Check; High Pressure Check - Daikin SkyAir RZR-TA Series Service Manual

SiUS281811E

5. Check

5.1

High Pressure Check

CHECK 1

Referring to the Fault Tree Analysis (FTA) shown below, probe the defective points.
Rise in high
pressure
[In heating]
If the indoor unit electronic
expansion valve excessively
throttled:
(*2.)
1: In cooling, it is normal if the outdoor unit electronic expansion valve is fully open.
2: In heating, the indoor unit electronic expansion valve is used for subcooling degree control.
Part 6 Service Diagnosis
Local
High pipe
pressure
resistance
rise
[In cooling]
If the outdoor unit electronic
Defective outdoor
expansion valve is throttled: unit electronic
expansion valve
(*1.)
A temperature difference in
excess of 10°C (18°F) between
the inlet and the outlet is
deemed to be abnormal.
Defective
Defective
control
high pressure
control
Defective indoor
unit electronic
expansion valve
Defective
control
[In cooling]
High suction air
temperature of
High suction
outdoor unit
air
temperature
of the High suction
air temperature
condenser
of indoor unit
Defective suction air thermistor of indoor unit
[In heating]
High suction air temperature of outdoor unit
Defective outdoor air temperature thermistor of outdoor unit
Degradation
Dirty condenser
in condensing
capacity
Mixing of non-condensable gas
Decreased
airflow rate
Excessive refrigerant charging
Improper model selection [In heating]
←Check to be sure the stop valve is open.
Stop valve closed
Bent or crushed pipe
←Conduct visual checks for pipe conditions.
←Is there any temperature difference caused before
Clogging of foreign
and after the filter or branch pipe?
materials
Defective valve coil ←Are the coil resistance and insulation normal?
Defective valve body
←Is the pressure value checked with the Service Checker
Defective high pressure sensor
corresponding to the measurement value of the pressure sensor?
Defective main
←Are the voltage characteristics normal?
PCB
←Are the coil resistance and insulation
Defective valve coil
normal?
Defective valve body
Defective high pressure sensor
←Is the pressure value checked with the Service
Checker corresponding to the measurement value of
the pressure sensor?
Defective indoor unit
←Is the connector properly connected?
liquid pipe thermistor
Are the thermistor resistance characteristics normal?
Defective main ←Are the voltage characteristics normal?
PCB
←Is the suction air temperature more than 43°C
Short circuit
(109°F)?
←Is the outdoor air temperature more than 43°C
High outdoor air
temperature
(109°F)?
←Is the suction air temperature more than 27°C
Short circuit
(80.6°F)?
High room
←Is the room temperature more than 27°C (80.6°F)?
temperature
←Is the connector properly connected?
Are the thermistor resistance characteristics normal?
←Is the outdoor air temperature more than 16°CWB
(60.8°FWB)?
←Is the connector properly connected?
Are the thermistor resistance characteristics normal?
←Is the heat exchanger clogged? (In cooling)
←Is air or else mixed in the refrigerant system?
Defective fan
←Can the fan motor be rotated with hands?
Decreased
motor
fan
output
Defective main
PCB (Including
←If a spare PCB is installed, is the capacity
capacity setting)
High Dirty filter ←Is the air filter clogged?
airflow
passage
resistance
←Is there any obstacle in the airflow passage?
Obstacle
←Refer to CHECK 6 .
←Is the indoor unit too small compared to
the large-sized outdoor unit?
Are the motor coil resistance and
insulation normal?
setting properly made?
Check
261