AC Systems

208V Voltage DropCalculator

Calculate voltage drop for 208V three-phase commercial systems. NEC-compliant calculator for office buildings, retail, and light industrial applications.

AC Circuit Parameters

NEC Chapter 9 Table 9 values

Calculation Results

Pass
Voltage Drop
3.82V
1.83%
Voltage at Load
204.2V
of 208V source
Power Loss
144 W

Excellent - Meets NEC recommendations

208V Applications

  • Commercial office buildings
  • Retail facilities
  • Light industrial equipment
  • Commercial HVAC systems
  • Data closets and server rooms
  • Commercial kitchen equipment

AC Formula

Single Phase:
Vd = 2 × I × Z × L / 1000
Three Phase:
Vd = √3 × I × Z × L / 1000

Voltage Calculators

208V Voltage Drop Calculation Guide

About 208V Systems

208V AC systems are commonly used in industrial and commercial power distribution. Proper voltage drop calculations ensure equipment operates efficiently and safely within rated tolerances.

The NEC recommends limiting voltage drop to 3% for branch circuits and 5% total for the combination of feeder and branch circuit. For AC systems, this translates to a maximum drop of 6.2V for branch circuits.

Calculation Considerations

AC voltage drop calculations must account for both resistance and reactance of the conductors. The power factor of the load affects the effective impedance, making higher power factor loads more efficient from a voltage drop perspective.

For 208V systems, common wire sizes range from #14 AWG for lighting to #6 AWG for appliances. Always verify ampacity requirements alongside voltage drop calculations.