How to Reverse Directions on a 220 Volt Electric Motor
Electric motors operate by taking advantage of the rotation of magnetic fields to convert electrical energy to physical energy. The magnetic field is set in motion by application of electrical current; subsequently the field's rotation can be reversed by reversing the current.
This article covers the basic procedure for DC, AC and three-phase AC motors.
Things You Will Need
- Needle-nose pliers
- Socket wrench set or nut driver set
Most motors will have wiring diagrams on a plate somewhere on the motor housing.
Always turn off power to the motor before attempting any change of wiring. If you turn off power at the breaker/fuse level, be sure to mark the breaker/fuse to avoid activation mid-procedure. Always test your motor after changing the wiring to be sure rotation has changed and that it will not overheat. Consult the owner's manual if you are uncertain about the wiring of your motor.
Remove the faceplate covering the wiring on your motor using a screwdriver.
Remove the positive and negative leads on a DC motor from their respective terminals and replace them on the opposite terminals.
Locate the starter leads on a standard AC motor. These are usually denoted 5 and 8, and are commonly push-in connectors. If the motor is large or industrial, the leads may be held by wire nuts.
Remove starter leads 5 and 8 with your needle-nose pliers or nut driver/socket wrench, and replace them in the opposite terminals. Be certain you have a good connection when the wires are replaced.
Locate the power leads on a three-phase AC motor; these are commonly denoted 1, 2 and 3 or T1, T2 and T3. As with standard AC motors, these may be push-in connected or wire-nut connected. Select either the needle-nose pliers or nut driver/socket wrench set, respectively, and use the appropriate tool.
Remove any two of the power leads, and replace them in the opposite position. It does not matter which two of the three leads are switched. Again, be sure to have a good connection when you replace the leads.
Replace the face-plate with your screwdriver.
Alex Cosby began writing professionally in 2007. His background is in information technology and he has written professionally applied user guides in the field. He holds a Bachelor of Arts in history from the University of New Mexico.