How to Terminate AC Motors

AC power comes out of wall sockets.

Any motor powered by alternating current (AC) is considered an AC motor. Alternating current typically comes from power plants through wiring and emerges through sockets, while DC (direct current) comes from batteries. There are two different types of AC motors: the synchronous motor and the induction motor. Terminating either type of AC motor so that it does not continue to turn over after you've unplugged it involves the same process.

Things You'll Need

• Direct current (DC) supply
• Wire
• Electrode

Instructions

1. Run a wire extending from the DC supply so that it is ready before you turn off the AC motor. Adding DC power will actually serve as a brake for the motor.

2. Unhook the motor from the AC supply. This could involve unplugging the device from the wall, or it could involve breaking the contact in the circuit at some point.

3. Touch the wire from the DC supply to any of the AC motor's coils. This will result in a magnetic field which will slow the motor shaft down. If you don't need the motor to come to a complete stop, you can break this connection when the motor speed reaches acceptable levels.

Tips & Warnings

• To shorten the amount of time it takes for the motor to stop or slow, increase the amount of power from your DC source.

• Be careful when dealing with current and wiring. Only touch insulated parts and keep yourself grounded.

References

• Electric Motors; AC Motor - Basics of AC Motor Design Engineering; 2011
• All About Circuits: AC Motor Control Circuits

Resources

• PDH Engineer: How to Start and How to Stop: AC/DC Motor Control