Three-Phase AC Motor - U/V/W Phase Connection & Rotation Direction Animation

Change Phase Sequence (Reverse Motor Direction)

Observe how the motor rotation changes as you alter the phase sequence.

In the world of AC motors, U, V, and W are simply the three-phase power lines feeding the motor. Each one is a separate input terminal for a different AC phase, all spaced exactly 120° apart. In short, these three connections bring life to the windings inside your motor.

Quick Definition & Technical Explanation

What are U, V, W?

• U, V, W are the three output terminals of your motor or drive, directly tied to the phases of the AC power supply.
• The order you connect these phases controls the rotation direction of the motor shaft.
• Usually, you’ll see U→V→W or V→W→U. Just swap the order and you’ll instantly reverse the rotation.

Why Are They So Important in AC Motors?

This three-phase setup delivers power to the motor in the most efficient and balanced way possible.

• Continuous Power Transfer: At least one phase is always at its peak, so the motor never “starves” for power—no dead spots or stuttering.
• High Efficiency & Torque: Compared to single-phase, you get more power and starting torque for every amp.
• Smooth & Silent Operation: Three phases mean the torque is steady and ripple-free. The result? Longer motor life and reliable performance.

How Does Rotation Direction Change?

Just swap the connection order from U-V-W to V-W-U and you flip the direction of the magnetic field inside the motor. Simple trick: change the phase sequence, change the way the shaft spins.

(Bottom line: Without U, V, W, your AC motor isn’t moving an inch. But switch the order and you decide exactly which way it turns. That’s the whole secret!)