Nortel North American DMS-100 Instruction Manual page 60

1-44 Trouble locating and clearing procedures (continued)
Repairing FAN faults on an LCEI frame;
cooling unit replacement
32
At the front of the cooling unit
33
34
35
36
37
38
39
40
41
42
43
297-8021-544 Standard 14.02 May 2001
(continued)
Determine if any of the front three fans decreased in speed or failed.
If
one or more damaged fans are
present
no damaged fans are present
Note: Determine if all fans run, and the FAN FAIL lamp on the front of the
cooling unit is on. If the fans run, and the FAN FAIL lamp is on, the
problem can be a defective air flow sensor switch.
Remove the fuse associated with the defective fan from the front panel.
Disconnect the power supply wiring to the defective fan.
Note the position of the sensor switch on the defective fan.
Remove the four screws that secure the fan and the screw that secures the
sensor switch.
Mount the new fan. Position the fan so that air flows toward the top, as the
fan label indicates.
Replace the sensor switch. Secure the switch with the mounting screw.
Connect the power supply to the new fan.
Replace the fuse that you removed in step 33.
If necessary, repeat steps 33 to 40 for other damaged fans.
If the FAN FAIL lamp
is off
is on
Inspect the sails of the air flow sensors. Adjust or replace any sails that
appear defective.
If the FAN FAIL lamp
turns off
remains on
Disconnect the wiring from one of the sensor switches. Note which wire
connects to each terminal.
If the FAN FAIL lamp
turns off
Do
step 33
step 42
Do
step 48
step 42
Do
step 48
step 42
Do
step 44