ABB Multi-Motor Setup With ABB Micro Drives

There are several ways to build an ABB multi-motor setup with ABB micro drives. Master-slave control, parallel control of motors and combinations of these two ways. The most typical ABB multi-motor setup for compact drives is the parallel control, which means that several motors are powered by one inverter (parallel connection of motor windings). The benefits of such approach are that there is only one inverter to startup, and that less time and effort is needed for the installation work. Multi-motor setup is possible only with asynchronous motors.

1.) Motors (3 1.5 kW) 2.) Load 3.) Rollers

Correct selection of drive is critical with this kind of ABB multi-motor setup. This is due to the fact that increased amount of common mode current will reduce the loading current capability of the drive.Factors that affect drive load ability and the amount of common mode current:

  • Total length of motor cabling
  • Total amount of parallel motors (motor size)
  • Amount of parallel motor cables
  • Motor cable type (shielded cable has higher capacitance than un-shielded)
  • Common output choke for all motors (thermal current must be 1.2 times total sum of motor currents)

The drive is selected based on the sum of the connected motor powers. See the table below to indicate the drive type depending the total motor power. Typically, also the use of external output chokes is recommended and the maximum motor cable length is more limited than with a single motor connection. When one drive controls several motors, only scalar control should be used. Motor parameters (PN, I2N) are given as the sum of the nominal values of the motors. Nominal speed is given as an average of the motor rated speeds. It is recommended to limit the maximum current according to the actual need and it should not exceed 1.1 I2N (parameter 2003 MAX CURRENT). Only 4 kHz switching frequency is allowed to be used. When multiple motors are connected, the sum of the output cable lengths must not exceed the maximum allowed cable length (see table below). Cables should be separated as close to the drive as possible. If motor contactors are used, switching the contactors during operation is not recommended.

Only trained technicians should perform an ABB multi-motor setup. To learn more about ABB multi-motor setup, visit the ABB Website. For ABB low voltage drive quotes, contact Precision Electric.