Nortel North American DMS-100 Instruction Manual page 70

1-54 Trouble locating and clearing procedures (continued)
Repairing and replacing NT3X90AA cooling units
Repairing and replacing NT3X90AA cooling units
At the FSP
1
2
At the frame
3
4
5
6
7
8
297-8021-544 Standard 14.02 May 2001
The cooling unit configuration in the frame can differ from the following
description. If you encounter an important difference, contact your next level
of support.
Identify the frame, or the pair of frames, where the lit FAN FAIL lamp is on the
Frame Supervisory Panel (FSP).
Note: NT3X90AA power supplies for the cooling unit connect in pairs. A
problem in one unit on a pair can cause an interruption in the operation of
both units of the pair. Frames that are near each other will house the pairs.
To silence the alarm, turn ON the FAN FAIL OVERRIDE switch (or switches).
If the lit FAN FAIL lamp
is on only one frame
is on two frames
Remove the air intake grill and filter assembly from the front of the affected
cooling unit.
Determine if the FAN FAIL lamp darkened on the Frame Supervisory Panel
(FSP) when you removed the filter.
If the FAN FAIL lamp
darkened
remained on
Remove the filter and intake grill to a location away from the switchroom. To
clean the fan air intake, use a dust cloth and vacuum.
Vacuum or wash the filter in soap and water, according to the filter type.
Replace the filter in the grill and reinstall the grill at the front of the cooling unit.
Turn OFF the FAN FAIL OVERRIDE switch.
Go to step vr.
If your company procedures
direct you to do repairs
(continued)
ATTENTION
Do
step 3
step 39
Do
step 5
step 8
Do
step 9