Siemens SINAMICS S120 Equipment Manual page 473

Figure 8-21
CAUTION
The air guidance and arrangement of the cooling equipment must be chosen in such a way
as to prevent condensation from forming.
If necessary, cabinet enclosure heating may have to be installed.
If air conditioners are used, the relative air humidity of the expelled air increases as the air in
the air conditioner cools and may exceed the dew point. If the relative humidity of the air
entering the SINAMICS equipment is over 80 % for an extended period of time, the
insulation in the equipment may fail to function properly due to electrochemical reactions
(see System Overview). Using air baffle plates, for example, you must ensure that the cold
air expelled from the air conditioner mixes with warm air in the cabinet before it enters the
equipment. This reduces the relative air humidity to uncritical values.
Booksize Power Units
Equipment Manual, (GH2), 07/2007, 6SL3097-2AC00-0BP5
Examples of cabinet ventilation
Cabinet Design and EMC Booksize
8.7 Cooling
473