Systemy AC

AC Voltage DropCalculator

Profesjonalny kalkulator AC z wartościami NEC Tabela 9, współczynnikiem mocy i typami rur.

AC Circuit Parameters

Odniesienie NEC Tabela 9

Calculation Results

Pass
Spadek Napięcia
4.34V
0.90%
Napięcie Końcowe
475.7V
Line-to-line
Power Loss
720 W
Resistance
120.0 mΩ/kft
Reactance
44.0 mΩ/kft
Eff. Impedance
125.18 mΩ/kft

Excellent - Meets NEC recommendations for feeders

AC Voltage Drop Formula

Jednofazowy:
Vd = 2 × I × Z × L / 1000
Trójfazowy:
Vd = √3 × I × Z × L / 1000

Where Z (effective impedance):

Z = R×cos(φ) + XL×sin(φ)

NEC Chapter 9

Wartości impedancji AC pochodzą z NEC Rozdział 9 Tabela 9, uwzględniając efekty reaktancji w typach rur.

  • Steel conduit increases AC resistance due to magnetic effects
  • PVC/Aluminum conduit has no magnetic effect
  • Reactance becomes significant in larger conductors

Przewodnik po Współczynniku Mocy

  • Obciążenia rezystancyjne (grzanie): 1.0:1.0
  • Silniki: 0.80-0.90:0.80-0.90
  • Motors (starting):0.20-0.40
  • Oświetlenie LED: 0.90-0.98:0.90-0.95
  • Oświetlenie fluorescencyjne: 0.90-0.95:0.85-0.95

AC Voltage Drop Calculation Explained

AC vs DC Calculations

AC voltage drop calculations are more complex than DC because conductors exhibit both resistance and reactance (inductive impedance) when carrying alternating current. The effective impedance depends on the power factor of the load and the physical arrangement of the conductors.

Steel (magnetic) conduit increases the effective AC resistance compared to non-magnetic conduit like PVC or aluminum, particularly for larger conductors. This is due to eddy current losses in the conduit material.

Three-Phase Considerations

Three-phase systems use the √3 (1.732) multiplier instead of 2 used in single-phase calculations. This accounts for the phase relationships between conductors in a balanced three-phase system.

For unbalanced three-phase loads, calculations become more complex and may require analysis of each phase individually. This calculator assumes balanced loading conditions.