Outline of Control (Indoor Unit)
SiUS371901EB
173
Part 4 Functions and Control
9.7 Freeze-Up Prevention Control
When the temperature detected by the liquid pipe temperature thermistor of the indoor heat
exchanger drops too low, the unit enters freeze-up prevention control in accordance with the
following conditions, and is also set in accordance with the conditions given below. (Thermostat
OFF)
When freeze-up prevention is activated, the electronic expansion valve is closed, the drain pump
turns on and the airflow rate is fixed to L tap. When the following conditions for cancelling are
satisfied, it will reset.
Conditions for starting:
Liquid pipe temperature
≤
– 1°C (30.2°F) (for total of 40 minutes)
or
Liquid pipe temperature
≤
– 5°C (23°F) (for total of 10 minutes)
Condition for cancelling:
Liquid pipe temperature
≥
+7°C (44.6°F) (for 10 minutes continuously)
Concept of freeze-up prevention control
System avoids freeze-up
· For comfort, system avoids unnecessary thermostat ON/OFF
· For ensuring compressor reliability, system avoids unnecessary compressor ON/OFF
When freeze-up prevention control starts, system makes sure the frost is completely removed.
· System avoids water leakage.
Freeze-Up Prevention by Off Cycle (Indoor Unit)
N
ormal operation
Start
Cancel
Li
qu
id pipe
temperat
u
re
Start
Cancel
N
ormal operation
–
5
ºC
(23˚F)
0
ºC
(32˚F)
+
7
ºC
(44.6˚F)
–
1
ºC
(30.2˚F)
t1
t2
t3
t4
0
ºC
(32˚F)
+
7
ºC
(44.6˚F)
10 min.
OR
10 min.
10 min.
t
>
40
min
u
tes
Freeze-
u
p pre
v
ention control
Forced OFF
b
y thermostat
Freeze-
u
p pre
v
ention control
Forced OFF
b
y thermostat
Summary of Contents for REYQ72-432XAYCU
Page 455: ...SiUS371901EB Wiring Diagrams Part 7 Appendix 448 REYQ144 168XATJU REYQ144 168XATJA 2D119206B ...
Page 457: ...SiUS371901EB Wiring Diagrams Part 7 Appendix 450 REYQ144 168XAYDU REYQ144 168XAYDA 2D119208C ...
Page 461: ...SiUS371901EB Wiring Diagrams Part 7 Appendix 454 FXZQ05 07 09 12 15 18TAVJU 3D110443A ...
Page 463: ...SiUS371901EB Wiring Diagrams Part 7 Appendix 456 FXEQ07 09 12 15 18 24PVJU 3D098557A ...
Page 464: ...Wiring Diagrams SiUS371901EB 457 Part 7 Appendix FXDQ07 09 12 18 24MVJU C 3D050501C ...
Page 468: ...Wiring Diagrams SiUS371901EB 461 Part 7 Appendix FXHQ12 24 36MVJU 3D048116C ...
Page 469: ...SiUS371901EB Wiring Diagrams Part 7 Appendix 462 FXAQ07 09 12 18 24PVJU 3D075354F ...
Page 475: ...SiUS371901EB Wiring Diagrams Part 7 Appendix 468 VAM1200GVJU 3D073270D ...
Page 478: ...Wiring Diagrams SiUS371901EB 471 Part 7 Appendix BS6 8Q54TVJ 2D089122B ...
Page 479: ...SiUS371901EB Wiring Diagrams Part 7 Appendix 472 BS10 12Q54TVJ 2D089121B ...
Page 481: ...SiUS371901EB Wiring Diagrams Part 7 Appendix 474 BSF6 8Q54TVJ 2D123905A ...