How to Wire an AC Electric Motor
Wiring an AC electric motor is not particularly difficult if the manufacturer's manual is available. But if the manual cannot be found, the job becomes tougher.
In all cases, if you're unsure about how the motor should be connected, consult an expert as incorrectly wiring a motor can lead to a shocking hazard or injury. If the wiring schematic cannot be found, it may be wiser to purchase a new motor rather than take a chance on something that you not sure about.
Things You Will Need
- Common hand tools
- Volt ohmmeter with probes
- Electrical terminal hardware
- Terminal crimpers
- Wire caps
Consult the Resources section below for a link on how to attach electrical terminals.
Use caution when working with electricity.
Be absolutely sure all electricity is removed from the motor circuitry before wiring any AC motor. Open the circuit breaker that will supply the power. Tag the breaker to ensure power will not be accidentally restored to the circuit.
Check the motor manufacturer's manual for recommendations on the correct wiring hookup for your application. If there is not a manual with the motor, look for a hook up schematic somewhere on the motor. The schematic may be on the exterior of the motor or possibly under an inspection plate or cover of the motor.
Consult the link below in the Resources section for the hook up chart for most modern motors. Find the correct wiring connections for your particular motor. For example, if the motor is single phase single voltage and you would like it to rotate in a counter clockwise direction, the chart shows that input power is connected to L1 and L2. For the CCW rotation, wires 1 and 8 are connected together and wires 4 and 5 are connected together.
Open the motor cover to access motor terminals. Strip the power wire ends and crimp on terminals. Connect the wiring to the motor terminals. Use wire caps to connect the wires together for the correct rotation.
Replace the cover and energize the motor circuit when the wiring hook up is completed. Make sure that the motor operates in the correct direction.
Daniel Ray has been writing for over 15 years. He has been published in "Florida Sportsman" magazine. He holds an FAA airframe and powerplant license and FCC radiotelephone license, and is also a licensed private pilot. He attended the University of South Florida.