Solar inverter AC output current calculator

Preliminary estimate

Inputs

Calculation note

Use the inverter AC output current as a review screen only. Nameplate current and interconnection requirements still control the final design.

Method

kVA = inverter kW / power factor

A = kVA x 1000 / V

A = kVA x 1000 / (sqrt(3) x V)

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Formula variables

  • Inverter kW is the AC output power used for the estimate.
  • V is the selected nominal AC voltage.
  • Power factor adjusts real kW to apparent kVA.
  • Phase selects the single-phase or balanced three-phase current equation.

Assumptions

  • AC output current is calculated from inverter kW, nominal AC voltage, phase, and power factor.
  • The default assumes unity power factor for a simple nameplate-style estimate.
  • Actual nameplate current, continuous-output rating, utility interconnection rules, and inverter instructions can override the estimate.
  • This calculator does not size breakers, conductors, disconnects, protection, interconnection equipment, or PV installation requirements.

Examples

10 kW residential inverter. A 10 kW inverter at 240 V single-phase and PF 1.00 estimates about 41.7 A of AC output current.

50 kW commercial inverter. A 50 kW inverter at 600 V three-phase and PF 0.98 estimates about 49.1 A before nameplate and interconnection review.