Siemens SINAMICS S120 Equipment Manual page 424

Cabinet design and EMC
10.3 Cabinet air conditioning
Due to the flow of air within the cabinet, the device fan draws in pre-heated air. This heats up
the components considerably and the fan does not function effectively.
NOTICE
Device failure due to air short-circuit in the control cabinet
Short-circuits in the cooling air circuit as a result of unsuitable air guidance can result in
overheating in the electrical cabinet and in turn failure of devices.
• Install suitable barriers in the control cabinet in order to prevent an air short-circuit from
NOTICE
Failure of devices as a result of the different cooling concepts of the Chassis and Chassis-2
power units
When using Chassis and Chassis-2 power units in one electrical cabinet, if suitable
partitions are not used, then the devices can fail as a result of the different cooling
concepts.
• Install suitable partitions between the cabinet panels where Chassis and Chassis-2
Barriers must be installed in such a way that no air can flow along the outer sides on the top
and bottom of the devices. In particular, air must be prevented from flowing from the top
(warm discharged air) to the bottom (cold cooling air). Suitable plates can be used as
barriers. The barriers must reach up to the side panels or cabinet doors. They must be set
up in such a way that the outgoing air current is not forced into the cabinet cross-beams, but
is instead diverted around them. Barriers must be in place for all degrees of protection higher
than IP20.
The cabinets adjacent to the converter cabinets must also be taken into account when
barriers are installed.
To ensure adequate ventilation of the equipment, the minimum opening sizes specified in the
following table must be observed.
The specified opening cross-sections comprise several small openings. To ensure that
pressure loss is kept to a minimum and that the flow resistance does not become too great
at these mesh-type openings, the cross sectional area of each opening must be around at
least 190 mm² (e.g. 7.5 mm x 25 mm or 9.5 mm x 20 mm).
To ensure that the devices operate continuously, suitable measures must be taken to
prevent the ingress of dirt and dust. Wire lattices (wire fabric DIN 4189-St-vzk-1x0.28) or
filter mats (min. filter class G2) must be used for this purpose. The choice of filter mats
depends on the required degree of protection and the ambient conditions. If cabinets are
installed in an environment containing fine dust particles or oil vapors, micro-filter mats must
be used to prevent the devices from becoming contaminated.
422
occurring.
power units are mounted.
Air-cooled chassis power units
Manual, 07/2019, 6SL3097-4AE00-0BP9