Tables 3-7.3 and 3-7.4 show component control during oil return operation in heating mode.
Table 3-7.3: Outdoor unit component control during oil return operation in heating mode
Component
Inverter compressor A
Inverter compressor B
DC fan motor A
DC fan motor B
Electronic expansion valve A
Electronic expansion valve C
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)
Solenoid
valve
(inverter
compressor A vapor injection)
Solenoid
valve
(inverter
compressor B vapor injection)
Solenoid
valve
(inverter
compressor B pressure balance)
Wiring
8-12HP
diagram label
COMP(A)
COMP(B)
FANA
FANB
EXVA
EXVC
ST1
SV2
SV4
SV5
SV6
SV7
SV8A
SV8B
SV9
Table 3-7.4: Indoor unit component control during oil return operation in heating mode
Component
Fan
Electronic expansion valve
14-18HP
20-24HP
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
Unit state
Control functions and states
Thermo on
Off
Standby
Off
Thermo off
Off
Thermo on
480 (steps)
Standby
480 (steps)
Thermo off
480 (steps)
51
26-28HP
30-32HP
Control functions and states
●
●
Fixed frequency
●
●
Fan speed controlled according
●
●
to discharge pressure
●
●
Position 480 (steps) or 3000
●
●
(steps)
Position 96 (steps)
●
●
Off
●
●
Normal control
Normal control
●
●
On
●
●
On
●
●
Normal control
●
Off
●
●
Off
●
●
Open
●
●
startup
before compressor
B