Chapter 6: Troubleshooting
6-1 Introduction
The utmost in safety precautions should be observed at all times when working on or around
the machine and the electrical components. All normal trouble-shooting must be
accomplished with the power off, line fuses removed, and with the machine tagged as out of
service.
The use of good quality test equipment cannot be over-emphasized when troubleshooting is
indicated. Use a good ammeter that can measure at least twice the AC and DC current that
can be encountered for the machine. Be sure that the voltmeter has at least minimum
impedance of 5,000 OHMS-per-volt on AC and 20,000 OHMS-per-volt on DC scales.
Popular combination meters, VOM and VTVM can be selected to provide the necessary
functions.
Before making haphazard substitutions and repairs when defective electrical components are
malfunctioning, we recommend that you check the associated circuitry and assemblies for
other defective devices. It is common to replace the obviously damaged component without
actually locating the real cause of the trouble. Such hasty substitutions will only destroy the
new component. Refer to wiring diagrams and schematics.
Locating mechanical problems, should they occur, is relatively straightforward. When
necessary, refer to the parts catalog section.
Alarm Message Cause Corrective Action Dryer Status
VALVE
POSITION
FAULT
The limit switch on the
valve may not have
been wired correctly.
The switch is indicating the
incorrect desiccant tank is in
regeneration. Check the
wiring of the switch against
the wiring diagram. Make
sure all the wire connections
are tight.
- Dryer Shuts down:
- Process blower OFF.
- Process heaters OFF.
- Regen heaters OFF.
- Alarm light is ON
- Alarm horn is ON.
Limit switch may be out of
position. Re-adjust the
switch to make sure it trips
when it is at the high
position, and it does not
touch the cam when it is at
the low position.
VALVE MOTOR
OVERIDE
The valve has made
enough rotations and
the correct position of
the valve was not
detected.
Limit switch may be faulty.
Replace the switch and
make sure the wires are
connected correctly.
- Dryer Shuts down:
- Process blower OFF.
- Process heaters OFF.
- Regen heaters OFF.
- Alarm light is ON
- Alarm horn is ON.
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