How Many Watts Is 850 Amps at 480V?
A 850-amp circuit at 480V delivers 600,675.22 watts across three line conductors at PF 0.85. Real-world AC loads with lower power factor deliver less real power per amp.
At 600,675.22W, this is equivalent to 600.68 kW. NEC 210.19(A) sizes the conductor and OCP at 125% of any continuous load (equivalently 80% of breaker rating), so the usable continuous capacity on this circuit is about 480,540.18W.
For comparison at the same inputs: 408,000W on DC, 346,800W on AC single-phase at PF 0.85. These are reference values for contrast; the canonical answer for this page is the one in the hero above.
Use this citation when referencing this page.
Assumes an AC three-phase L-L circuit at PF 0.85. Typing a commercial L-L voltage (208/400/480V) re-routes the result to three-phase; 277V stays on single-phase because it's the L-N lighting leg of a 480Y/277V wye; 12/24V re-routes to DC.
Formulas
DC: Amps to Watts
P(W) = I(A) × V(V)
AC Single Phase (PF = 0.85)
P(W) = PF × I(A) × V(V)
AC Three Phase (PF = 0.85)
P(W) = √3 × PF × I(A) × VL-L, where VL-L is the line-to-line voltage
What Uses 850A at 480V?
Load Context at 480V
480V is a commercial or industrial panel voltage. At 850A per line on a 480V three-phase branch, the load is dedicated hardwired equipment sized from its own nameplate FLA under NEC 430 or 440 motor and HVAC provisions, not a consumer-appliance checklist. A conversion page cannot map an exact amperage to a specific equipment type; that depends on the equipment nameplate you are actually installing.
Monthly Running Cost
As a rough reference only, running 600,675.22W for 8 hours daily at the US residential average of $0.17/kWh works out to about $24,507.55 per month. A residential kWh rate does not apply to a 480V commercial or industrial service. Commercial and industrial accounts at this voltage are billed on demand charges, time-of-use brackets, and power-factor penalties that a flat residential kWh rate does not capture. Use this number as a ballpark for order of magnitude; for a real cost figure, plug your actual commercial rate into the energy-cost calculator or read it off your own utility bill.
AC Conversion Detail
On DC, 850A at 480V delivers a full 408,000W. On AC single-phase with a power factor of 0.85, the same current only delivers 346,800W of real power because the remaining capacity goes to reactive current. Three-phase at the same line current delivers 600,675.22W total across all three conductors.
| Circuit Type | Formula | Result |
|---|---|---|
| DC | 850 × 480 | 408,000 W |
| AC Single Phase (PF 0.85) | 0.85 × 850 × 480 | 346,800 W |
| AC Three Phase (PF 0.85) | 1.732 × 0.85 × 850 × 480 | 600,675.22 W |
Power Output by Load Type
The same 850A circuit at 480V delivers different real power depending on the load, computed on the same three-phase L-L basis the rest of the page uses:
| Load Type | PF | Real Power (850A at 480V, three-phase L-L) |
|---|---|---|
| Resistive (heaters, incandescent) | 1 | 706,676.73 W |
| Fluorescent lamps | 0.95 | 671,342.89 W |
| LED lighting | 0.9 | 636,009.06 W |
| Synchronous motors | 0.9 | 636,009.06 W |
| Typical mixed loads | 0.85 | 600,675.22 W |
| Induction motors (full load) | 0.8 | 565,341.38 W |
| Computers (without PFC) | 0.65 | 459,339.87 W |
| Induction motors (no load) | 0.35 | 247,336.86 W |
Other Amperages at 480V
| Amps | DC Watts | AC 3-Phase Watts (PF 0.85, L-L) |
|---|---|---|
| 60A | 28,800 W | 42,400.6 W |
| 70A | 33,600 W | 49,467.37 W |
| 80A | 38,400 W | 56,534.14 W |
| 100A | 48,000 W | 70,667.67 W |
| 125A | 60,000 W | 88,334.59 W |
| 150A | 72,000 W | 106,001.51 W |
| 175A | 84,000 W | 123,668.43 W |
| 200A | 96,000 W | 141,335.35 W |
| 225A | 108,000 W | 159,002.26 W |
| 250A | 120,000 W | 176,669.18 W |
| 300A | 144,000 W | 212,003.02 W |
| 350A | 168,000 W | 247,336.86 W |
| 400A | 192,000 W | 282,670.69 W |
| 500A | 240,000 W | 353,338.36 W |
| 600A | 288,000 W | 424,006.04 W |