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User Guide | Optyma™ iCO2
44 | BC408445719305en-000101
© Danfoss | Climate Solutions | 2023.01 | LCA012A030
7-segment
display
Protective device symbol
Cause
Inspection
Measures / Countermeasures
E43-1
Liquid return error
Defect the anomalous under-dome
temperture
Check the specification of connected
low pressure devices
Connect the adequate low
pressure devices
Under-dome temperature sensor,
connector disconnection or short-
circuit
Replace
E45-1
Inverter-PCB transmission error
(CM1)
Loose, blown, wrong wiring
between Condensing unit-control
Wiring conductivity check Loose
connection check Wire connection No.
check
Replace wiring
Defective PCB (Condensing unit
PCB)
PCB check
Replace PCB
E48-1
DC fan motor No.1 error
Low fan speed is detected
Defective DC fan motor, connector
disconnection or short-circuit
Replace DC fan motor or PCB
E48-2
DC fan motor No.2 error
E49
Low pressure error
Low pressure is detected
Leakage of refrigerant
Repair the leakage
Defective low pressure sensor,
connector disconnection or short-
circuit
Replace low pressure sensor
E51-1
Power transistor overheat
(continue for 15 min.)
Overheat of power transistor
Check the operation of the transistor
cooling fan
Replace power transistor cooling
fan or power transistor
Stops with power transistor
temperature sensor blown wire,
output error detection
Defective power transistor temperature
sensor, connector disconnection or
short-circuit
Replace power transistor
temperature sensor
E53
Suction pipe temperature sensor
error
Suction pipe temperature sensor
blown wire, short-circuit are
detected
Suction pipe temperature sensor,
connector disconnection or short-
circuit
Replace
E54-1
Low pressure sensor error
Stops with low pressure sensor
blown wire, output error detection
Defective low pressure sensor,
connector disconnection or short-
circuit
Replace
E54-2
High pressure sensor error
Stops with high pressure sensor
blown wire, output error detection
Defective high pressure sensor,
connector disconnection or short-
circuit
Replace
E55-1
Under-dome temperature sensor
error
Under-dome temperature sensor
blown wire, short-circuit are
detected
Under-dome temperature sensor,
connector disconnection or short-
circuit
Replace
E56-1
Power transistor temperature
sensor error
Power transistor temperature
sensor blown wire, short-circuit are
detected
Power transistor temperature sensor,
connector disconnection or short-
circuit
Replace
E58-1
Rotor position detection error
Detection of the compressor rotor
position
Check the inverter output
Replace inverter or compressor
Compressor wiring, connector
disconnection or short-circuit
Replace wiring or power
transistor
E59-1
Compressor startup failure
Compressor fails to startup.
Check the inverter output
Replace inverter or compressor
Compressor wiring, connector
disconnection or short-circuit
Replace wiring or power
transistor
E60
Middle pressure sensor error
Stops with middle pressure sensor
blown wire, output error detection
Defective middle pressure sensor,
connector disconnection or short-
circuit
Replace
E63
Emergency stop
Stops with the external input
Check the connected devices
Replace wiring or repair the
connecte devices
E88-1
Oil level sensor error
The oil level of compressor is not
adequate
Check the quantity of oil with oil check
operetion
Additional refrigerant oil charge
E89
Communication error between
CPU of control PCB
Comunnication between CPU is
detected
Check the wiring surround the CPU
Repair wiring or replace PCB
Method of error inspection reset
If any error occurred, reset it as follows.
1. Remove the cause of error.
2. Adjust the 7-segment display at “P20” with SW8, SW9, and press SW7 for more than 3 seconds.
3. Change from “0” to “1” with SW8.
The error will be reset.
Make sure, however, to check the error code and remove the cause of error before resetting.
* Error cannot be reset for 3 minutes after it occurred.