Siemens SINAMICS S120 Equipment Manual page 161

Parallel connection of Smart Line Modules to increase power rating
Up to four Smart Line Modules with the same power rating can be connected in parallel in
order to increase power.
The following rules must be observed when connecting Smart Line Modules in parallel:
● Up to four identical Smart Line Modules can be connected in parallel.
● A common Control Unit is required whenever the modules are connected in parallel.
● With multiple infeeds, power must be supplied to the systems from a common infeed
point (i.e. different supply systems are not permitted).
● A line reactor must be series-connected to every parallel-connected Smart Line Module.
● A derating factor of 7.5% must be taken into consideration, regardless of the number of
modules connected in parallel.
Note
Mixed operation is not possible
It is only possible to connect identical power units in parallel if all power units have the same
hardware version. Mixed operation between a power unit with Control Interface Module
(article number 6SL33xx-xxxxx–xAA3) and a power unit with Control Interface Board (article
number 6SL33xx-xxxxx–xAA0) is not possible.
NOTICE
Converter error due to missing circuit breaker wiring
If the leading contact of the circuit breaker is not wired to the OFF2 signal from the Control
Unit, the SINAMICS control reacts with the "Overvoltage" or "Undervoltage" error if the
circuit breaker is triggered.
• Connect the signal from the leading contact of the circuit breaker to the OFF2 signal
Air-cooled chassis power units
Manual, 07/2019, 6SL3097-4AE00-0BP9
from the Control Unit. In this way, the SINAMICS control is able to delete pulses from
the Smart Line Modules in good time, before the circuit breaker is opened.
Line Modules
5.3 Smart Line Modules
159