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Daikin VRV III-S RXYMQ36 48PVJU Service Manual: Troubleshooting

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CHECK 1
Check for Causes of Rise in High Pressure
Referring to the Fault Tree Analysis (FTA) shown below, probe the faulty points.
Local
pressure
rise
[In cooling]
If the outdoor unit electronic
expansion valve is throttled:
(See *1.)
Rise in high
pressure
Faulty high
pressure
control
[In heating]
If the indoor unit electronic
expansion valve excessively
throttled:
(See *2.)
High suction
air
temperature
of the
condenser
Degradation
in condensing
capacity
Excessive refrigerant charging
Improper model selection [In heating]
*1: In cooling, it is normal if the outdoor unit electronic expansion valve (EV1) is fully open.
*2: In heating, the indoor unit electronic expansion valve is used for "subcooled degree control".
(For details, refer to "Electronic Expansion Valve Control".)
210
High pipe
resistance
Faulty outdoor
unit electronic
expansion valve
A temperature di f ference i n excess of 50°F
between the i n l e t and the outl e t i s deemed to be abnormal .
Faulty
control
Faulty indoor
unit electronic
expansion valve
Faulty
control
[In cooling]
High suction air
temperature
of outdoor unit
High suction
air temperature
of indoor unit
Faulty suction air thermistor of indoor unit
[In heating]
High suction air temperature of outdoor unit
Faulty outdoor temperature thermistor of outdoor unit
Dirty condenser
Mixing of non-condensable gas
Decreased
fan airflow
rate
←Check to be sure the stop valve is open.
Stop valve closed
←Conduct visual checks for pipe conditions.
Bent or crashed pipe
←Is there any temperature difference caused before
Clogging of foreign
particles
←Are the coil resistance and insulation normal?
Faulty valve coil
Faulty valve body
←Are the electrical characteristics normal?
Faulty high pressure sensor
←Is the pressure value checked with the Service Checker
Faulty control PCB
←Are the coil resistance and insulation
Faulty valve coil
Faulty valve body
←Are the electrical characteristics normal?
Faulty high pressure sensor
←In the connector properly connected?
Faulty indoor unit
liquid pipe thermistor
←Is the pressure value checked with the Service
Faulty control PCB
Short circuit
High ambient temperature
Short circuit
High ambient temperature
←Is the heat exchanger clogged? (In cooling)
←Is air or else mixed in the refrigerant system?
Faulty fan
Decreased
motor
fan
Faulty control
output
PCB
(Including
capacity setting)
Dirty filter
High air
passage
resistance
Obstacle
←Refer to troubleshooting "
←Is the indoor unit too small compared to
the large-sized outdoor unit?
and after the filter or branch pipe.
corresponding to the measurement of the pressure sensor?
normal?
Are the thermistor resistance characteristics normal?
Checker corresponding to the measurement of the
pressure sensor?
←Is the suction air temperature not more than
109.4°F?
←Is the outdoor temperature not more than 109.4°F?
←Is the suction air temperature not more than 80.6°F?
←Is the indoor temperature not more than 80.6°F?
←Is the connector properly connected?
Are the thermistor resistance characteristics normal?
←Is the outdoor temperature not more than 60.8°FWB?
←Is the connector properly connected?
Are the thermistor resistance characteristics normal?
←Can the fan motor be rotated with hands?
Are the motor coil resistance and
insulation normal?
←If a spare PCB is mounted, is the capacity
setting properly made?
←Is the air filter clogged?
←Is there any obstacle in the air passage?
F6
".
SiUS34-907

Troubleshooting

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R-410a

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  • cp shukla Feb 16, 2016 06:50:
    RXYQ18PAY6 service manual & vrv Fulform