Cooling Air Requirement And Sizes Of Cabinet Openings - Siemens SINAMICS G130 Engineering Manual

General Engineering Information for SINAMICS
Engineering Information

Cooling air requirement and sizes of cabinet openings

The cooling air required by power units is determined by their frame size and output and also depends on the number
and size of the fans installed. One fan is provided for each power block. The required cooling air must be made
available through openings of the correct size in the cabinet. The correct sizes of opening must be provided for inlet
air and outlet air.
The specified opening sizes 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).
The table below specifies the relevant data. The opening sizes specified in the table refer in each case to one device.
If more than one unit is installed in a cabinet, the size of the opening increases accordingly. If the required openings
in the cabinet cannot be made, the units must be distributed among several cabinets which are segregated by means
of partitions.
With degrees of protection higher than IP20 and if a hood is used, an "active" hood may have to be used. An "active"
hood contains fans that blow the air current forwards. Apart from the air outlet, the hood is otherwise closed.
When choosing an "active" hood, you must ensure that the fans are sufficiently powerful to prevent air from
accumulating in the cabinet. If air accumulates, the cooling capacity is reduced. This can overheat and destroy the
equipment. The cooling capacity of the fans should at least correspond to the device fan data.
To ensure long-term operation of the equipment, measures must be taken to prevent the ingress of dirt and dust.
Wire lattices (wire cloth 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 sizes and filter areas must be increased.
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. In order to avoid this, short filter change intervals should be applied.
To ensure adequate ventilation of the equipment, the minimum opening sizes and air-flow rates specified in the
following table must be observed.
Component
S120 Chassis
Basic Line Module
Frame size FB
Frame size GB
Smart Line Module
Frame size GX
Frame size HX
Frame size JX
Active Interface Module
Frame size FI
Frame size GI
Frame sizes HI/JI
SINAMICS Engineering Manual – May 2008
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© Siemens AG
Rated power
200-400 kW at 400 V;
250-560 kW at 690 V
560-710 kW at 400 V;
900-1100 kW at 690 V
250-355 kW at 400 V;
450 kW at 690 V
500 kW at 400 V;
710 kW at 690 V
630-800 kW at 400 V;
1000-1400 kW at 690 V
132-160 kW at 400 V
235-300 kW at 400 V
380-900 kW at 400 V;
560-1400 kW at 690 V
Cooling air Minimum size of opening in cabinet
requirement
Inlet opening
[m³/s]
0.17
0.36
0.36
0.78
1.08
0.24
0.47
0.4
Outlet opening
[m²] [m²]
0.1 0.1
0.16 0.16
0.16 0.16
0.28 0.28
0.4 0.4
0.1 0.1
0.2 0.2
0.16 0.16