Service manual: TAC-12D-10
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● LED status indication
The WORK LED light at the left side of the screen is used as working indicator lights,
flashing is to indicate the delay of cooling; if the LED is always on, it indicates it is on the
state of cooling or heating;
The SET LED light at the left side of the screen is used as setting indicator lights, if the
LED is always on, it indicates it is on the state of setting.
● Door limit switch
If a door limit switch is used and the cabinet door is open (contact is closed when door is
open), the cooling unit (external fan and compressor) will switch off after approx 5 s,
thereby avoiding an increase in condensation while the door is open. To avoid cyclic
operation, switch on of compressor and external fan is delayed by about 3 minutes after
the door has been closed.
● Alarm output
The air conditioner is permanently controlled by the microcontroller. Faults which can
occur are registered and will be passed on the LED display panel, also the dry contact
alarm.
Alarm code and system message
Alarm code System message
E1 Internal temperature exceeds P4
E2 Internal temperature below P5
E3 Evaporator freezing
E4 High/low 220VAC power supply
E5 Condenser high pressure
E6 Internal temperature sensor failure
E7 Evaporator temperature sensor failure
E8 Door open
The dry contact alarm is triggered if any of the above alarm is detected.
The dry contact alarm functions as follows:
Storage conditions: Open contact
Operation: Closed contact
Alarm: Open contact
The maximum load of dry contact is:
Resistive load 3A@250VAC or 3A@30VDC