Trouble locating and clearing procedures (continued) 1-49
DMS-100 Family NA100 Trouble Locating and Clearing Procedures Volume 2 of 2 LET0015 and up
Repairing an NTBX63AA cooling unit on the bench top
(continued)
6
Disconnect the power supply.
7
Replace or repair the harness that has faults. Tighten the loose connections.
8
Reconnect the 48 V dc power supply.
9
Inspect the fan operation.
10
Note the fans that do not work correctly.
11
Disconnect the power supply.
12
Disconnect the power supply wiring to the fan (or fans) that has faults noted
in step 10.
13
Note the position of the sensor switch on the fan that has faults.
14
Remove the four screws that secure the fan and the screw that secures the
sensor switch.
15
Mount the new fan so that air flows toward the top, as indicated on the label.
16
Replace the sensor switch of the last installation. Secure the sensor with the
mounting screw.
17
Reconnect the power supply to the new fan.
18
If necessary, repeat steps 12 to 17 for other fans that havew faults.
19
Turn ON the power switch on the unit.
20
Inspect the fan operation.
21
Inspect the sensor sails and adjust or replace any sails that appear to have
faults.
22
Disconnect the wiring from one of the sensor switches. Note which wire
connects to each terminal.
23
Connect an ohm meter to the two connected terminals of the sensor switch.
24
Lift the sail of the air flow sensor.
25
An ohm meter that has a closed circuit with the sail in the up position indicates
a sensor has faults. Note the sensor and go to step 27.
If the fans
Do
work correctly
step 35
do not work correctly
step 10
If the fans
Do
work correctly
step 35
do not work correctly
step 34
If the ohm meter
Do
indicates a closed sensor switch
step 25
indicates an open sensor switch
step 26