Midea MV5-X252W/V2GN1 Service Manual page 35

V5 X VRF 50/60Hz
7.3 Defrosting Operation
In order to recover heating capacity, the defrosting operation is conducted when the outdoor unit heat exchanger is
performing as an evaporator. The defrosting operation is controlled according to outdoor ambient temperature, outdoor
heat exchanger temperature, indoor heat exchanger temperature and outdoor units running time.
Table 3-7.5: Outdoor unit component control during defrosting operation
Component
Inverter compressor A
Inverter compressor B
DC fan motor A
DC fan motor B
Electronic expansion valve A
Electronic expansion valve B
Four way valve
Solenoid valve (liquid refrigerant injection)
Solenoid valve (oil balance)
Solenoid valve (fast defrosting)
Solenoid valve (EXV bypass)
Solenoid valve (indoor units bypass)
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Wiring diagram label
COMP(INV)
COMP(INV1)
FANA
FANB
EXVA
EXVB
ST1
SV2
SV4
SV5
SV6
SV7
Table 3-7.6: Indoor unit component control during defrosting operation
Component
Thermo on
Fan
Thermo off
Thermo on
Electronic expansion valve
Thermo off
8-12HP 14-22HP
● ●
●
● ●
●
● ●
●
● ●
● ●
● ●
● ●
● ●
● ●
Unit state Control functions and states
Off
Standby Off
Off
480 (steps)
Standby 480 (steps)
480 (steps)
Control functions and states
Controlled according to load requirement
Off
Fully open
Off
Normal control
Normal control
On
On
Normal control
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