Calculations for 480V 3-phase industrial systems. Commonly used in USA and Canada for heavy machinery and distribution.
Typical 0.8 - 0.9 for motors
Values for typical industrial 3-phase loads
| Power (kW) | Amps (PF 0.8) | Amps (PF 0.85) | Amps (PF 0.9) |
|---|---|---|---|
| 10 kW | 15.04 A | 14.15 A | 13.36 A |
| 20 kW | 30.07 A | 28.30 A | 26.73 A |
| 30 kW | 45.11 A | 42.45 A | 40.09 A |
| 40 kW | 60.14 A | 56.60 A | 53.46 A |
| 50 kW | 75.18 A | 70.75 A | 66.82 A |
| 75 kW | 112.76 A | 106.13 A | 100.23 A |
| 100 kW | 150.35 A | 141.51 A | 133.65 A |
| 150 kW | 225.53 A | 212.26 A | 200.47 A |
| 200 kW | 300.70 A | 283.01 A | 267.29 A |
| 250 kW | 375.88 A | 353.77 A | 334.11 A |
| 500 kW | 751.76 A | 707.54 A | 668.23 A |
Page intent
480 V is commonly encountered as a three-phase line-to-line value in industrial distribution. This page explains the assumption, the per-line result, and the equipment limits that sit outside the arithmetic.
For a balanced 50 kW load at 480 V L-L and PF 0.85, the current is 70.75 A per line. Raising voltage transfers the same kW with lower line current, but the insulation, clearances, switching category, and fault energy requirements become more demanding.
The calculator assumes a balanced three-phase load and a line-to-line input. A 480 V value measured line-to-neutral would require the L-N equation instead.
Industrial 480 V equipment may be connected line-to-line, line-to-neutral through a transformer or derived system, or through a delta/wye arrangement with no accessible neutral. Read the distribution one-line, equipment nameplate, and terminal diagram before entering a number.
A motor, heater bank, VFD, transformer, or server power supply can have very different PF and harmonic characteristics even at the same nominal voltage.
Treating the result as the breaker or cable ampacity ignores ambient temperature, conductor grouping, short-circuit rating, voltage drop, motor starting, and equipment SCCR. The line-current estimate is only one input into an industrial design review.
For this page, yes: the chart and calculator use balanced 480 V three-phase line-to-line input. Use L-N only when that is how the voltage is measured.
For the same real kW, phase arrangement, and PF, higher voltage produces lower current. The equipment still has voltage-specific insulation, switching, and fault requirements.
The balanced three-phase formula returns the approximate current in each line conductor, not a separate total to multiply by three.
No. Breaker selection also needs code, continuous duty, fault current, motor rules, ambient conditions, conductor ampacity, and equipment ratings.
