Key Components; Part 3 Control - Midea V6-i Series Service Manual

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Key components:

1. Oil separator:
Separates oil from gas refrigerant pumped out of the compressor and quickly returns it to the compressor. Separation
efficiency is up to 99%.
2. Accumulator:
Stores liquid refrigerant and oil to protect compressor from liquid hammering.
3. Electronic expansion valve (EXV):
Controls refrigerant flow and reduces refrigerant pressure.
4. Four-way valve:
Controls refrigerant flow direction. Closed in cooling mode and open in heating mode. When closed, the heat
exchanger functions as a condenser; when open, the heat exchanger functions as an evaporator.
5. Solenoid valve SV4:
Returns oil to the compressor. Opens once the compressor has run for 200 seconds and closes 600 seconds later and
then opens for 3 minutes every 20 minutes.
6. Solenoid valve SV5:
Enables fast defrosting in heating mode and unloading in cooling mode. During defrosting operation, opens to
shorten the refrigerant flow cycle and quicken the defrosting process. In cooling mode, SV5 opens when outdoor
ambient temperature is above 40
7. Solenoid valve SV6:
Allows refrigerant to bypass the expansion valves. Opens in cooling mode when discharge temperature exceeds the
limit. Closed in heating mode and standby.
8. Solenoid valve SV7:
Allows refrigerant to return directly to the compressor. Opens when indoor air temperature is close to the set
temperature to avoid frequent compressor on/off.
9. Solenoid valve SV8A / SV8B:
Allows refrigerant from plate heat exchanger inject directly to the compressor. SV8A opens when compressor A
startup and closes when compressor A stop. SV8B delays opening when compressor B startup and closes when
compressor B stop.
10. Solenoid valve SV9:
Balances compressor B pressure. Opens before compressor B startup and closed after compressor B running for 15
seconds. Opens after compressor B stops 10s and keep opening 60s.
11. High and low pressure switches:
Regulate system pressure. When system pressure rises above the upper limit or falls below the lower limit, the high or
low pressure switches turn off, stopping the compressor. After 10 minutes, the compressor restarts.
o
C or compressor frequency is below 41Hz.
V6-i VRF 50/60Hz
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