Daikin Ducted Type Indoor Unit FDMG48NUV2S

As criteria for judging whether refrigerant is excessively charged or not, refer to the following operating conditions.

<Diagnosis of excessive refrigerant charging>

(1) Because high pressure rises due to excessive charging, overload control is carried out and capacity tends to run short.

(2) Considering pressure load, compressor discharge pipe temperature is low.

(3) Subcooling degree of condensate liquid becomes large. Therefore, temperature of blown air passing through subcooling part decreases in heating operation.;

Warning: High pressure checks should be performed by trained personnel only

Enter the current pressure level

Is the pressure level above the normal range?

If pressure is above normal, proceed with the following checks

List the issues found during the condenser side check

Sign off on the high pressure check

Warning: Disconnect the thermistor from the PCB before proceeding

Thermistor disconnected from the PCB

Upload a photo of the table with the measured values

Check if the measured values correspond with the values in the table

Sign off on the thermistor check

Diagnosis of inadequate refrigerant in cooling operation

Suction superheated degree increases due to refrigerant shortage

Decreased evaporator capacity caused by refrigerant shortage

Compressor frequency decreases despite a large difference between temperature set by the remote controller and suction air temperature

Electronic expansion valve remains fully open and suction superheated degree further increases

Diagnosis of inadequate refrigerant in heating operation

Suction superheated degree increases due to refrigerant shortage

Compressor frequency decreases because suction superheated degree is controlled to prevent oil to the outdoor unit heat exchanger from being retained

Evaporator capacity and compressor frequency decrease despite a large difference between temperature set by the remote controller and suction air temperature

Procedure for checking outdoor-outdoor unit transmission wiring for broken wires

Turn OFF the power supply to all equipment

Short circuit between the outdoor-outdoor unit terminal F1 and F2 in the 'Outdoor Unit A'

Conduct continuity checks between the transmission wiring terminal blocks F1 and F2 of the centralized remote controller using a multiple meter

Is there continuity between the said terminal blocks?

If there is no continuity, the transmission wiring may have broken wires

With the outdoor-outdoor unit terminal of the 'Outdoor Unit A' short circuited, conduct continuity checks between the transmission wiring terminal blocks F1 and F2 of the unified ON/OFF controller

Procedure for checking indoor-outdoor unit transmission wiring for broken wires

Turn OFF the power supply to all equipment