Siemens SINAMICS S120 Operating Instructions Manual page 63

If the cooling unit is not used for longer periods of time, there is a risk that parts of the system
will be clogged up with ethylene glycol. If the cooling unit is not used after it has been drained
for a longer period of time, then we recommend that the system is flushed using clean water,
e.g. municipal water. This flushes out coolant deposits.
To prevent oxidation, all water residues must be removed and the plant must be dry. Therefore,
after flushing, empty the system using nitrogen.
Disposal
Dispose of the equipment-water mixture and the water used for flushing, taking into account
local regulations. Reuse is preferred over disposal. Please refer to the disposal notes of the
coolant manufacturer.
Siemens Drives & PLCs
Applications for Cabinet Modules, liquid cooled
Operating Instructions, 04/2015, A5E35974555A
Preparations for use
3.5 Storage
63