Siemens SINAMICS S120 Equipment Manual page 261

Note
Analyzing the liquid coolant
It is recommended that you contact the coolant manufacturer for analyzing the liquid coolant.
The coolant should be checked 3 months after the cooling circuit is filled for the first time
and, subsequently, once a year.
If the cooling water becomes cloudy, is colored, or becomes contaminated by mould spores,
the cooling circuit must be cleaned and refilled.
To better explain the coolant specifications in this document, a number of problems which
can be encountered if these specifications are ignored are listed in the table below.
Table 9- 3 Substances which can cause irreparable heat sink damage
Problem
Increase corrosion,
deposits
Semi-open cooling
circuit
Erosion/particles
Whitish deposits
Electro corrosion
Deposits, residues,
algae
Water-cooled chassis power units for common cooling circuits
Manual, 08/2017, 6SL3097-4AM10-0BP0
Cooling circuit, coolant properties and protection against condensation
Possible causes/consequences
Properties of the coolant or limit value
exceeded
Sea water
Water compliant with limit values
Chloride
Sulfate
Ingress of oxygen
Suspended solids (e.g. sand)
Excessively high total hardness
Voltage potential can be identified
Inadequate equipotential bonding
Biological contamination
Oil residue
Mechanical contamination
Countermeasure
Do not use sea water!
Use an appropriate concentration of antifreeze, cool-
ing circuit must include a pressure-relief valve.
Use the specified coolant basis and the appropriate
concentration of antifreeze.
Use the specified coolant basis and the appropriate
concentration of antifreeze.
Use a closed cooling circuit equipped with a pressure
relief valve, the specified coolant basis and the ap-
propriate concentration of antifreeze.
Rinse cooling circuit without SINAMICS devices. In-
stall dirt trap (e.g. strainer, 100 µm fine filter).
Use the specified coolant basis and the appropriate
concentration of antifreeze.
Connect all components to equipotential bonding
system. Device connected using a high ohmic hose.
Use of biocides, dirt traps (e.g. strainers, fine filters).
Use the appropriate concentration of antifreeze, flush
cooling circuit without SINAMICS.
Rinse cooling circuit without SINAMICS devices. In-
stall dirt trap (e.g. strainers, fine filters).
9.2 Coolant definition
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