Daikin VRVII - Check the Factors of Overheat Operation

Troubleshooting by Indication on the Remote Controller
351
Check the Factors of Overheat
Operation
Referring to the Fault Tree Analysis (FTA) shown below,
probe the defective points.
CHECK 3
Superheat due to shaft
damage
Superheat due to
defective compressor
Defective
discharge
pipe
temperature
control
Compressor
overheat
Hot gas circuit
clogging
Defective hot
gas bypass
control
Defective
solenoid valve
coil
Defective
solenoid valve
body
Defective
service
monitor PCB
Defective four
way valve
operation
Four way
valve is in the
middle
position.
Leak from hot
gas bypass
valve
← Are the coil resistance and
insulation normal?
← Check if the piping
temperature connected to
the four way valve is
normal.
Defective
subcooling
electronic
expansion
valve
control
(EV2)
(∗1)
Defective
subcooling
electronic
expansion
valve
Defective
control
Defective
valve coil
Defective
valve body
Defective
service
monitor
PCB
Defective
low
pressure
sensor
Defective
subcooling
heat
exchanger
outlet
thermistor
← Are the coil
resistance and
insulation normal?
← Are the electric
characteristics
normal?
← Is the connector
properly
connected?
Are the thermistor
resistance
characteristics
normal?
Temperature
increase of
discharge
pipe
[In cooling only]
(∗2)
← Is the pressure
value checked with
the Service Checker
corresponding to
the measurement
value of the
pressure sensor?
A