Fujitsu AOUH18LMAS1, Service Manual

Page: 171 / 215

8-6. Low outdoor temperature protection
→hen the outdoor temperature sensor detects lower than the trigger condition below, the compres-
sor is stopped.
Operation mode Cooling/Dry
Trigger condition -4°F (-20°C)
Release condition 5°F (-15°C)
8-7. High temperature and high pressure release control
The compressor is controlled as follows.
• Cooling mode
Indoor unit heat exchanger
temperature rises Indoor unit heat exchanger
temperature drops
Stable zone
AB
BC
CD
Zone A
Zone B
Zone C
Zone D
AB: 149.0°F (65°C)
BC: 143.6°F (62°C)
CD: 140.0°F (60°C)
Zone Operation
Zone A Compressor is stopped.
Zone B The compressor frequency is decreased. -7 rps/120 sec.
Zone C
The protection is released and the operation is returned to normal mode.
Zone D
• Heating mode
Indoor unit heat exchanger
temperature rises Indoor unit heat exchanger
temperature drops
Stable zone
AB
BC
CD
DE
Zone A
Zone B
Zone C
Zone D
Zone E
AB: 145.4°F (63°C)
BC: 131.0°F (55°C)
CD: 127.4°F (53°C)
DE: 122.0°F (50°C)
Zone Operation
Zone A Compressor is stopped.
Zone B
The compressor frequency is decreased.
-15 rps/120 sec.
Zone C -2 rps/120 sec.
Zone D
The protection is released and the operation is returned to normal mode.
Zone E
8-6. Low outdoor temperature protection
- (04-33) -
8. Various protections
C
O
N
TR
O
L
A
N
D
FU
N
C
TI
O
N
S
C
O
N
TR
O
L
A
N
D
FU
N
C
TI
O
N
S