Nortel North American DMS-100 Instruction Manual page 82

1-66 Trouble locating and clearing procedures (continued)
Repairing and replacing NT3X90AB cooling units
Repairing and replacing NT3X90AB cooling units
At the FSP
1
At the frame
2
3
4
5
6
7
8
At the PDC frame
9
297-8021-544 Standard 14.02 May 2001
DANGER
Next level of support
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.
To silence the alarm, turn ON the FAN FAIL OVERRIDE switch.
Remove the air intake grill and filter assembly from the front of the 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 grill to a location away from the switchroom. Use a dust
cloth and vacuum to clean the fan air intake.
Vacuum or wash the filter in soap and water, according to the filter type.
Replace the filter in the grill and reinstall the filter in the cooling unit.
Turn OFF the FAN FAIL OVERRIDE switch.
Go to step 79.
DANGER
Possible arcing
Electricity can arc when you remove cooling unit fuses. Wear
eye protection.
Remove the fuses that power the inverters.
(continued)
Do
step 4
step 9