Daikin FTXP20-71L Service Manual page 66

3 | Components
Problem solved?
Service manual
66
3 With the unit operating, connect the service monitoring tool to the unit.
4 When the expansion valve is closed according to the service monitoring tool,
check the inlet and outlet of the valve with a contact thermometer or use an
expansion valve stethoscope to see if refrigerant flows through the expansion
valve. Check that the valve is NOT bleeding.
Result: There MUST be NO flow through the expansion valve.
5 When the expansion valve is open according to the service monitoring tool,
check the inlet and outlet of the valve with a contact thermometer or use an
expansion valve stethoscope to see if refrigerant flows through the expansion
valve.
Result: Refrigerant MUST flow through the expansion valve.
6 Wait for the PCB to command the expansion valve to open (when closed) or to
close (when open) (pulse output to expansion valve visible on service
monitoring tool).
INFORMATION
If the PCB does NOT command the expansion valve to open or close (when it is
supposed to), perform a check of the appropriate thermistors and pressure sensors
(as their measurements control the operation of the expansion valve(s)).
7 While in opening or closing sequence each expansion valve winding (Ф1, 2, 3,
4) is supplied with 12 V DC from the PCB. You will need a good multimeter,
where its range is set to about 20 V DC, and during opening or closing
sequence you may be able to measure the supply voltage for a short time. If
you set the multimeter range to Auto, then most likely you may NOT read a
value between switching ranges. The best way to check is to feel the
movement of the valve by touching, rather than trying to measure the driving
voltage.
8 When the expansion valve was commanded to close, check the inlet and
outlet of the valve with a contact thermometer or use an expansion valve
stethoscope to see if refrigerant flows through the expansion valve. Check
that the valve is NOT bleeding.
Result: There MUST be NO flow through the expansion valve.
9 When the expansion valve was commanded to open, check the inlet and
outlet of the valve with a contact thermometer or use an expansion valve
stethoscope to see if refrigerant flows through the expansion valve.
Result: Refrigerant MUST flow through the expansion valve.
Is the flow through the expansion valve
correct?
Yes
No
After all checking procedures listed above have been performed:
Is the problem solved?
Yes
Action
Component is OK. Return to the
troubleshooting of the specific error
and continue with the next step.
Replace the expansion valve, see
"3.3.2 Repair procedures" [
Action
No further actions required.
ATXP20~35 + FTXP20~71 + ARXP20~35 + RXP20~71
4
67].
Split Comfora R32
ESIE18-01E – 2023.01