Alpha Technologies FBE2322 Enclosure System - Manual (Page 33)

33 031-314-B0-001, Rev. A (12/2012)
3.0 Environmental Control Systems, continued
3.4 FBE2322 Heat Exchanger
General Operation:
The heat exchanger moves the heated cabinet air into a network of closed loop vents that are in close
contact with closed loop vents with ambient air passing through them. This process transfers heat out of
the cabinet maintaining a constant internal temperature.
Features:
• Programmable variable speed DC fan controller with self-test.
• Internal fan: Off below 5ºC. On at 10ºC min speed; Variable to max speed between 20ºC to 35ºC.
• External Fan: Off below 15ºC. On at 20C min speed; Variable to max speed between 30ºC to 45ºC.
• High Temp alarm: 70ºC.
• Low Temp Alarm: -50ºC.
• Fan fail: Alarm contact loop open on alarm.
3.5 FBE2322 Emergency Fan
General Operation
When the primary cooling system cannot maintain adequate enclosure temperature, the emergency fan
thermostat closes energizing the emergency fan relay. This activates the form C dry contact alarm. The
high temperature alarm activates, the emergency air dampers open and the emergency fans turn on. Fan
air pressure pushes open the discharge air check valves and an electronic solenoid opens the air intake
damper.
Features:
• Two 118 CFM fans are powered by a variable speed temperature control. Fans turn off below
25ºC. Fans turn on at 25ºC and increase from 50% to 100% full speed with increased enclosure
temperature from 25ºC to 45ºC.
• Dual Fan Control PCBA has a green LED to indicate proper function, a red LED to indicate an alarm
condition and a push button test feature. During the test fans momentarily ramp up to full speed and
the alarm condition will be indicated. After this test sequence the fans will return to normal speed and
the alarm will clear with green LED indicated. Emergency fan solenoid does not have low voltage
disconnect (LVD) protection.
• One form C dry contact alarm, open on alarm.
Emergency Fan System Power Requirement:
• 24 or 48VDC input power.
• 3A fuse or circuit breaker is required (not provided unless configured with Cordex shelf or GMT fuse
panel options).
• 20awg input power leads provided (see wire labels for correct voltage and polarity).
• Maximum power draw 36W.