Troubleshooting - AEC AD Series Operation And Installation Manual

Troubleshooting

Problem
Little or no air coming from
the process delivery tube.
Suction in delivery tube,
pressure from the return tube.
Loss or reduction of process air
temperature.
Loss or reduction in drying
capacity.
AD Series Dehumidifying Dryers
Possible cause
Dirty filter.
Desiccant beds are
contaminated by material or
plasticizer leaking into the
system.
Blower overload has tripped.
Blower fins filled with dust or
contaminants.
Phase is reversed on power
drop coming into the dryer.
Process heaters are faulty.
Solid-state temperature
controller faulty.
Process temperature was
adjusted in error by plant
personnel.
Process heaters are faulty.
Desiccant beds are
contaminated.
Material being dried differs from
material specified at the time of
purchase.
Break in flex hose to/from drying
hopper.
Corrective action
Clean or replace filter.
Replace desiccant. See Section
6-5 on Page 56 for more
information.
Fix the problem and reset the
overload.
Remove blower side plate, clean
baffles, replace.
Stop the dryer.
If the dryer was connected to the
drying hopper, check to see if
the desiccant and process air
heater has been contaminated
with resin.
If so, replace the desiccant and
remove any resin carry-over.
Otherwise, change the phase of
two legs of the three-phase
power drop.
Check for open heaters.
Replace if required.
Replace.
Make sure that plant personnel
are aware of the proper
temperature set point. Post an
appropriate sign next to the
controller.
Replace.
Replace desiccant.
Drying systems are designed for
the material which was originally
specified. Different materials
may need a longer residence
time or a different drying
temperature.
Inspect for air leaks; replace as
needed.
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