Table of Contents
SiUS181305E
7.33 Check for Outdoor Unit
7.33.1 Check for Causes of Rise in High Pressure
Check No.30
Referring to the Fault Tree Analysis (FTA) shown below, probe the faulty points.
Local
pressure
rise
Rise in high
pressure
If the outdoor unit
electronic
expansion valve is
throttled: (See ∗1.)
Faulty
high
pressure
control
High suction
air
temperature
of the
condenser
In heating
Degradation
in condensing
capacity
Excessive refrigerant charging
Improper model selection
∗1: In cooling, it is normal if the outdoor unit electronic expansion valve (Y1E) is fully open.
Troubleshooting
High pipe
resistance
Faulty outdoor
unit electronic
expansion valve
A temperature
difference in excess of
10°C (18°F) between
the inlet and the outlet
is deemed to be
abnormal.
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
High suction air temperature of outdoor unit
Faulty outdoor temperature thermistor of outdoor unit
Dirty condenser
Mixing of non-condensable gas
Decreased
fan
Decreased
output
fan airflow
rate
High air
passage
resistance
In heating
Troubleshooting for Outdoor Unit
←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
Clogging of foreign
before and after the filter or branch pipe?
particles
←Are the coil resistance and insulation normal?
Faulty valve coil
Faulty valve body
Faulty high pressure
←Are the electrical characteristics normal?
sensor
←Is the pressure value checked with the
Faulty control PCB
Service Checker corresponding to the
measurement of the pressure sensor?
←Is the suction air temperature not more than
Short-circuit
46°C (114.8°F)?
←Is the outdoor temperature not more than
High ambient
temperature
46°C (114.8°F)?
←Is the suction air temperature not more than
Short-circuit
27°C (80.6°F)?
←Is the indoor temperature not more than
High ambient
temperature
27°C (80.6°F)?
←Is the connector properly connected?
Are the thermistor resistance characteristics normal?
←Is the outdoor temperature not 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?
Faulty fan
←Can the fan motor be rotated with hands?
motor
Are the motor coil resistance and
insulation normal?
Faulty control
PCB
←If a spare PCB is mounted, is the capacity
(Including
setting properly made?
capacity setting)
←Is the air filter clogged?
Dirty filter
←Is there any obstacle in the air passage?
Obstacle
←Refer to troubleshooting
←Is the indoor unit too small compared to
the large-sized outdoor unit?
F6
.
(R19097)
220
- Quick Links:
- Outdoor Unit
- Rmxs48Lvju
- Ffq09/12/15/18Lvju
Hide quick links:
Chapters
Table of Contents
Troubleshooting
