Gree Ultra Heat GMV-V72W/A-F, Service Manual, Page: 134 / 240

Ultra Heat GMV VRF Technical Service Manual MAINTENANCE
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Labels on the 4-way valve and their meanings: D
– connects to exhaust; E – connects to IDU
evaporator; S
– connects to intake of gas separator; C – connects to condenser. When the system is
cooling, the pipe at side C works at high pressure high temperature, the pipes at sides E and S work at
low pressure low temperature; when the system is heating, the pipe at side E works at high pressure
high temperature, the pipes at sides C and S work at low pressure low temperature. The pipe at side D
connects to exhaust and it is always working at high pressure high temperature. When units are starting,
defrosting, or returning oil, the valve will vibrate obviously. DO NOT touch the pipe; or, you may be
scalded.
(3) Oil solenoid valve: This valve can be operated based on its state that is shown through the
monitoring software and actual situation. When this valve is opened, the coil will be heated and
lubricant at both sides of the valve flows.
Step 4: Test the IPM module of compressor drive board and PFC board to see whether it is
normal.
1) Disconnect the power supply. Five minutes later, remove the line of the faulty compressor.
2) Set a multimeter to gear diode.
For Drive board:
Use the black probe of the multi-meter to touch the place marked by P and the red probe to touch
places marked by U, V and W respectively and record readings of the multi-meter. Use the red probe to
touch the place marked by N and black probe to touch places marked by U, V and W respectively and
record readings of the multi-meter.
For PFC board:
Use the black probe of the multi-meter to touch the place marked by P and the red probe to touch
places marked by L1, L2 and L3 respectively and record readings of the multi-meter. Use the red probe
to touch the place marked by N and black probe to touch places marked by L1, L2 and L3 respectively
and record readings of the multi-meter.
3) Analyzing: If the reading ranges between 0.3 V and 0.7 V in the above-mentioned six scenarios,
the IPM module is normal. If the reading is 0 in one or multiple scenarios, the IPM module is damaged.
Oil valve