimate.
  • Operating hours converts power loss into energy.

Assumptions

  • Resistance is entered for the conductor path being evaluated.
  • Current-carrying conductors are entered by the user for the loss estimate.
  • The result does not model changing current, conductor temperature feedback, or enclosure heat transfer.
  • This calculator does not replace voltage-drop or ampacity review, thermal analysis, or product temperature limits.

Examples

Feeder loss screen. 80 A through 0.05 ohm across three current-carrying conductors estimates 960 W and 7.68 kWh over 8 hours.

Review workflow. Use voltage drop, conductor resistance, and operating profile checks before treating losses as final.