Siemens SINAMICS S120 Equipment Manual page 234

Cooling circuit and coolant properties
8.1 Cooling circuits
Figure 8-4 Pressure drop as a function of volumetric flow
Water cooling systems with series-connected SINAMICS units cannot be recommended for
the following reasons:
● The risk of cavitation and abrasion increases as a result of the high total volumetric flow.
● It is not possible to connect SINAMICS S120 in series because the total volumetric flow
The characteristic curves for the pressure drop across the heat sinks as a function of the
volumetric flow vary depending on the temperature and the Antifrogen N / water coolant mix,
as can be seen in the following figures.
232
inherent to any constellation of series connection requires system pressures in the
600 kPa range or above.
Chassis Liquid Cooled Power Units
Manual, (GH7), 01/2011, 6SL3097-4AM00-0BP1