TROUBLESHOOTING
Table 1 — Troubleshooting Guide for PH Series Heatless Regenerative Dryers
Symptoms
Cause
Remedy
A. Elevated Dewpoint.
1. Low purge flow.
2. Low inlet pressure.
3. Excess moisture carryover.
4. High inlet temperature.
5. Excess air/gas inlet flow.
6. Desiccant coated with oil.
7. Regeneration temperature low.
8. Dewpoint monitor out of calibration.
1. Reset purge pressure at the
recommended pressure.
2. Recalculate purge pressure
setting from the chart.
3. Check prefilter element. Check
drains at prefilter and afterfilter.
4. Check aftercooler operation.
5. Check total output of
compressors.
6. Depressurize dryer and inspect
desiccant.
7. *See
B.
8. Recalibrate
probe.
B. High back pressure on
regenerating tower.
NOTE:
The tower should be at ‘0’
PSIG during regeneration cycle. Any
back pressure will result in improper
regeneration.
1. Muffler plugged.
2. Check valves leaking.
NOTE:
To test for leaking check
valves during regeneration cycle, shut
the purge adjusting valve. If gas is still
passing through, it is an indication of
leaking check valves.
3. Excess purge flow.
4. Restricted purge exhaust piping.
5. Too high purge.
1. Replace
mufflers.
2. Repair or replace faulty check
valves.
3. Check and reset the purge
pressure.
4. Remove obstruction or replace
with larger size pipe.
5. Check purge calibration, plot and
reset.
C. Excessive flow through mufflers.
1. Check valves leaking.
NOTE:
To test for leaking, check
valves during regeneration cycle, shut
the purge adjusting valve. If gas is still
passing through, it is an indication of
leaking check valves.
2. Inlet valves did not switch.
3. Purge valve stays open.
4. Repressurizing valve does not
close.
1. Repair or replace faulty check
valves.
2. See E1 to E4.
3. Check purge solenoid and valve.
Repair or replace faulty purge
valve or solenoid.
4. Check repressurizing solenoid
and valve. Repair or replace faulty
repressurizing valve or solenoid.
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