Solving Problems Based On Led Behaviour; Fault Diagnosis Using Led On Outdoor Unit Pcb - Daikin 3MXM40N2V1B8 Installer's Reference Manual

15.4 Solving problems based on LED behaviour

15.4.1 Fault diagnosis using LED on outdoor unit PCB

2MXM68+3(A)MXM+3(A)MXF+4MXM+5MXM
R32 Split series
4P600463-1C – 2020.08
DANGER: RISK OF ELECTROCUTION
▪
When the unit is not operating, the LEDs on the PCB are turned off in order to
save power.
▪
Even when the LEDs are off, the terminal block and the PCB may be powered.
Symbol LED is...
On
Off
Flashing
(a)
Red LED
1 2 3 4 5
(a)
The number of LEDs displayed depends on the number of rooms.
(b)
Diagnosis may not apply to some cases. For more details, refer to the service manual.
Green LED-A
Diagnosis
Normal.
▪ Check the indoor unit.
High-pressure protector worked or freeze-up in operating
unit, or stand-by unit.
Overload relay worked or high discharge pipe
(b)
temperature.
Faulty compressor start.
Input over-current.
Thermistor or CT abnormality.
High temperature switch-box.
High temperature at inverter circuit heat sink.
(b)
Output over-current.
(b)
Refrigerant shortage.
Low voltage to main circuit or over voltage to main circuit.
Reversing solenoid valve switching failure or high-pressure
(b)
switching failure.
Faulty outdoor unit PCB.
Fan motor fault.
Wiring error
▪ Check wiring.
Diagnosis
Normal.
▪ Check the indoor unit.
15 Troubleshooting
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(b)
Installer reference guide
71