10  Cooling System
10.1  Installation of liquid-cooled devices
In continuous operation liquid-cooled drive converters are operated with lower tempera-
turethanair-cooledinverters.Thishaspositiveeectsonlifetime-relevantcomponents
such as fan and DC link capacitors and power modules (IGBT). Also the temperature de-
pendentswitchinglossesarepositivelyeected.Theuseofliquid-cooledCOMBIVERT
driveconvertersisoeredinthedrivetechnology,becausethereareprocess-caused
coolants available with some applications. 
10.1.1  Heat sink and operating pressure
Design system Material (voltages)
Max. operating  
pressure
Connecting duct
Extrusion casting heat sink Aluminium  (-1.67 V) 10 bar 0000650-G140
Cooling plate with 
pressed pipes
Stainless steel (-1.04V) 6 bar upon request
Table 21:  Heat sink and operating pressure
The aluminium liquid coolers are sealed by sealing rings and posses a surface protec-
tion (anodized) even in the ducts. 
NOTICE
In order to avoid a deformation of the heat sink and the damages there-
by,theindicatedmax.operatingpressuremaynotbeexceededbriey
also by pressure peaks.
Pay attention to the Directive 2014/68/EU of pressure equipment.
10.1.2  Materials in the cooling cicuit
For the screw connections and also for the metallic articles in the cooling circuit which 
are in contact with the coolant (electrolyte) a material is to be selected, which forms a 
smallvoltagedierencetotheheatsinkinordertoavoidcontactcorrosionand/orpitting
corrosion (electrochemical series, see table). An aluminum screw connection or ZnNi 
coated steel screw connection is recommended. Other materials must be examined in 
eachcasebeforeemployment.Thespeciccaseofapplicationmustbecheckedbythe
customerintuningofthecompletecoolingcircuitandmustbeclassiedaccordingtothe
used materials. With hoses and seals take care that halogen-free materials are used.
A liability for occuring damages by wrongly used materials and from this resulting corro-
sion cannot be taken over!
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 COOLING  SYSTEM