Daikin RXQ12AHR, Руководство по обслуживанию

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Outline of Control (Indoor Unit) SiAF341904E
102 Part 4 Functions and Control
8.10 Electronic Expansion Valve Control
Electronic expansion valves in indoor units have the functions of conducting superheated
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.
• Superheated degree control in cooling operation
This function is used to adjust the opening of the electronic expansion valve so that
superheated 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 superheated degree (SHS).
At that time, correction to the superheated degree is made according to the differences (ΔT)
between set temperature and suction air temperature.
SH = Tg – Tl
SH: Evaporator outlet superheated degree (°C)
Tg: Indoor unit gas pipe temperature (R3T)
Tl: Indoor unit liquid pipe temperature (R2T)
SHS (Target superheated 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.