Kontron NSC2U IP Network Server - Manual (Page 23)

Kontron IP Network Server NSC2U
December 2009 Product Guide, rev. 1.423
Features—NSC2U Server
2.10.4 Hard Disk Drive and Power Supply Cooling
Airflow to cool the hard disk drives is provided by the fans that are integrated into the
PSUs. The airflow is adequate even with a single PSU installed as long as a filler panel is
installed in the other PSU slot.
2.10.5 Fan Speed Control
The server board contains Pulse Width Modulation (PWM) circuits, which control the
12 Vdc fan voltage to provide quiet operation when system ambient temperature is low
and there are no fan failures. There is one PWM circuit for each cooling domain,
resulting in one PWM being connected to each of the two 80×38 mm fans and the other
PWM connected to the two dual-rotor 56×40 mm fans. Based on the ambient
temperature, monitored by the front panel sensor, the fan speeds (PWM duty cycle) are
set per Table 4 .
2.10.6 Cooling Summary
The four-fan cooling subsystem of the NSC2U Server is sized to provide cooling for:
• up to two server board processors
• up to 32 Gbytes of FB DIMM memory
• up to six SAS hard drives
• up to five PCI add-in cards consuming a maximum of 25W for each full-height
PCI-X/PCIe add-in cards and 10W for each low-profile PCIe add-in card
The cooling subsystem is designed to meet acoustic and thermal requirements at the
lower fan speed settings. At the higher fan speed settings, thermal requirements are
met for the maximum ambient temperatures, but acoustic requirements are not met.
Table 4. Fan Speed Settings
Temperature (°C)
CPU1 Fan
PWM DC (%)
CPU2 Fan
PWM DC (%)
PCI Fans
PWM DC (%)
0 - 28 46 46 46
29 47 47 47
30 48 48 48
31 53 53 53
32 58 58 58
33 63 63 63
34 68 68 68
35 73 73 73
36 78 78 78
37 84 84 84
38 89 89 89
39 95 95 95
40 100 100 100