Nortel North American DMS-100 Instruction Manual page 78

1-62 Trouble locating and clearing procedures (continued)
Repairing and replacing NT3X90AA cooling units
68
69
70
At the PDC frame
71
At the back of the cooling unit
72
At the front of the cooling unit
73
74
75
76
77
78
At the back of the cooling unit
79
At the PDC frame
80
At the front of the cooling unit
81
82
83
84
85
297-8021-544 Standard 14.02 May 2001
Reinstall the air intake grill and filter assembly at the at the front of the cooling
unit.
Turn OFF the FAN FAIL OVERRIDE switch on the FSP.
Go to step 86.
Remove the fuses that power the inverter cards on the cooling unit that
requires replacement.
Disconnect the plug that connects the wiring to the cooling unit.
Remove the screws that secure the side rail covers to the frame.
Remove the eight screws that secure the brackets to the sides of the cooling
unit. To remove the screws, use a 5/16-inch ratchet and extension.
Ease the cooling unit toward you and out of the frame.
Ease the replacement cooling unit into the frame.
Insert the eight screws that secure the brackets to the sides of the cooling
unit. To insert the Use a 5/16-inch ratchet and extension.
Reinstall the side rail on the front of the frame.
Reconnect the plug that connects the wiring to the cooling unit.
Reinstall the fuses that power the inverter cards.
Locate the toggle switches near the back right side of the inverter cards.
Ensure that you turn ON the toggle switches.
Reinstall the air intake grill and filter assembly at the at the front of the cooling
unit.
Turn OFF the FAN FAIL OVERRIDE switch (or switches) on the FSP (or
FSPs).
WARNING
Loss of frame cooling
Do not leave a cooling unit that has faults in the frame. If you
cannot repair the cooling unit immediately, go to step 71.
Follow the necessary parts of the procedure to replace the
unit with one that work correctly.
(continued)