Repair Procedures - Daikin VRV IV+ Service Manual

3 Components
To perform an electrical check of the expansion
valve
Prerequisite: First perform a mechanical check of the expansion
valve, see "3.5.1 Checking procedures" on
1 Make sure that the valve coil is firmly slid onto the valve body.
2 Disconnect the electrical connector of the expansion valve
motor from the appropriate PCB and measure the resistance of
all windings (between the pins of each phase (wire) and the
common wire) using a multi meter. All measurements MUST be
approximately the same.
Name Symbol Location
(PCB)
Main Y1E Main
expansion
valve
Sub‑cool Y2E Main
expansion
valve
Liquid Y3E Main
cooling
expansion
valve
Storage Y4E Indoor
vessel
expansion
valve
INFORMATION
Below is an example of the resistance measurements in
which the common wire is connected to pin 6 of the
expansion valve motor connector. Connections may differ
according to the type of expansion valve.
▪ Connector pin 1‑6,
▪ Connector pin 2‑6,
▪ Connector pin 3‑6,
▪ Connector pin 4‑6.
a
a Connector
Is the measured resistance
correct?
Yes
No
To perform an operation check of the expansion
valve
Prerequisite: First perform an electrical check of the expansion
valve, see "3.5.1 Checking procedures" on
Service manual
90
https://daikin-p.ru/catalog/vrv-daikn/naruzhnye-vrv-bloki-daikin
page 89.
Connector Measured
winding
resistances
X21A 150±15 Ω
X22A 46±3 Ω
X23A 46±3 Ω
X25A 150±15 Ω
Action
Perform an operation check of
the expansion valve, see
"3.5.1 Checking procedures" on
page 89.
Replace the expansion valve
motor, "3.5.2 Repair
procedures" on page 90.
page 89.
1 Turn ON the power of the unit.
INFORMATION
When power is switched ON, PCB checks all expansion
valve coil windings by current check. If winding is short or
open, expansion valve error is triggered.
2 Start the unit operation (via the user interface, operation switch,
central controller, ...).
3 With the unit operating, connect the service monitoring tool to
the unit.
4 When the expansion valve is closed, check the valve inlet and
outlet for any leaks. Replace the valve body if any leaks are
found, see "3.5.2 Repair procedures" on
5 Wait for the PCB to command the expansion valve to open
(pulse output to expansion valve visible on service monitoring
tool).
INFORMATION
If the PCB does NOT command the expansion valve to
open (when it is supposed to), perform a check of the
appropriate thermistors and pressure sensors (expansion
valves are driven by superheat or subcool value calculated
through the thermistors).
6 While in opening or closing sequence each expansion valve
winding (Ф1, 2, 3, 4) is supplied with 12 V DC from the PCB in
the sequence given above. 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.
7 Check if the expansion valve is open. Check with a contact
thermometer (or by touching) if refrigerant flows through the
expansion valve.
Is the expansion valve open?
Yes
No
Problem solved?
After all checking procedures listed above have been performed:
Is the problem solved?
Yes
No
3.5.2

Repair procedures

To remove the expansion valve motor
Prerequisite: Stop the unit operation (via the user interface, central
controller, operation switch, ...).
Prerequisite: Turn OFF the respective circuit breaker.
Prerequisite: Remove the required plate work, see
work" on page 118.
1 If needed, remove any parts or insulation to create more space
for the removal.
2 Cut the tie strap and remove the insulation cap.
page 90.
Action
Component is OK. Return to the
troubleshooting of the specific
error and continue with the next
step.
Replace the expansion valve,
see "3.5.2 Repair procedures" on
page 90.
Action
No further actions required.
Return to the troubleshooting of
the specific error and continue
with the next procedure.
"3.13 Plate
RYYQ+RYMQ+RXYQ8~20U7Y1B
VRV IV+ Heat Pump
ESIE18-14 – 2019.07