nvent Schroff 14579-040, User Manual

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14579-040 (PXIe System)
R1.5, January 2021 Cooling 17
4 Cooling
The PXIe boards are cooled by forced air convection through 3 speed controlled 12 VDC axial
fans.
The air enters the subrack at the perforated bottom panel into the bottom air plenum. As the
air passes across the hot components on the Front Boards, heat is carried away by forced
convection.
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The air exits the subrack at the top, is drawn into the upper plenum, turns 90°, passes the
modules located at the backplane‘s rear side and is exhausted out the rear of the subrack by
the 3 fans.
The average cooling capacity of the PXIe chassis is 50 W per slot at a Delta T of 20 °C. The
actual heat dissipation for a specific slot depends on the pressure drop of the card used and
the occupancy of the adjacent slots.
For high performance cards, the slot with the highest air flow should be used and the air flow
of adjacent slots should be reduced by air baffles.
Figure 4: Air Flow
Caution!
To maintain proper airflow, all open slots must be covered with filler panels. The filler panel
should include an airflow baffle that extends to backplane.
For desktop use, unfold the front tip-up feet for optimal cooling efficiency.
For rack mounting, at least 1 U (44.5 mm/1.75 in.) clearance below the chassis is required.