Home
Back
Electrical Power Formula:
| From: | To: |
The conversion from watts to current is a fundamental electrical calculation that determines the current flow (in amperes) given the power (in watts) and voltage (in volts). This is based on Ohm's Law and the power formula in electrical circuits.
The calculator uses the electrical power formula:
Where:
Explanation: The formula shows that current is directly proportional to power and inversely proportional to voltage. For a given power, higher voltage systems require less current.
Details: Calculating current is essential for circuit design, selecting appropriate wire gauges, determining fuse/breaker sizes, and ensuring electrical safety in both AC and DC systems.
Tips: Enter power in watts and voltage in volts. Both values must be positive numbers. The calculator will compute the current in amperes.
Q1: Does this formula work for both AC and DC?
A: For DC circuits, this formula works directly. For AC circuits, this gives the apparent current - for real current you need to consider power factor.
Q2: What's the difference between watts and volt-amps?
A: Watts represent real power, while volt-amps represent apparent power. They're equal in DC circuits or AC circuits with purely resistive loads.
Q3: Why is current important in electrical design?
A: Current determines wire sizing (to prevent overheating), protection device ratings, and voltage drop calculations in circuits.
Q4: How does voltage affect current for the same power?
A: Higher voltage systems require less current to deliver the same power, which is why high-voltage transmission is used for power distribution.
Q5: Can I use this for three-phase calculations?
A: For balanced three-phase systems, use \( I = P / (V \times \sqrt{3} \times PF) \) where PF is power factor (typically 0.8-1.0).