User Guide | Optyma™ control AK-RC 111 single phase
© Danfoss | DCS (vt) | 2020.03 BC309238530328en-000101 | 13
6.0 Troubleshooting In the event of any anomalies of the AK-RC 111, it notifies the operator by means of the alarm codes 
displayed on the display and an audible signal emitted by a buzzer inside the control panel. The EL 
and EH temperature alarms remain visible even after their return (alarm icon lights on) until their 
acknowledgment (by pressing the key). If an alarm condition occurs, one of the following messages 
will be displayed on the display:
Alarm code Possible cause Solution
E0 Cold room temperature sensor not working properly •  Check that cold room temperature 
sensor is working properly
•  If the problem persists, replace the 
sensor
E1 Defrost sensor not working properly
(In this case defrosts will last time d3)
•  Check that defrost sensor is 
working properly
•  If the problems persists, replace the 
sensor
E2 Eeprom alarm
An EEPROM memory alarm has been detected
(All outputs except the alarm one are deactivated)
•  Switch unit off and back on 
E8 Man in cold room alarm •  Reset the alarm input inside the 
cold room
Ec Compressor protection tripped
(e.g. thermal protection or max pressure switch)
(All outputs except the alarm one – where applicable – 
are deactivated)
•  Check that compressor is working 
properly
•  Check compressor absorption
•  If the problem persists, contact the 
technical assistance service
Ed Open door Alarm.
When the door is opened and after tdo time, it’s setted 
back the normal functioning giving door open alarm 
(Ed).
•  Check door switch status 
•  Check door switch connections
•  If the problem persists contact the 
technical assistance service
E9 Cell light alarm.
The light of the cell has been on for a time greater than 
tdo.
•  Turn off the light
EH Maximum temperature alarm.
The temperature inside the cold room has exceeded 
the max. temperature alarm setting (see variables A2, 
user programming level)
•  Check that the compressor is 
working properly.
•  Sensor not reading temperature 
properly or compressor start/stop 
control not working.
EL Minimum temperature alarm.
The temperature inside the cold room has exceeded 
the min. temperature alarm setting (see variables A1, 
user programming level).
•  Check that the compressor is 
working properly.
•  Sensor not reading temperature 
properly or compressor start/stop 
control not working.