Siemens Sinamics S120 Manual page 336

Cooling circuit, coolant properties and protection against condensation
9.2 Coolant definition
NOTICE
Material damage caused by incorrectly adding antifreeze
Incorrectly adding antifreeze to the cooling circuit can result in material damage caused by
corrosion and cooling circuit leaks.
• Always mix the coolant outside the cooling circuit before filling it.
• Do not add the individual cooling components one after the other.
NOTICE
Damage caused by leaks if the appropriate concentration of antifreeze is not used
An insufficient concentration of antifreeze can result in material damage caused by
corrosion and cooling circuit leaks.
• Regularly check the antifreeze concentration. Add the appropriate amount of antifreeze
NOTICE
Material damage caused by mixing different antifreeze products
Incorrectly adding antifreeze to the cooling circuit can result in material damage caused by
corrosion and cooling circuit leaks.
• Do not use different antifreeze products in a common cooling circuit.
• When changing the antifreeze, you must first empty the cooling circuit and flush it out
Biocide
Cooling circuits with soft water (°DH>4) are susceptible to microbes. The risk of corrosion
caused by microbes is virtually non-existent in chlorinated drinking water systems.
No strain of bacteria can survive when the appropriate quantity of antifreeze is added.
The following types of bacteria are encountered in practice:
● Slime-forming bacteria
● Corrosive bacteria
● Iron-depositing bacteria
The type of bacteria determines the suitability of a biocide. At least one water analysis per
annum (to determine the number of bacterial colonies) is recommended. We recommend
that a biocide is used depending on the ambient conditions – and that the compatibility with
the components in the cooling circuit is carefully checked.
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when required.
before filling the new coolant. To do this, refer to the instructions provided by the
manufacturer of the antifreeze.
Liquid-cooled chassis power units
Manual, (GH7), 11/2016, 6SL3097-4AM00-0BP7