Table of contents

RoadTest: ebm-papst K4 Motor System Development Kit

Author: ravi kondeti

Creation date:

Evaluation Type: Electromechanical

Did you receive all parts the manufacturer stated would be included in the package?: True

What other parts do you consider comparable to this product?: **

What were the biggest problems encountered?: none as of now. ongoing tests ,ight introduce new ones.

Detailed Review:

Out of the box

Equipment used:

Power supply: 20V,16A

Current sense module: ACS712-20A

Arduino uno

Digital multimeter


Power supply


K4 switch box

Motor Specifications:

Voltage: 24 Volts

Torque: 0.235 N

Power: 100 W

Nominal Speed: 4000 rpm

Control: Position

Description regarding the drive:

The VDC-3-49.15-K4 motor is a 3-phase EC drive with a multi-pole magnetised neodymium magnet. The electronically commuted external rotor motor has an astonishingly high power density and a compact design. Excellent control action is achieved due to the field-orientated control with sinus commutation. The VDC-3-49.15-K4 has fully integrated control electronics with high-performance DSP and extensive interfaces. This enables particularly flexible control of the drive and the drive can therefore be adapted to different applications. The integrated temperature cut-out provides reliable protection against overload.

K4 Box Description:

  • Motor Supply: 24 volts input is connected to this terminals
  • 2 fuses are present 

1.Motor Fuse 

2.Logic fuse

  • Motor Connector: connection of power and control signals for the motor
  • RS485 terminals are present which are used to connect the K4 module to PC using a RS485 to USB converter
  • Readouts:

1.Motor V

2.Logic V




6.A IN 1



  • Input switches:

IN A, IN B, IN 1 ,IN 2

  • Analog 0-10v control dial: speed control of motor

K4 functionalities:

  • Speed controller 
  • Current controller
  • Position controller

Software Requirements:

  • Ebmpapst driveSTUDIO
  • RS485 adapter drivers

Initial Test Run (DEMO MODE):

  1. Power supply is turned and Voltage is adjusted to 24 volts
  2. Make sure connections are proper and the motor is fixed rigidly.
  3. Power on the setup and connect the RS485 adaptor to PC, open the drive studio

  4. After opening the driveSTUDIO you will be presented with the following page. Press the connect button to get the drive details as shown in the top left corner.(make sure the COM port is correct)
  5. While INA & INB are in off position, click on the service interface.
  6. Now enable either of INA or INB or both. Set the speed and current limit near to half the limit. Press left or right in velocity control to run the motor.
  7. Too high a speed increases the motor back EMF and makes the drive enter into fault state.

  8. Simply disable and enable the INx switch to RESET the drive and follow the process again.
  9. Analog dial on the switch box can be used to control the drive directly by varying the knob.

Digital Input Mode:

  1. Using the parameters window in the driveSTUDIO a predefined set of operations based on digital inputs can be configured into EEPROM.
  2. Before  configuring them make sure all the switches are in off position.
  3. Click on the “read”button which will indicate the current drive state
  4. Configure accordingly and hit the “write” button
  5. INA/INB can be set for direction and IN1/IN2 to set speed.
  6. A monitor window is present in the bottom where real time motor parameter can be observed.

Circuit diagram:

Layout of the drive is shown in the following diagram. A breaking chopper is present in the drive which can be connected to ballast resistor to maintain a stable voltage within limits, this is caused due to deceleration of motor from high speeds which will increase its back EMF and triggers either power supply or drive overvoltage fault.


Overall kit is a good way to start for a beginner in motor drives. simple software tools present a path for understanding the drive behaviour and working of the electronics in the drive. A lot more has to be experimented on the drive for performance in the long run.