Siemens SINAMICS S120 Equipment Manual page 257

CAUTION
Devices must not be operated in an "air short circuit", since this can damage equipment or
cause it to fail.
Suitable barriers must be in place to prevent an air short circuit.
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,
the cross sectional area of each opening must be at least 280 mm² (e.g., 7 mm x 40 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.
If dirt filters are used, the specified opening cross-sections and the filter areas must be
adjusted upwards.
CAUTION
If dirt filters are used, the specified replacement intervals must be observed.
If the filter mats are heavily contaminated, the volume of air drawn is reduced due to the
increased flow resistance. This can cause the fans integrated in the devices to overload, or it
could cause the devices themselves to overheat and become damaged.
The opening cross-sections specified in the table refer in each case to one device. If more
than one device is installed in a cabinet, the opening cross-section increases accordingly. If
the required openings cannot be made in the cabinet, the devices must be distributed across
several cabinets, which are separated from each other by means of partitions.
The warm air must be discharged via the top cover/hood or via side openings in the cabinet
at the level of the top of the device. The size of the opening cross-section must also be taken
into account here.
Chassis power units
Manual, (GH3), 10/2008, 6SL3097-2AE00-0BP3
Cabinet design and EMC
7.3 Cabinet air conditioning
257