Table

Duct Heater Line Current Multipliers

Duct Heater Line Current Multipliers lookup table with assumptions and boundary notes.

Scope

Multiplier planning only. Confirm heater nameplate voltage, phase, steps, and controls.

Lookup table

Use amps-per-kW multipliers for duct heater current estimates by voltage and phase.

Scroll sideways to keep row labels aligned with hidden columns.

Formula basis uses single-phase and balanced three-phase power equations for resistive heaters.
Voltage and phaseAmps per kWFormulaExample
120 V 1-phase8.331000 / 1205 kW x 8.33 = 41.7 A
208 V 1-phase4.811000 / 2085 kW x 4.81 = 24.0 A
240 V 1-phase4.171000 / 2405 kW x 4.17 = 20.8 A
600 V 3-phase0.961000 / (sqrt(3) x 600)30 kW x 0.96 = 28.9 A
Notes
  • Check table values for preliminary lookup and arithmetic checks only.
  • Confirm equipment ratings, product markings, installation conditions, utility requirements, and the local authority requirements before design or field use.