Need a repair fast?
Call 1-800-229-5350 day or night!
client log in
our locations
contact us

AC Servo Motors

Servo motors are variable position electrical motors that control the action of a mechanical device in a servo mechanism. Industrial servo motors are available in a broad range of sizes and types. An AC motor is an electric motor driven by an alternating current. 

AC servo motors will typically be coupled with an encoder for precise control. They can be used to position ball screws, as well as a variety of geared devices.

They commonly consist of two basic parts; an outside stationary stator, having coils supplied with alternating current to produce a rotating magnetic field, and an inside rotor, attached to the output shaft that is given a torque by the rotating field.


There are two main types of AC motors, depending on the type of rotor used. The first type is the induction motor, which runs slightly slower than the supply frequency. The second type is the synchronous motor, which does not rely on induction and, as a result, can rotate exactly at the supply frequency or a sub-multiple of the supply frequency. The magnetic field on the rotor is either generated by current delivered through slip rings or by a permanent magnet.

Other types of motors include eddy current motors, and also AC/DC mechanically commutated machines, in which speed is dependent on voltage and winding connection.

AC servo motors can be extremely reliable, but, when they fail, you can rely on Paragon Technologies’ qualified technicians to get them back to top working order again quickly, reducing your down-time and lowering the overall cost of your repair dramatically.

Repair Procedures:

  • Hypot and Megohm test the windings for shorts to ground during run-in and run-out.
  • Verify magnet strength and shorts between phases with back EMF testing.
  • Recondition or rewind windings.
  • Replace machine pilot, shaft and mounting area, if needed.
  • Replace any damaged connections.
  • Verify encoder operation with custom software design to check optics, processor and communication signals.
  • Run on a system drive and paint to specs.

Some of the AC Servo Motor Brands We Repair:

  • ABB
  • Allen Bradley
  • Baldor
  • Baumuller
  • Cleveland Motor
  • Emerson
  • Fanuc
  • Getty's
  • Indramat
  • Mitsubishi
  • Modicon
  • Moog
  • Panasonic
  • Yaskawa
  • and many more