A technician is troubleshooting a three-phase motor control circuit. The PLC output for the motor starter coil energizes, but the motor does not start, and the starter's auxiliary contacts are not changing state. A Voltmeter across terminals A1 and A2 of the starter coil reads 120 V AC. What is the most likely issue?

Question: A technician is troubleshooting a three-phase motor control circuit. The PLC output for the motor starter coil energizes, but the motor does not start, and the starter's auxiliary contacts are not changing state. A Voltmeter across terminals A1 and A2 of the starter coil reads 120 V AC. What is the most likely issue?

Answer options:

• The motor has an open winding.
• The starter's overload protection has tripped. ✅ The starter coil is open-circuited.
• There is a phase imbalance in the supply voltage.

Correct answer: The starter coil is open-circuited.

Explanation: If the PLC output is energizing and 120 V AC is measured across the starter coil, but the starter does not pull in, it indicates that the coil itself is open-circuited. An open coil will not create a magnetic field to close the contacts, even if voltage is applied. Options 1, 2, and 4 would not prevent the starter coil from energizing if voltage was present across it.