Page
61
Problem
Possible Cause
Repair
Comments
Water in system
Compressed Air Inlet and
outlet connections are
reversed.
Check inlet and outlet
connections.
This dryer is designed for air flow in one direction only. Inlet and
outlet directions are identified on the dryer.
Drain system is clogged
or inoperative.
Restore a free flow of
water condensate. Check
water evacuation.
Drain system is timed solenoid valve, pneumatically assisted which
has to be adjusted in accordance with values listed in this
manual. The Solenoid valve includes a strainer that has to be
periodically checked and cleaned. Membranes of pneumatically
assisted drain have to be checked or replaced every 6 months.
Bypass system is open
Check the valves
Important: Bypass piping should be installed around the
dryer so the dryer can be isolated for service without
shutting down the air supply. During dryer operation, valves
must be set so all air goes into the system. Check tightness of the
bypass system.
Free moisture remains in pipe
lines.
Blow out the system
Before the dryer is first started all free moisture should be
blown out of the system.
Excessive air flow
Check actual flow
through the dryer.
This dryer is designed for a maximum air flow. If too much air is
pumped into the dryer, water removal capacity may not be
sufficient, resultingin liquid Carry over downstream. Check the
rated flow of the air compressor .
Excessive free moisture
Check the separator and
drain system and
compressor after cooler
ahead of the dryer.
In some system there may be an accumulation of free moisture in
the line ahead of the dryer. If this moisture is pumped into the
dryer intermittently, the water removal capacity may not be
sufficient. A water separator should be installed in the line
before the dryer.
Excessive compressed
air inlet temperature.
Be sure that dryer is wor-
king lower than design
conditions
The dryer is designed to work for calculated design conditions.
Should the conditions be exceeded, the dryer will be overflowed,
dew point will go up and protecting devices can switch off.
Clogged condenser fins
Clear fins of all obstru-
ctions
The clogged fins in the condenser will restrict air passage and
reduce refrigerant capacity causing water downstream. Fins
should be periodically checked and cleaned.
Shortage of refrigerant
Fix the leak and add a
charge of refrigerant.
Loss of refrigerant will cause improper functioning. A qualified,
refrigeration specialist should perform the necessary repairs, or
factory should be contacted if the unit is in warranty.
Refrigeration system is
not functioning
Check to be certain
refrigerant
compressor is running
To check if the compressor is running, check compressor-on light.
lt is possible for the fan to be operating but not the compressor.
Compressor not running can be caused by several taeters.
A qualified refrigeration technician should check all refrigerant and
electrical controls
Excessive pressure dew point
Readjust refrigerant
evaporating pressure
The refrigerant pressure adjustment should be done by a qu-
alified refrigeration engineer. This is a very sensitiye device and
incorrect settings may create other failures.
High
pressure
drop
Excessive compressed
air flow or too law air inlet
pressure.
Check actual pressure and
flow through the dryer.
This dryer is designed for a maximum air flow. If too much air
is pumped into the dryer, water removal capacity may not be
sufficient, resulting in liquid carry-over downstream.
Check the rated flow of the air compressor.
Freeze up
Check that compressor
room
ambient,
Frosting of the Iines is an indication that controls are set too low.
The following should be done by an experienced
refrigeration technician.
Fan switch could have
failed in closed position
keeping fan on.
Controls may be adjusted in the fields by means of the hot gas
bypass valve. This is to be done by a qualified refrigerant tech-
nician.
The unit will not
run or cycles off
and on.
Clogged heat exchanger
Clean heat exchanger
with areverse air flow.
Dryer are supposed to be used with compressed air free of any
aggressive contaminants. Some contamination may require extra
maintenance of the heat exchanger.
Line disconnect switch is
open.
Close the start or
disconnect switch.
If the dryer is not operating, check the disconnect switch or circuit
breaker to be certain it is on.
Fuse or breaker is open
Replace fuse or reset
breaker.
The fuse to the power line should be checked and replaced if nee-
ded. Never replace a burnt fuse with an oversized fuse.
Faulty refrigerant
compressor or controls.
Determine the cause and
make
correction
Failure of compressor to run may be caused by several
factors. A qualified refrigeration specialist should check all
electrical and refrigeration controls, or factory should be
contacted if unit is in warranty.
Excessive compressed air
inlet temperature.
Design conditions and
correction
factors are described in
this manual.
Be sure that dryer is
working
in ambient temperatures
below design conditions.
The dryer is designed for working into calculated design
conditions. Should the conditions be exceeded, the dryer will be
overflowed, dew point will go up and protecting devices may trip.