1. What is Motor Current Calculation?

The motor current calculation determines the electrical current required by a motor based on its power rating and the supply voltage. This is fundamental for proper circuit design and protection.

2. How Does the Calculator Work?

The calculator uses Ohm's Law for power:

Where:

• \( I \) — Current in amperes (amps)
• \( P \) — Power in watts
• \( V \) — Voltage in volts

Explanation: This simple relationship shows that current is directly proportional to power and inversely proportional to voltage.

3. Importance of Current Calculation

Details: Accurate current calculation is essential for selecting proper wire sizes, circuit breakers, overload protection, and ensuring safe operation of electrical motors.

4. Using the Calculator

Tips: Enter power in watts and voltage in volts. Both values must be positive numbers. The calculator will compute the current in amperes.

5. Frequently Asked Questions (FAQ)

Q1: Is this calculation valid for AC and DC motors?
A: This simple calculation works for DC motors. For AC motors, power factor and efficiency must be considered for precise calculations.

Q2: What's the difference between input power and output power?
A: This calculator uses input power (electrical power). Output power (mechanical power) would require knowing the motor's efficiency.

Q3: How does three-phase current calculation differ?
A: Three-phase calculations require an additional factor of √3 (1.732) in the denominator when using line-to-line voltage.

Q4: Why is current calculation important for motor starting?
A: Motors typically draw 5-7 times their rated current during startup, which affects protection device selection.

Q5: How does motor load affect current?
A: Current increases with mechanical load. Full-load current is typically marked on the motor nameplate.