1-70 Trouble locating and clearing procedures (continued)
297-8021-544 Standard 14.02 May 2001
Repairing and replacing NT3X90AB cooling units
(continued)
19
Cycle the toggle switches on both inverters until you find the inverter that
powers the row of fans that have faults.
20
Switch OFF the inverter that provides power to the row of fans that have
faults.
At the PDC frame
21
Remove the fuse for the damaged inverter.
At the frame
22
Disconnect the connector at the back left corner of the inverter.
23
Use a pair of needle-nosed pliers to disconnect the four plastic mounting pins.
24
Lift the old inverter out of the cooling unit. Replace the old inverter with a new
inverter.
25
Mount the new inverter on the four plastic mounting pins.
26
Plug the connector into the back left corner of the inverter.
At the PDC frame
27
Examine the fuse to the inverter. If the fuse is a blown fuse, obtain a new fuse.
Replace the fuse in the PDC.
At the frame
28
Turn ON the toggle switch of the new inverter.
29
To turn OFF the inverters, use the toggle switches at the back right corner of
the inverters.
30
Inspect the cooling unit wiring harness for damage and/or a loose connection
at the fans or terminal blocks.
31
Replace a defective harness. Tighten any loose connections.
32
To turn ON the inverters, use the toggle switches at the back right corner of
the inverters.
33
Inspect the fan operation.
If
Do
the fans work normally and the
FAN FAIL lamp does not turn
on
step 55
other than listed here
step 78
If the fan
Do
works correctly, but did not
work in step 17
step 55
