Convert apparent power to current
| VA | @120V |
|---|---|
| 500 VA | 4.2 A |
| 1000 VA | 8.3 A |
| 1500 VA | 12.5 A |
To find the current draw of a device rated in VA, divide by the voltage. This is useful for sizing circuits, breakers, and cables for UPS systems and other equipment.
Single-phase: Amps = VA / Volts. Three-phase: Amps = VA / (Volts × 1.732).
Divide VA by voltage. Single-phase: Amps = VA / V. Three-phase: Amps = VA / (V × √3). Example: 1500VA at 120V = 12.5 amps.
At 120V: 1500 / 120 = 12.5 amps maximum draw. At 240V: 1500 / 240 = 6.25 amps. This is the maximum the UPS can supply, not necessarily what your load draws.
VA (volt-amperes) measures apparent power. Amps measures current flow. VA = Volts × Amps. You need to know the voltage to convert between them.
Convert UPS VA to amps, then size the circuit at 125% for continuous loads. A 1500VA UPS (12.5A at 120V) needs a 15A circuit minimum, 20A recommended.