69
4-6. Refrigerant Recovery from Failed Outdoor Unit
(Pump-Down Operation under Follower Outdoor Unit
Backup Scenario)
TL
PMV1
TD2
TS1
SV2
TE1
SV3D
PMV2
TK2
SV3B
TK1
SV3A
HPS
HPS
HPS
TD1
TK
SV3E
TK5
SV41
SV42
PMV4
TE2
TD3
SV43
TK3
SV6
TO
SV3F
SV3
SV
SV
SV
SV
SV
SV
S
V
S
V
SV
SV
S
V
TL
PMV1
TD2
TS1
SV2
SV5
TE1
SV3D
PMV2
TK2
SV3B
TK1
SV3A
HPS
HPS
TD1
TK4
SV3E
TK5
SV41
SV42
A3
SV3C
TO
SV
SV
SV
SV
SV
SV
S
V
S
V
S
V
TC2
TCJ
TC1
TC2
TCJ
TC1
TC2
TCJ
TC1
TC2
TCJ
TC1
PMV
PMV
PMV
PMV
Header unit (MMY-MAP1604*)
Follower unit (MMY-MAP1204*)
Failure
FM
4-Way valve
Pressure sensor
(high pressure)
O.S.
Pressure sensor
(low pressure)
Accumulator
Liquid tank
Compressor
1
Compressor
2
Compressor
3
Balance pipe
Liquid pipe
Gas pipe
Liquid pipe
Gas pipe
Indoor unit
FM
4-Way valve
Liquid line bypass
Pressure sensor
(high pressure)
Pressure sensor
(low pressure)
O.S.
Accumulator
Compressor
1
Compressor
2
Liquid
tank
Balance pipe packed valve
= Full opening
Gas-side service valve = Full opening
⇒
Full closure 10 minutes after system startup
Liquid-side service valve
= Full closure
Refrigerant recovery line
High-pressure gas or condensate liquid refrigerant
Evaporative gas refrigerant (low-pressure gas)
Normal refrigerant line
Note: The "header unit" is the outdoor unit to which the indoor-outdoor communication
line is connected. All other outdoor units are called "follower units".
(The diagram shows a 28 HP system
(16 HP + 12 HP) as an example.)