3.Disable the front door switch by centering the rod and pulling outward. The secondary fan board Door LED should go Off and the Door Alarm LED at the FPU will turn green.
Fan Operation
When the cabinet is initially installed without heat generating circuit packs, the primary and secondary fans will not automatically turn On. Fan board thermostats control the On/Off fan cycle when the interior temperature reaches the thermostat’s set points.
•The primary thermostat Closes at about 110° F increasing and Opens at about 80° F decreasing.
•The secondary thermostat Closes at about 150° F increasing and Opens at about 120° F
decreasing.
•Thermostat set points may vary slightly from stated temperatures.
When the primary and secondary fan boards are initially wired and connected to the Central Office FPU, both the primary and secondary fan board thermostat (Green) LEDs should be On and the fans should be Off. This indicates that both of the fan board thermostats are Open.
If the thermostat was Closed, the thermostat LED would be Off and the fans would be On (if the temperature was within the thermostat’s Closed operating range). The thermostat LED’s operation is independent of the door switch status.
Verify Proper Connections
Test to ensure that changes to the primary fan board will cause changes to the associated LEDs at the Central Office FPU:
NOTE
This test specifies the rear door/primary fan board. Test the front door/secondary fan board by conducting a similar process.
1.Disable the rear door switch by centering the rod and pulling outward. The primary fan board Door LED should go Off.
WARNING
High voltages are present on exposed pins. DO NOT contact exposed surfaces.
2.On the primary fan board, disconnect the JP1 connector by pulling the connector out of the header. DO NOT PULL ON WIRES.
-At the Central Office FPU, the PRI FAN LED will turn red (alarm condition). This verifies the primary fan board connections are correct.
-If the PRI FAN LED at the FPU does not turn red, the connections are incorrect.
-If the secondary FPU SEC FAN LED turns on red, the circuits are crossed between the cabinet and the FPU.
3.Align and reconnect the JP1 connector.
NOTE
If the primary and secondary fan powering cable pairs are reversed at either the Central Office or at the cabinet, the primary fan will still go On at 110° F but the Central Office
FPU will indicate that the SEC FAN is running. This is an ALARM condition at the FPU.
Abnormal Condition Turning the Secondary Fan On
Any condition that causes the secondary fan to turn On is considered abnormal. The following conditions will allow heat buildup causing the secondary fan thermostat to eventually Close:
•The primary fan cannot keep up with heat load.
•The primary fan or fan board is not functioning.
•The circuitry between the FPU and the primary fan board has opened, shorted, or otherwise malfunctioned.
•The FPU at the CO is not providing power to the primary fan board.
•Additionally, the secondary fan thermostat may not be operating properly.
Fan Board Troubleshooting
If troubleshooting a fan board malfunction, fan board operation should be examined during the hottest time of the day before the outside temperature drops.
The cabinet internal temperature may stabilize slowly or quickly depending on the outside air temperature, wind conditions, exposure to the sun, shading during a particular time of day, and also the number of circuits installed inside the cabinet.
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