Midea MV6-i400WV2GN1-E - Defrosting Operation; Indoor Unit Component Control During Defrosting Operation; Outdoor Unit Component Control During Defrosting Operation

V6-i VRF 50/60Hz
47
Part 3
- Control
7.2 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 unit running time. When the outdoor unit is
running in defrosting, the digital display on outdoor main PCB will display “df”.
Table 3-7.5: Outdoor unit component control during defrosting operation
Component
Wiring
diagram label
8-12HP
14-18HP
20-24HP
26-28HP
30-32HP
Control functions and states
Inverter compressor A
COMP(A)
●
●
●
●
●
Fixed frequency
Inverter compressor B
COMP(B)
●
●
●
DC fan motor A
FANA
●
●
●
●
●
Off
DC fan motor B
FANB
●
●
●
Electronic expansion valve A
EXVA
●
●
●
●
●
Position 480 (steps) or 3000
(steps)
Electronic expansion valve C
EXVC
●
●
●
●
●
Position 480 (steps)
Four-way valve
ST1
●
●
●
●
●
Off
Solenoid valve (oil balance)
SV4
●
●
●
●
●
Normal control
Solenoid valve (fast defrosting)
SV5
●
●
●
●
●
On
Solenoid valve (EXV bypass)
SV6
●
●
●
●
●
On
Solenoid valve (indoor units
bypass)
SV7
●
●
Normal control
Solenoid valve (inverter
compressor A vapor injection)
SV8A
●
●
●
●
Off
Solenoid valve (inverter
compressor B vapor injection)
SV8B
●
●
Off
Solenoid valve (inverter
compressor B pressure balance)
SV9
●
●
●
Open before compressor B
startup
Table 3-7.6: Indoor unit component control during defrosting operation
Component
Unit state
Control functions and states
Fan
Thermo on
Off
Standby
Off
Thermo off
Off
Electronic expansion valve
Thermo on
480 (steps)
Standby
480 (steps)
Thermo off
480 (steps)