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jednofazowy • Prąd • Amps

Oblicz prąd dla jednofazowego

Prąd w amperach z mocy, napięcia i współczynnika mocy cos φ.

Wartości obliczeń

Uwaga: To obliczenie jest technicznie poprawnym uproszczeniem typowym dla kalkulatorów online. Przy doborze praktycznym trzeba również sprawdzić normy, sposób ułożenia, temperaturę, grupowanie, zabezpieczenia, typ kabla i dane producenta.

Zastosowany wzór

Dla instalacji jednofazowych:

I = P / (U × cos φ)

I is the current in amps, P the real power in watts, U the voltage in volts and cos φ the power factor.

Practical guidance

Understand current drawn by a 230 V load

Single-phase current is active power divided by voltage and power factor. The method suits one steady load.

Input values explained

Moc w watach
Use the electrical active power drawn by the load. A nameplate, data sheet or power meter is more reliable than an estimate.
Napięcie
Enter the voltage between line and neutral. This is commonly 230 V in low-voltage systems.
Moc factor cos φ
cos φ is the ratio of active to apparent power. It is close to 1 for resistive heating loads; use the data-sheet value for motors and transformers.

Example: 2,000 W heater

A mostly resistive heater takes 2,000 W at 230 V, so cos φ can be approximated as 1.

I = 2,000 W ÷ (230 V × 1) ≈ 8.70 A

Steady current is about 8.70 A. An electronic load of equal wattage can have a different current waveform and power factor.

Prefer the manufacturer's rated current

A nameplate current is normally more useful for actual design than a calculation from rounded power data.

Calculation limits

  • Cycling, inrush and nonsinusoidal current are excluded.
  • The result does not define cable size or breaker rating.