Siemens Sinamics S120 Manual page 165

Operating principle
One or more Motor Modules can be connected to the power supply network via the Active
Line Module. The Active Line Module provides a constant DC link voltage for the Motor
Modules. This ensures that they are not influenced by line voltage fluctuations. The
regenerative feedback capability of the Active Line Module can be deactivated by
parameterization.
The Active Line Module is suitable for direct operation both on TN and on IT and TT
systems.
With the motors operating as generators, the Active Line Module feeds regenerative energy
into the supply network.
The Active Line Module is used for:
● Machines with high dynamic drive requirements
● Frequent braking cycles and high braking energy.
The volumetric flow of the coolant is monitored by the software. If the volumetric flow is
continuously lower than the setpoint, an alarm (A5005) is first displayed. If this alarm
remains active continually for the next 5 minutes, a fault message (F30047) is activated
which shuts down the unit.
The fans for the internal device electronics are only switched on when required.
The fans are switched on and off as a function of several factors (e.g. heat sink temperature,
ambient temperature, output current, duty cycle, ...) which means that fan operating cycles
cannot be calculated directly.
An external 24 V DC power supply is required to operate the Active Line Modules.
Parallel connection of Active Line Modules to increase power rating
Up to four Active 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 Active Line Modules in parallel:
● Up to 4 identical Active 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 derating factor of 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.
Liquid-cooled chassis power units
Manual, (GH7), 11/2016, 6SL3097-4AM00-0BP7
Line Modules
5.3 Active Line Modules
165