Air conditioning module alarms, troubleshooting and upkeep

Alarms

All alarms reset automatically once the cause is gone.

Alarm	Condition	Reset	Dry contact output
High temperature	Cabinet temperature is above the setting	Automatic	Yes
Low temperature	Cabinet temperature is below the setting	Automatic	No
T1 temperature sensor	Short or open circuit on the cabinet temperature sensor cable	Automatic	No
T2 temperature sensor	Short or open circuit on the evaporator temperature sensor cable	Automatic	No
T3 temperature sensor	Short or open circuit on the condenser temperature sensor cable	Automatic	No
Evaporator frozen	Evaporator temperature is below 0 °C	Automatic	Yes
Frequent high system pressure	System pressure frequently exceeds the setting	Automatic	Yes
Controller power failure	No power input to the controller	Automatic	Yes

Faults and fixes

Temperature sensor failure

Possible cause	Fix
Sensor not connected correctly	Check the connectors and reconnect the sensor
Sensor damaged	Replace the sensor

High temperature alarm

Possible cause	Fix
Condenser or evaporator dirty and blocked	Clean the condenser or evaporator
Insufficient cooling capacity	Consult a specialist
Wrong temperature setting	Set the temperature again

Frequent high system pressure alarm

Possible cause	Fix
Condenser or evaporator dirty and blocked	Clean the condenser or evaporator
External fan faulty	Replace the fan
Condenser temperature sensor sends false alarms	Replace the condenser temperature sensor

Evaporator frozen alarm

Possible cause	Fix
Internal air path blocked	Check for obstructions in the internal air path
Internal fan faulty	Repair or replace the fan
Cooling system does not stop	Check whether the unit reached the cooling stop conditions but keeps cooling; if so, inform the manufacturer
Evaporator temperature sensor sends false alarms	Replace the temperature sensor

Compressor does not run

Possible cause	Fix
No cooling demand	Check whether cooling is actually needed
Shutdown delay active	Check whether compressor protection is active
Compressor cable not connected correctly	Check the compressor cable and reconnect it
Compressor protection switch or motor faulty	Check the protection switch and replace it if faulty; if the motor is faulty, replace the compressor

Internal fan does not run

Possible cause	Fix
Internal fan faulty	Replace the fan
Internal fan cable not connected correctly	Check the cable and reconnect it
Fan stuck	Check for anything blocking the fan and clear it

External fan does not run

Possible cause	Fix
External fan faulty	Replace the external fan
Operating condition not met	Check whether the operating condition is met
External fan cable not connected correctly	Check the cable and reconnect it
External fan stuck	Check for anything blocking the fan and clear it

Fan makes abnormal noise

Possible cause	Fix
Blades damaged or bearing worn	Replace the damaged fan
Blades touch other objects	Check and refit the fan

Heater does not run

Possible cause	Fix
Heater faulty	Replace the heater
Heater cables not connected correctly	Check the heater cables and reconnect them
Operating condition not met	Check whether the operating condition is met

Periodic maintenance

Careful maintenance keeps the unit performing well and preserves its normal service life. Carry out the following:

No.	Check / maintenance	Interval
1	Check for alarms	6 months
2	Check that the fans rotate normally	6 months
3	Check that the compressor runs normally	6 months
4	Check for obvious noise or vibration	6 months
5	Clean the internal and external air inlets and outlets	6 months
6	Clean the heat exchangers	1 year
7	Check the power supply and communication cables	1 year

If the problem persists after these checks, contact the support team.

Alarms