如何计算Watts to Amps
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A watts to amps converter calculates electrical current from power and voltage using Ohm's law. It is used for sizing circuit breakers, fuses, and cables for electrical installations.
公式
A (DC) = W / V; A (AC) = W / (V × PF)
- W
- Power (W) — Electrical power in watts
- V
- Voltage (V) — Electrical potential difference in volts
- A
- Current (A) — Electrical current in amperes
- PF
- Power factor ((dimensionless)) — AC circuits only; typically 0.8–1.0
分步指南
- 1Amps = Watts ÷ Volts (DC circuits)
- 2Amps = Watts ÷ (Volts × Power Factor) (AC circuits)
- 3Standard voltages: 120V (US), 230V (UK/EU), 240V (AU)
- 4Power factor for resistive loads = 1.0
例题解析
输入
2400W appliance at 240V
结果
10 amps
输入
1200W microwave at 120V
结果
10 amps
输入
3000W oven at 240V
结果
12.5 amps
常见问题
What is the difference between watts and amps?
Watts measure power (energy per unit time). Amps measure current flow. Relationship: Watts = Volts × Amps.
Why do I need to know this?
For sizing circuit breakers, fuses, and electrical cables. An undersized wire can overheat; an incorrectly rated breaker won't protect the circuit.
What is power factor?
In AC circuits, power factor accounts for reactive loads (motors, inductors). A pure resistive load has PF = 1.0. Motors typically have PF = 0.8–0.95.
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