Special Control
SiUS371901E
127
Functions and Control
7.3
Defrost Control
To defrost the outdoor heat exchanger while in Evaporator, the defrost control is conducted to recover the heating capacity.
Tb: Heat exchanger deicer temperature
Part name
Electric symbol
Defrost control
Compressor
M1C
REYQ72-120XA: 134 rps
REYQ144/168XA: 119 rps
Inverter fan
M1F, M2F
With high pressure
OFF
←→
Step X/2
←→
Step X
Electronic expansion valve (Heat
exchanger upper)
Y1E
100%
Electronic expansion valve (Heat
exchanger lower)
Y3E
Electronic expansion valve (Subcooling
heat exchanger)
Y2E
0 pulse
Electric expansion valve (Subcooling
injection)
Y4E
760 pulse
Electronic expansion valve (Refrigerant
cooling)
Y5E
Same as normal control
Electronic expansion valve (Receiver
gas purge)
Y7E
0 pulse
Solenoid valve (Oil separator oil return)
Y1S
ON
Solenoid valve (Hot gas bypass)
Y2S
OFF
Solenoid valve (Liquid pipe)
Y3S
ON
Four way valve (HP/LP gas pipe)
Y4S
Hold
Four way valve (Heat exchanger lower)
Y5S
Hold
Four way valve (Heat exchanger upper)
Y6S
Hold
Solenoid valve (Accumulator oil return)
Y7S
ON
Ending condition
•
A lapse of 15 minutes
•
Tb>11°C (51.8°F) continues for 30 seconds or more
OR
Indoor unit actuator
Defrost control
Fan
Thermostat ON unit
OFF
Non-operating unit
OFF
Thermostat OFF unit
OFF
Electronic expansion valve
Thermostat ON unit
Defrost EV opening degree
Non-operating unit
Defrost EV opening degree
Thermostat OFF unit
Defrost EV opening degree
Branch Selector unit actuator
Normal cooling
Normal simultaneous cooling/heating
Normal heating
Cooling
Heating
Electronic
expansion
valve (EVSC)
Y1E
Thermostat ON
0 pulse
0 pulse
Subcooling degree
control
0 pulse
Non-operating
0 pulse
0 pulse
0 pulse
0 pulse
Thermostat OFF
0 pulse
0 pulse
0 pulse
0 pulse
Electronic
expansion
valve (EVH)
Y2E
Thermostat ON
6,000 pulse
0 pulse
6,000 pulse
6,000 pulse
Non-operating
6,000 pulse
0 pulse
6,000 pulse
6,000 pulse
Thermostat OFF
6,000 pulse
0 pulse
6,000 pulse
6,000 pulse
Electronic
expansion
valve (EVL)
Y3E
Thermostat ON
6,000 pulse
6,000 pulse
0 pulse
0 pulse
Non-operating
6,000 pulse
6,000 pulse
0 pulse
0 pulse
Thermostat OFF
6,000 pulse
6,000 pulse
0 pulse
0 pulse
Summary of Contents for REYQ-XA
Page 1: ...Service Manual SiUS371901E REYQ72 456XATJU REYQ72 456XAYDU REYQ72 432XAYCU Heat Recovery 60 Hz...
Page 415: ...SiUS371901E Wiring Diagrams Appendix 402 REYQ144 168XATJU 2D119206A...
Page 416: ...Wiring Diagrams SiUS371901E 403 Appendix REYQ72 96 120XAYDU 2D119207B...
Page 417: ...SiUS371901E Wiring Diagrams Appendix 404 REYQ144 168XAYDU 2D119208B...
Page 418: ...Wiring Diagrams SiUS371901E 405 Appendix REYQ72 96 120 144 168XAYCU 2D119209A...
Page 421: ...SiUS371901E Wiring Diagrams Appendix 408 FXZQ05 07 09 12 15 18TAVJU 3D110443A...
Page 423: ...SiUS371901E Wiring Diagrams Appendix 410 FXEQ07 09 12 15 18 24PVJU 3D098557A...
Page 425: ...SiUS371901E Wiring Diagrams Appendix 412 FXSQ05 07 09 12 15 18 24 30 36 48 54TAVJU C 3D110467C...
Page 426: ...Wiring Diagrams SiUS371901E 413 Appendix FXMQ07 09 12 15 18 24 30 36 48 54PBVJU 3D093209B...
Page 428: ...Wiring Diagrams SiUS371901E 415 Appendix FXHQ12 24 36MVJU 3D048116C...
Page 429: ...SiUS371901E Wiring Diagrams Appendix 416 FXAQ07 09 12 18 24PVJU C 3D075354D...
Page 435: ...SiUS371901E Wiring Diagrams Appendix 422 VAM1200GVJU 3D073270D...
Page 437: ...SiUS371901E Wiring Diagrams Appendix 424 1 4 2 Multi Branch Selector Unit BS4Q54TVJ 3D089123B...
Page 438: ...Wiring Diagrams SiUS371901E 425 Appendix BS6 8Q54TVJ 2D089122B...
Page 439: ...SiUS371901E Wiring Diagrams Appendix 426 BS10 12Q54TVJ 2D089121B...
Page 440: ...Revision History Month Year Version Revised contents 04 2019 SiUS371901E First edition...