To wire a three-phase motor control circuit, first switch off the power to the circuit to be wired to the motor. Open the motor wiring box, and identify nine labeled wires. Examine the motor nameplate to determine the motor voltages and other relevant wiring information. Determine whether to wire the motor for a low or high connection, and for either Wye or Delta wiring configurations.
In Wye wiring, when connections are for low voltage of 230 volts, join motor leads 4, 5 and 6 together. To the black L1 conductor, connect motor leads 7 and 1, and to the red L2 conductor, attach motor leads 8 and 2. Attach motor leads 3 and 9 to blue L3 conductor.
For a high voltage connection, join the following motor leads together, 4 and 7, 5 and 8, and 6 and 9. To the black L1 conductor, attach motor lead 1, and then attach motor lead 2 to the red L2 conductor. Attach motor lead 3 to the blue L3 conductor before connecting a ground wire to the motor’s ground terminal.
In a Delta wiring configuration, when making connections for low voltage, first attach motor leads 1, 6 and 7 to the black L1 conductor, before connecting motor leads 2, 4 and 8 to the red L2 conductor. To the blue L3 conductor, attach motor leads 9, 5 and 3. For high voltage connections, join motor leads, 4 and 7, 6 and 9, and 5 and 8 together. Attach motor lead 1 to the black L1 conductor, motor lead 2 to the red L2 conductor, and motor lead 3 to the blue L3 conductor. Finally, connect the ground wire to the motor’s ground terminal, and then close the wiring box.