Dyer Manual

62
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 working
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 obstructions
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 qualified 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 l iquid 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 experienc ed ref rigeration 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 technician.
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 needed. 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.