Daikin Outdoor Unit For Reverse Cycle System RY100KUY1

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.;

Check for Fan Motor Connector (Signal Line)

(2) With the fan motor connector disconnected, measure the resistance between each pin, then make sure that the resistance is more than the value mentioned in the following table.

(2) With the fan motor connector disconnected, measure the resistance between each pin, then make sure that the resistance is balanced in ±30%.

Check for Fan Motor Connector (Power Supply Line)

With the relay connector disconnected, measure the resistance between UVW phases of the connector (3 cores) at the motor side, then make sure that the resistance between each phase is balanced and not short-circuited.;

Warning: Do not touch the energized part (high voltage part) for at least 10 minutes after the power is turned OFF.

Be sure to touch the earth terminal with a hand to release static electricity from the body (to prevent PCB from being damaged).

Residual electric charge of the power transistor (should be DC 50V or less)

Remove the connector of the outdoor unit fan motor.

Remove the wire connecting the power transistor and the compressor. Remove it from the compressor terminal side.

During this work, be careful not to deform. Faston terminal at the end of the relay wire.

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

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

<Diagnosis of inadequate refrigerant>

(1) As suction superheated degree increases due to refrigerant shortage, the electronic expansion valve tends to open (opens fully) in order to avoid overheat operation.

(2) In response to decreased evaporator capacity caused by refrigerant shortage, capacity is controlled in the inverter in order to maintain low pressure, which results in a decrease in frequency.

(3) Because of (1) and (2) above, the compressor frequency decreases despite a large difference (large load) between temperature set by the remote controller and suction air temperature, resulting that cooling capacity becomes unavailable.

(4) If refrigerant shortage worsens, the electronic expansion valve remains fully open and suction superheated degree further increases. In addition, as compressor frequency drops to the level of the lowest frequency (41 Hz), low pressure cannot be maintained

<Diagnosis of inadequate refrigerant>