Motor Controller Repair


      A motor controller is a device or group of devices which have the role of governing the behavior of an electric motor according to some predefined parameters. Usually the tasks implemented via motor controllers are:

  • Starting and/or stopping the motor;
  • Selecting rotation direction;
  • Selection and regulation of motor speed;
  • Regulation or limiting of the torque;
  • Protection against overload.

      Even if some of of these can be implemented using manual control (for example speed regulation) most of the controllers used in industry are designed to be automatic, allowing a great control of the motor. Also, due to increase level of automation required, many of them implement also remote control capabilities, to allow them to be used in complex computer controlled environments.


      Motor Controllers can be divided into different categories, according to their implemented functions of motor control:

  • Motor Starters;
  • Adjustable Speed Drives;
  • Intelligent controllers;
  • Servo Controllers;
  • Stepper Motor Controllers.


      Motor Starters

      For a small motor (DC or AC) the starting process can be as simple of just switching it on. But for large motors it’s required a specialized switching unit called a motor starter or motor contactor. This will control the amount of voltage applied to the motor, through a  voltage reduction device and then increases the voltage gradually or in steps, according to the motor characteristics.


      Adjustable-speed drives

      An adjustable-speed drive (ASD) or variable-speed drive (VSD) is an electronic equipment that provides the control of the rotational speed of a motor.  Most of modern ASDs and VSDs units  also implement soft motor starting capabilities.


      Intelligent controllers

      An Intelligent Motor Controller (IMC) uses microprocessor  processing power to implement various ways to control power electronic devices used for motor control. This lead to the possibility to monitor and adjust the motor torque to match with its momentary  load. This can be done either by reducing the voltage to the AC terminals and/or by  lowering the current. Most of the time this devices improve the  energy efficiency of the motors that run under light load for a large part of the time, resulting in less heat, noise, and vibrations generated by the motor.


      Servo controllers

      Servo controllers are designed to enable the following features of a servo motor:

  • precise closed loop position control;
  • fast acceleration rates;
  • precise speed control.

      Servo motors may be made from several motor types, mainly by the addition of a position feedback, the most common types being:

  • brushed DC motor
  • brushless DC motors
  • AC servo motors

      Servo controllers use the motor feedback to close the control loop. The feedback is commonly implemented with encoders, resolvers, and Hall effect sensors to directly measure the rotor’s position.


      Stepper motor controllers

      A stepper motor is a dedicated type of motor, its main characteristics being: brushless, high pole count and synchronous polyphase motor. Control is usually done in open loop, assuming that the rotor position is following a controlled rotating field. Stepper motors can provide a very precise positioning  much simpler and cheaper than implementing a closed loop controls.


      Our team of highly qualified technicians can perform professional motor controller repair for all kind of motors. We have the experience required, and also the test equipment needed to find the problem of any  unit, regardless of its complexity. After the fault is found we will provide you an estimation of the repair cost, leaving you to decide if the repair will be done. Usually the repair cost is less than 50% of the price of a new unit.

      After the approval, we will repair the motor controller and test it to assure the customer that the unit will comply with all the manufacturer specified characteristics. We will guarantee our repair with up to a full year warranty.

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