Problem
Cause
Water in air
1. Contaminants in desiccant.
system
2. Leaks in air system.
Constant
1. Defective dryer outlet check valve.
exhaust of air
at air dryer
2. Dryer unloading valve not closing.
and not
Blow-Thru Type
Excessive
1. Excessive leaks in air system.
compressor
cycling
2. Defective dryer outlet check valve.
3. Undersize compressor, duty cycle of
compressor should not exceed 25%.
Safety valve
1. Desiccant cartridge is plugged.
is open
2. Ice block in dryer.
3. Excessive system pressure.
Short life of
1. Air at inlet of dryer exceeds 170°F.
dryer or
desiccant
cartridge
2. Duty cycle of compressor does not
allow for sufficient time for
desiccant regeneration.
Poor drying
1. Air at inlet of dryer exceeds 170°F.
efficiency
Troubleshooting
Repair
1. Change desiccant cartridge. Check
compressor for excessive oil passage.
2. Tighten air connections, soap
connection and recheck for leaks per
Testing the DRY est section.
1. Clean valve seat and replace
check valve.
2. At compressor cut-out there must be a
slight blow of regenerated air from the
purge tank for approximately 30
seconds. If air flow continues, replace
valve pack.
1. Tighten air connections, soap
connection and recheck for leaks.
2. Clean valve seat and replace
check valve.
3. Reduce air demand or use greater
output compressor.
1. Excessive oil passage from compressor.
Check for worn compressor. Replace
desiccant cartridge.
2. Check heater function.
3. Repair or replace governor.
1. Extend length of compressor discharge
line; see Installing the DRY est section.
The 170°F dryer inlet temperature can
usually be accomplished with 12' to 15'
of compressor discharge line.
2. During normal operation the compressor
must remain unloaded for a minimum
of 30 seconds to allow for sufficient
purge. Lengthy loading times must be
avoided. Air dryer must be "by-passed"
in applications with high air use such as
bulk unloading.
1. Extend length of compressor discharge
line; see Installing the DRY est section.
The 170°F dryer inlet temperature can
usually be accomplished with 12' to 15'
of compressor discharge line.