Biocide Additives (Only If Required) - Siemens SINAMICS S120 Manual

13.2.4

Biocide additives (only if required)

Closed 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.
If Antifrogen N antifreeze is used with a concentration of 20% or higher, it can be assumed
that there is an adequate biocide effect.
The following types of bacteria are encountered in practice:
● Bacteria that cause the formation of slime
● Corrosive bacteria
● Bacteria that cause deposits of iron
The type of bacteria determines the suitability of a biocide. A water analysis must be carried
out once a year to determine the number of bacterial colonies. Suitable biocides are
available, for example, from Nalco.
Recommendation
Twice a month Nalco N 77352 is added intermittently. The dosing quantity is 5 to 15 mg/100
liters of cooling water. This product has no adverse effect on Nalco 00GE056 corrosion
inhibitor.
Note
The type of bacteria determines the biocide.
The manufacturer's recommendations must be followed regarding the dosage and
compatibility with any inhibitor used.
It is not permissible that biocides and Antifrogen N are mixed.
Booksize Power Units
Manual, (GH2), 07/2016, 6SL3097-4AC00-0BP8
Cooling circuit and coolant properties
13.2 Coolant requirements
781