Siemens SINAMICS S120 Function Manual page 527

● In the case of multiple infeed units, the systems must be supplied by a common infeed point.
Different networks are, as a result, not permissible.
● A derating factor of 5% must be taken into consideration, regardless of the number of ALMs
connected in parallel.
Active Line Modules (Booksize format)
Active Line Modules (ALM) in the Booksize format can be connected in parallel in power
versions 55 kW, 80 kW and 120 kW. The following preconditions and rules must be carefully
observed when connecting Active Line Modules in the Booksize format in parallel.
Requirements
When connecting Active Line Modules in the Booksize format in parallel, the following power
unit-specific requirements apply:
● Booksize format
● When commissioning ALMs of power class 55 kW, 80 kW or 120 kW in parallel, a firmware
version ≥ V5.2 must be available.
Rules
The following rules must be observed when connecting Active Line Modules (ALM) of the
Booksize format in parallel:
● Up to 2 identical ALMs can be connected in parallel.
● Together with the ALM parallel connection, both VECTOR as well as SERVO Motor
Modules can be used.
● A common Control Unit (CU) must always be used to implement the parallel connection.
● In the case of multiple infeed units, the systems must be supplied by a common infeed point.
Different networks are, as a result, not permissible.
● A derating factor of 5 % must be taken into consideration.
Balancing the currents
The following measures help to ensure balanced currents in parallel connections of Active Line
Modules:
● Reactors in the Active Interface Modules.
● Use of symmetrical power cabling between the transformer and the parallel-connected
Active Interface Modules / Active Line Modules (cables of identical type with the same cross-
section and length).
Redundant parallel connection of Active Line Modules with several CUs
For a description of parallel connections of multiple Active Line Modules controlled by assigned
Control Units, please refer to chapter "Master/slave function for Active Infeed (Page 506)".
Modules with different power ratings can be used.
Drive functions
Function Manual, 06/2019, 6SL3097-5AB00-0BP2
Function modules
9.10 Parallel connection of power units
525