Siemens Sinamics S120 Manual page 337

Note
Determining the appropriate biocide
The type of bacteria determines the biocide.
The concentration must be adapted to be in compliance with what the manufacturer
recommends.
It is not permissible that biocides and antifreeze are mixed.
Antifreeze already has a biocidal effect in the minimum concentration specified above.
Inhibitors
When using one of the approved antifreezes, an inhibitor is already included with the
specified concentration.
When operated without antifreeze, then Fuchs Anticorit S 2000 A inhibitor must be added
with a ratio of 4 ... 5 %.
Liquid-cooled chassis power units
Manual, (GH7), 11/2016, 6SL3097-4AM00-0BP7
Cooling circuit, coolant properties and protection against condensation
9.2 Coolant definition
337