Siemens SINAMICS S120 Equipment Manual page 71

Principle of operation
One or more Motor Modules can be connected to the power supply network via the Basic
Line Module. The Basic Line Module provides the DC link voltage for the Motor Modules.
The Basic Line Module is suitable for direct operation on TN, IT, and TT systems.
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 electronic circuitry 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.
Parallel connection of Basic Line Modules to increase power rating
Up to four Basic 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 Basic Line Modules in parallel:
• Up to 4 identical Basic 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 7.5 % must be taken into consideration, regardless of the number of
modules connected in parallel.
Chassis Power Units Liquid Cooled
SINAMICS S120 Equipment Manual, Edition 12/2007, 6SL3097-2AM00-0BP4
Line Modules
4.2 Basic Line Modules
4-3