4.2.5 Cooling and Airow Requirements
The recommendations provided in this section are necessary for eective cooling of the drive modules within the panel
enclosure. Each drive module contains a heat sink fan and a mixing fan. Typical enclosure designs utilize door fans along
with the drive module fans to remove waste heat from the enclosure.
Danfoss provides several back-channel cooling kits as options. These kits remove 85% of the waste heat from the enclosure,
reducing the need for large door fans.
NOTICE
Make sure that the total ow of the cabinet fans meets the recommended airow.
Drive module cooling fans
The drive module is equipped with a heat sink fan, which provides the required
ow rate of 840 m
3
/h (500 cfm) across the
heat sink. Also, there is a cooling fan mounted on the top of the unit, and a small 24 V DC mixing fan mounted under the
input plate that operates any time the drive module is powered on.
In each drive module, the power card provides DC voltage to power the fans. The mixing fan is powered by 24 V DC from
the main switch mode power supply. The heat sink fan and the top fan are powered by 48 V DC from a dedicated switch
mode power supply on the power card. Each fan has a tachometer feedback to the control card to conrm that the fan is
operating correctly. On/o and speed control of the fans help reduce unnecessary acoustical noise and extend the life of the
fans.
Cabinet fans
When the back-channel option is not used, fans mounted in the cabinet must remove all the heat generated inside the
enclosure.
For each enclosure housing 2 drive module, the cabinet fan ow recommendation is as follows:
•
When back-channel cooling is used, 680 m
3
/h (400 cfm) ow is recommended.
•
When back-channel cooling is not used, 4080 m
3
/h (2400 cfm) ow is recommended.
Illustration 4.4 Airow, Standard Unit (Left), Bottom/Top Cooling Kit (Middle), and Back/Back Cooling Kit (Right)
Mechanical Installation Installation Guide
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