Which statement describes the function of a phase rotation tester?

Which statement describes the function of a phase rotation tester?

• A. It measures the temperature of the circuit
• B. It measures resistance
• C. It determines the direction of rotation in a three-phase circuit
• D. It measures DC voltage

Answer: (C)

Phase rotation testing is about the order of the three-phase voltages and how that order determines motor direction. A phase rotation tester checks which phase is leading and shows the sequence, so you can confirm the motor will spin in the intended direction. In a three-phase system, swapping two wires changes the sequence and reverses rotation, which can cause damage or safety issues if a motor starts the wrong way. That’s why this tool is used before starting equipment to ensure correct rotation. The other activities listed aren’t what this tool does. It doesn’t measure temperature, resistance, or DC voltage.

Phase rotation testing is about the order of the three-phase voltages and how that order determines motor direction. A phase rotation tester checks which phase is leading and shows the sequence, so you can confirm the motor will spin in the intended direction. In a three-phase system, swapping two wires changes the sequence and reverses rotation, which can cause damage or safety issues if a motor starts the wrong way. That’s why this tool is used before starting equipment to ensure correct rotation.

The other activities listed aren’t what this tool does. It doesn’t measure temperature, resistance, or DC voltage.