Siemens SINAMICS S120 Equipment Manual page 246

Cooling circuit, coolant properties and protection against condensation
9.1 Cooling circuits
Note
Requirements regarding the coolant reservoir
It must be guaranteed that the coolant is cooled down in the coolant reservoir.
Note
Arrangement of the devices in the cooling circuit
When arranging the devices in the cooling circuit, please note that the SINAMICS S120
devices must always be positioned upstream of the motors.
Dirt traps (strainer) with a mesh width ≤100 µm, at least one pressure measuring point and a
sight glass are important for service.
For the dirt trap, the automatic backflushing version (Hydac company, Order No.: ATF-1-
EPZ4-P-E-16-0-0/UKS1-100) or similar is recommended; this must always be connected on
the pressure side of the pump.
The customer must take measures (e.g. by monitoring the level) that the level in the coolant
reservoir does not fall below a certain height.
Air bubbles in the coolant can cause the device to overheat. Permanently occurring air
bubbles indicate a fault in the cooling arrangement.
246
Water-cooled chassis power units for common cooling circuits
Manual, 08/2017, 6SL3097-4AM10-0BP0