Coupled Motors; Operating Motors Connected To An Axis In Parallel; Master And Stoker - Siemens SIMOTICS T-1FW6 Series Configuration Manual

Coupled motors

10.1

Operating motors connected to an axis in parallel

When the torque of an individual motor is not sufficient for the drive application, then it is
possible to distribute the required torque over two or more motors.
Mount the motors on the same axis. The motors are then mechanically coupled.
You have two options for supplying the individual motors:
● Each motor is operated on its own Motor Module with its own encoder. This operation
does not represent an electrical parallel connection. The motors only operate together
mechanically. This version is not discussed in this manual.
● All of the motors are connected to the same Motor Modules. In this case, the article
numbers of all of the motors involved must be the same. The motors are then electrically
connected in parallel, and operate in the parallel mode.
Note
Country-specific safety requirements for parallel operation
Country-specific safety requirements and regulations apply when connecting motors in
parallel at a Motor Module.
For example, in the US, for special motor protection, carefully comply with the requirements
laid down in standards NFPA 70 and NFPA 79.
Notes for parallel operation
The motor power cables must be the same length in order to ensure uniform current
distribution.
When operating several motors in parallel, you must accommodate additional motors and
cables. Plan the additional installation space required.
Add the rotor moment of inertia of each motor involved to the overall moment of inertia of the
axis.
10.2

Master and stoker

The first motor in an axis is called the "master". The master defines the positive direction of
rotation of the axis. The second and each additional motor are called "stokers".
The following definitions also apply to each additional stoker.
Whether tandem or Janus arrangement is the better solution, depends on the space
requirement and the cable routing.
Naturally cooled 1FW6 built-in torque motors
Configuration Manual, 07/2017, 6SN1197-0AE01-0BP3
10
181