V4+R VRF 50/60Hz
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Midea V4+R Series Service Manual
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
Control functions and states
Controlled according to load requirement
Electronic expansion valve A
Electronic expansion valve B
Solenoid valve (liquid refrigerant injection)
Solenoid valve (oil balance)
Solenoid valve (fast defrosting)
Table 3-7.6: Indoor unit component control during defrosting operation
Control functions and states
Electronic expansion valve