Technical information

PLC C
ONTROL
ALARM
CONDITIONS
Possible cause
No or low flow with a
failed flow switch and
RTD.
Compressor suction valve
is closed.
The Evaporator is fouled.
Evaporator frozen.
Faulty TXV solenoid.
Refrigerant leak.
Faulty pressure transduc-
er.
Condenser air or water
too cold.
Wiring incorrect.
Solution
Check To Process and From Process
valves to see if they are open. Check
Flow switch and RTD. Replace as
needed.
Open valve.
Clean Evaporator. See Cleaning the
Evaporator or Water-cooled Condenser,
in the Maintenance section.
p Check flow switch, RTD, tempera-
ture transmitter and low temperature
cutout on temperature controller.
Replace as needed.
p Check PLC control for proper per-
cent ethylene glycol or propylene
glycol solution. Change percent gly-
col setpoint, if needed. Add glycol if
needed.
Check wiring, voltage, coil and relay
(see electrical drawings); replace as
needed.
Check for oil in chiller cabinet and
bubbles in refrigerant sight glass.
Consult Conair Service for repair.
See Checking the Pressure Transducer,
in the Troubleshooting section.
Check air/water temperature. Water
should be 65 F or higher; air tempera-
ture should be 60 F or higher.
Use wiring diagrams and check wiring.
Correct as needed.
UGH024/1103 Portable Chillers
TROUBLESHOOTING
6-41
Alarm
Low Suction
Pressure 2 alarm