morse AHT 20 Manuel D'instructions page 25

Only qualified personnel should perform troubleshooting and or maintenance operations.
Prior to performing any maintenance or service, be sure that:
• no part of the machine is powered and that it cannot be connected to the mains supply.
• no part of the machine is under pressure and that it cannot be connected to the compressed air
system.
• Maintenance personnel have read and understand the safety and operation instructions in this
manual.
Before attempting any maintenance operation on the dryer, shut it down and wait at least 30
minutes.
Some components can reach high temperature during operation. Avoid contact until system or
component has dissipated heat.
SYMPTOM
The dryer doesn't
start.
The compressor
doesn't work.
The fan of the
condenser doesn't
work.
AHT 75-350- The
Aftercooler fan
doesn't work.
DewPoint too high.
6.2 TROUBLESHOOTING
POSSIBLE CAUSE - SUGGESTED ACTION
Verify that the system is powered.
Verify the electric wiring.
Activation of the compressor internal thermal protection - wait for 30 minutes, then
retry.
Verify the electric wiring.
Where installed- Replace the internal thermal protection and/or the start-up relay
and/or the start-up capacitor and/or the working capacitor.
Where installed- The pressure switch P
Where installed- The pressure switch P
Where installed- The safety thermo-switch T
If the compressor still doesn't work, replace it.
Verify the electric wiring.
P pressure switch is faulty - replace it.
V
There is a leak in the refrigerating fluid circuit - contact a refrigeration engineer.
If the fan still doesn't work, replace it.
Verify the electric wiring.
If the fan still doesn't work, replace it.
The dryer doesn't start - see specific point.
The T1 DewPoint probe doesn't correctly detect the temperature - ensure the
sensor is pushed into the bottom of copper tube immersion well.
The refrigerating compressor doesn't work - see specific point.
The ambient temperature is too high or the room aeration is insufficient - provide
proper ventilation.
The inlet air is too hot - restore the nominal conditions.
The inlet air pressure is too low - restore the nominal conditions.
The inlet air flow rate is higher than the rate of the dryer - reduce the flow rate -
restore the normal conditions.
The condenser is dirty - clean it.
The aftercooler is dirty - clean it.
The condenser fan doesn't work - see specific point.
The aftercooler fan doesn't work - see specific point.
The dryer doesn't drain the condensate - see specific point.
The hot gas by-pass valve is out of setting - contact a refrigeration engineer to
restore the nominal setting.
There is a leak in the refrigerating fluid circuit - contact a refrigeration engineer.
has been activated - see specific point.
A
has been activated - see specific point.
B
has been activated - see specific point.
S
GB