Nortel North American DMS-100 Instruction Manual page 76

1-60 Trouble locating and clearing procedures (continued)
Repairing and replacing NT3X90AA cooling units
41
At the FSPs
42
43
44
45
46
47
48
297-8021-544 Standard 14.02 May 2001
WARNING
Incorrect fuse values
Use replacement fuses of the correct rating, or damage to the
equipment may result.
Replace the fuses in the PDC. Replace the blown fuse with a new fuse.
If FAN FAIL lamps at the FSPs
are dark
are lit
Turn OFF the FAN FAIL OVERRIDE switches.
Go to step 86.
Remove the air intake grill and filter assembly from the front of both cooling
units.
Inspect the fans in both cooling units.
If
a complete row of fans do not
work in each cooling unit
other than listed here
Locate the toggle switches at the back right corner of each inverter.
Note: The toggle switches are the ON/OFF power switches for the
inverters.
Cycle the toggle switches on both inverters to find the inverter that powers the
rows of fans that do not work.
If company procedures
direct you to do repairs
do not direct you to do repairs
Note: Each inverter powers the row of three fans. The front of the cooling
unit houses the row of fans. Each inverter also powers the row of two fans
at the back of the paired unit.
Identify the cooling unit with the inverter that powers the fans that do not
operate. Replace this cooling unit.
(continued)
Do
step 42
step 44
Do
step 46
step 85
Do
step 50
step 48