Liebert Rack Enclosure With Integrated Water-Based Cooling XDK - Manual (Page 10)

Description
6
3.3 Control
The server cabinet temperature is controlled by the fan control board
A temperature sensor continuously measures the temperature of the server cabinet (server feed air).
The air circulation flow rate is controlled by the fan speed according to the current thermal load.
At temperatures lower than 70°F (21°C) fans rotate at 75% of maximum speed.
Between 68°F and 73°F (20 and 23°C), speed increases proportionally to the temperature up to 96% of
maximum speed.
The failure of the temperature sensor set the fans to maximum speed.
The water flow rate is controlled by a three-way valve depending on thermal load. In case of failure,
the valve opens and the all the chilled water flows through the heat exchanger.
From 61°F to 66°F (16°C to 19°C), the three-way valve controls the water flow rate from 0% to 100% of
the nominal flow rate.
The programming of the control is factory-set and protected with a password.
The failure of the temperature sensor or one of the fans will set off an alarm using a potential free
contact.
The outgoing alarms with potential free contact are:
• sensor error
• fan malfunction
• high-temperature / low-temperature
The fans are automatically shut down if the server cabinet rear door is opened.
3.4 Automatic Door Opening
Figure 3 XDK door and automatic opening mechanism
Upper magnet
and retaining
plate
Gas pressure spring