Parallel Connection Of Motors - Siemens SINAMICS S120 Function Manual

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Parallel connection of motors

● STARTER commissioning tool for vector control

Function description

For simple commissioning of group drives (a number of identical motors operating on one

power unit), the number of parallel-connected motors can be entered via STARTER (only

vector control) or via the expert list (for servo and vector control) (p0306).

An equivalent motor is computed internally depending on the number of motors specified. The

motor data identification determines the data for an equivalent motor. Motors connected in

parallel can also operate on an encoder (on the 1st motor).

For information about parallel connection of Motor Modules, see Section "Parallel connection

of power units (Page 515)".

Parallel connection is characterized by the following features:

● Up to 50 motors connected in parallel can be operated on one frequency converter.

● The original motor data set (p0300 ff.) is not modified. It is merely the data set transfer to the

closed-loop control which is organized according to the number of parallel-connected

● The stationary motor data identification also works for parallel connections.

● The rotating measurement function also works if the motors can rotate without distance limit.

Uneven loading of the motors or a high degree of gear backlash will negatively affect the

accuracy of the rotating measurement result.

● The cable lengths for motors connected in parallel must be as symmetrical as possible to

afford the most even possible distribution of current among individual motors.

● Motors connected in parallel with servo control, must be individually thermally monitored.

Synchronous motors connected in parallel must have the same EMF so that no unwanted

currents flow between the motors.

Commissioning the function (STARTER)

In the STARTER commissioning tool, only motors with vector control can be commissioned.

Motors with servo control can only be connected in parallel via the expert list.

Parameter p0306 is assigned in a STARTER commissioning screen. When the subsequent

parameters are set, p0306 is included in the calculation of the current limit (p0640) and in the

Drive functions

Function Manual, 06/2019, 6SL3097-5AB00-0BP2

Basic functions

8.30 Parallel connection of motors