Daikin VRV Aurora Series Air Conditioner RXLQ120TBTJA

Check the fan motor connector according to the following procedure.

2. Measure the resistance between phases of U, V, W at the motor side connectors (3-core wire) to check that the values are balanced and there is no short circuiting, while connector or relay connector is disconnected.;

CHECKING EMERSON ULTRATECHTM ECM MOTORS

The FXTQ-TA and FXTQ-TB models utilize an Emerson, 4-wire variable speed ECM blower motor.

The ECM blower motor provides constant CFM.

The motor is a serially communicating variable speed motor. Only four wires are required to control the motor: +Vdc, Common, Receive, and Transmit.

The +Vdc and Common wires provide power to the motor's low voltage control circuits.

General Checks / Considerations

1. Check power supply to the air handler or modular blower. Ensure power supply is within the range specified on rating plate.

2. Check motor power harness. Ensure wires are continuous and make good contact when seated in the connectors. Repair or replace as needed.

3. Check motor control harness. Ensure wires are continuous and make good contact when seated in the connectors. Repair or replace as needed.

Warning: This check requires trained personnel with PPE!

Enter the superheating degree of suction gas

Is the compressor discharge gas temperature higher?

Does the electronic expansion valve turn open?

Does the unit not demonstrate cooling/heating capacity?

Sign off on the refrigerant shortage 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 central remote controller using a multimeter

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

If there is no continuity as well, conduct continuity checks between the outdoor-outdoor unit terminal of the outdoor unit E, between the outdoor-outdoor unit terminal of the outdoor unit D, between the outdoor-outdoor unit terminal of the outdoor unit C

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

Warning: Ensure power is OFF before starting the procedure

Remove all the wiring connected to the PCB where power transistors are mounted on

Prepare the analog type of multimeter. For the digital type of multimeter, those with diode check function are available for the checking.

For RXLQ96/120TATJU, RXLQ96/120TATJA, RXLQ96/120TBTJA models

Turn OFF the power supply. Then, after a lapse of 10 minutes or more, make measurement of resistance.

Enter the resistance measurement

Sign off on the power transistor check