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Components
Service manual
246
REYQ8~20+REMQ5U7Y1B
VRV IV+ Heat Recovery
ESIE18-15B – 2020.05
a
a
Connector
Is the measured resistance correct?
Action
Yes
Perform an operation check of the
expansion valve, see
No
Replace the expansion valve coil,
247].
To perform an operation check of the expansion valve
Prerequisite:
First perform an electrical check of the expansion valve, see
244].
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 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
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. 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.
▪
Opening sequence for Y1E, Y3E Y4E and Y6E:
Valve closing: 1 > 2 > 3 > 4 > 1
Valve opening: 4 > 3 > 2 > 1 > 4
Summary of Contents for VRV IV+
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