User guide

6
Troubleshooting
Troubleshooting l 6-7
Alarms
• Shutdown (A#): The dryer has automatically shut down because it has detect-
ed a serious problem that could damage your material or dryer.
• Passive (P#): The dryer continues to operate, but warns of a problem that could
prevent correct drying of your material. If ignored, this problem could lead to a
condition that will shut down the dryer.
Problem
A25 & P5 - Return Air Mid-
High Temperature – If the
return air temperature is
between 150 and 180°F
{66 and 82°C}. (The return
air temperature on W1600-
5000 dryers is measured at
the inlet to the desiccant
wheel. W1600-5000 dryers
designed prior to August
2007, the return air tempera-
ture is measured at the inlet
to the process blower.)
A26 & P6 - Regeneration
High Temperature – If the
regeneration temperature
exceeds the high temperature
limit for the specified time.
Default values are 400°F
{204°C} for 20 seconds
A27 & P7 - Regeneration
Low Temperature – The
regeneration temperature is
less than the low temperature
for the specified time (200°F
{93°C} for 20 seconds).
Possible cause
The hopper does not contain enough
material.
You are drying at a high drying tempera-
ture above 120°F {49°C} or running at
low throughputs.
The aftercooler/intercooler does not have
enough water.
The aftercooler/intercooler coils are
dirty.
One of the solid state relays (SSRs)
failed in the closed position.
The output on the board has failed.
The regeneration heater has failed.
The output on the control board has
failed or the fuse has blown.
The regeneration RTD is loose or has
fallen out.
Solution
Make sure your material supply system
is working properly.
Ensure water flow to the aftercooler/
intercooler.
Turn on the water supply, or fix any
leaks or blockages.
Clean the aftercooler/intercooler coils.
See Maintenance section entitled,
Cleaning the aftercooler/intercooler
coils.
Replace the failed solid state relays
(SSRs).
Replace the board.
Check the heater fuses, and resistance
across each leg of the regeneration
heater.
Replace the control board or the fuse.
Check the regeneration RTD and tighten
if needed.