Daikin Outdoor Unit For Reverse Cycle System RY125LUY1

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 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.

Resistance measurement for phase 1

Resistance measurement for phase 2

Resistance measurement for phase 3

Is the resistance value equal to 5 times or more than the other resistance values?

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.;

Set operation OFF and power OFF. Disconnect the connector.

Keep operation OFF and power OFF. Connect the connector.

2 pulses (0 and 5 VDC) are output 4 times at the pins 1 - 4 when the fan motor is rotated 1 turn by hand.

Sign off on the fan motor pulse check

Warning: This check requires trained personnel with PPE!

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 check

Sign off on the high pressure check

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

Check if there is continuity between the said terminal blocks

If there is no continuity, conduct continuity checks between the transmission wiring terminal blocks F1 and F2 of the unified ON/OFF controller

Conduct continuity checks between the outdoor-outdoor unit terminal of the 'Outdoor Unit E', 'Outdoor Unit D', 'Outdoor Unit C'

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

Turn OFF the power supply to all equipment