AEC WD 350 through WD3000 Dehumidifying Dryers - Manual (Page 73)

8 Troubleshooting
Problem Possible cause Corrective action
Dirty filter. Clean or replace filter.
Desiccant beds are
contaminated by material or
plasticizer leaking into the
system.
Replace desiccant. See
Section 7-5 on Page 51 for
more information.
Blower overload has tripped.
Fix the problem and reset the
overload.
Little or no air coming from
the process delivery tube.
Blower fins filled with dust or
contaminants.
Remove blower side plate,
clean baffles, replace.
Suction in delivery tube,
pressure from the return
tube.
Phase is reversed on power
drop coming into the dryer.
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.
Process heaters are faulty.
Check for open heaters.
Replace if required.
Solid-state temperature
controller faulty.
Replace.
Loss or reduction of process
air temperature.
Process temperature was
adjusted in error by plant
personnel.
Make sure that plant
personnel are aware of the
proper temperature set point.
Post an appropriate sign next
to the controller.
Process heaters are faulty. Replace.
Desiccant beds are
contaminated.
Replace desiccant.
Material being dried differs
from material specified at the
time of purchase.
Drying systems are designed
for the material which was
originally specified. Different
materials may need a longer
residence time or a different
drying temperature.
Loss or reduction in drying
capacity.
Break in flex hose to/from
drying hopper. Inspect for air leaks; replace
as needed.
Page 72 WDMR and WDFR Series Dehumidifying Dryers