Outline of Control (Indoor Unit)
SiAF332111E
88
Part 4 Functions and Control
3.10 Electronic Expansion Valve Control
Electronic expansion valves in indoor units have the functions of conducting superheating
degree control in cooling operation. However, if the indoor units receive any control command
such as a protection control command or a special control command from the outdoor unit, the
units will give a priority to the control command.
• Superheating degree control in cooling operation
This function is used to adjust the opening of the electronic expansion valve so that
superheating degree (SH), which is calculated from the detection temperature (Tg) of the gas
pipe thermistor (R3T) and the detection temperature (Tl) of the liquid temperature thermistor
(R2T) of the indoor unit, will come close to a target superheating degree (SHS).
At that time, correction to the superheating degree is made according to the differences (ΔT)
between set temperature and suction air temperature.
SH = Tg – Tl
where,
SH: Evaporator outlet superheating degree (°C)
Tg: Indoor unit gas pipe temperature (R3T)
Tl: Indoor unit liquid pipe temperature (R2T)
SHS (Target superheating degree)
• Normally 5°C.
• As ΔT (Remote controller set temp. – Suction air temp.) becomes larger, SHS becomes lower.
• As ΔT (Remote controller set temp. – Suction air temp.) becomes lower, SHS becomes larger.
3.11 Circulation Airflow (FXFSQ-AR only)
Unevenness of room temperature and the startup time are improved by repeating 2-direction
horizontal blow-off and swing alternately.
3.11.1 Initiation Conditions of Circulation Operation
When operation starts (in the startup state)
Circulation airflow operation is performed.
During normal operation
The unit automatically determines operation based on the room temperature condition and time
to switch circulation airflow operation and the normal auto airflow rate and direction (eco full
automatic control).
Circulation airflow operation continues for up to 90 minutes
Set temp.
Target temp.
Δ
t
Circulation airflow
Auto airflow rate and direction
Circulation airflow
Time
Room temp.
Summary of Contents for VRV S RXMQ10ARY1
Page 1: ...Service Manual Cooling Only 50 60 Hz RXQ4 5ARV1 RXMQ6ARV1 RXMQ8 10 12ARY1 SiAF332111E...
Page 369: ...SiAF332111E Wiring Diagrams Part 7 Appendix 363 RXMQ6ARV1 C 3D137051...
Page 370: ...Wiring Diagrams SiAF332111E 364 Part 7 Appendix RXMQ8ARY1 C 3D137060...
Page 371: ...SiAF332111E Wiring Diagrams Part 7 Appendix 365 RXMQ10 12ARY1 3D121610B...
Page 375: ...SiAF332111E Wiring Diagrams Part 7 Appendix 369 FXMQ40 50 63 80 100ARV1 3D127112 04 59...