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Applies to AOUA**RLCV, AOUA**TLCV, AOUA**RLBV, AOUA**RLBV1, AoUA**RLCV outdoor units.
Target low-pressure and high-pressure control
For cooling mode, the VRF capacity of the compressor will be controlled by low-pressure sensor.
For heating mode, the VRF capacity of the compressor will be controlled by high-pressure sensor.
Outdoor Fan Operation:
Cooling:
The fan speed is controlled to keep high pressure saturation temperature within the target range as follows The high-pressure is monitoring at a set time interval and the fan speed is changed by the following conditions.
(Conditions which raise the fan speed) High-pressure saturation upper limit of target high-pressure saturation or heat sink temperature 176°F(80°C)
(Conditions which lower the fan speed) High-pressure saturation low limit of target high-pressure saturation range and heat sink temperature 167°F(75°C).
Heating Operation:
The fan speed during all heating is constant with Fan step 16* regardless of the outdoor air temperature. Which is 880 or 920 RPM
The EEV controls the flow of refrigerant in outdoor unit:
EEV1 in cooling mode 0-480 Pulses
EEV1 In Heating mode, controls to ( SH control (TH7,TH8 - LPS ) "Target SH: 8 F (4 C) " - Protection (TH1) (LPS), 11-480 Pulses
EEV2 in cooling mode 0-480 Pulses
EEV2 In Heating mode, controls to ( SH control (TH7,TH8 - LPS ) "Target SH: 8 F (4 C) " - Protection (TH1) (LPS), 11-480 Pulses
EEV3 In Cooling Mode, controls to ( SH control (TH6 - LPS ) "Target SH: 8 F (4 C) " - Protection (TH1), 0-500 Pulses
EEV3 In Heating Mode, controls to ( SH control (TH6 - LPS ) "Target SH: 8 F (4 C) " - Protection (TH1), 0-500 Pulses
Oil Recovery operation:
Purpose of the operation:
The amount of refrigerant lubricant oil which has been transported to the indoor units and the connection pipe with the refrigerant will become large as the operation time of compressor increases. It is necessary to recover the oil back into the outdoor unit for a certain time interval in order to prevent compressors from damaging due to lack of lubrication oil.
Cooling oil recovery operation:
< Start condition >
Compressor accumulated operation time since last cooling oil recovery operation exceeds 3 hours (first time : 1hour)
< End condition > 30 seconds have elapsed since the start and "suction temperature - low pressure saturation temperature 10 F(5 C) at all outdoor units or 6 minutes have elapsed since the start.
< Operation >
COMPRESSOR: Performed by all INV compressors and the constant speed compressors operating up until now INV speed varies depending on the operation state. EEV Opening (Indoor/Outdoor unit): Controlled pulse (as normal operation mode). FAN speed (Indoor/Outdoor unit) : Controlled fan speed (as normal operation mode).
Heating oil recovery operation:
< Start condition >
Compressor accumulated operation time since the last heating oil recovery exceeds 8 hours (first time : 1hour)
< End condition > After 4 minutes have elapsed
< Operation >
COMPRESSOR: Performed by all INV compressors and the constant speed compressors operating up until now INV speed varies depending on the operation state. EEV Opening (Indoor/Outdoor unit) : Controlled pulse (as normal operation mode) FAN speed (Indoor/Outdoor unit) : Controlled fan speed (as normal operation mode)
Defrost Operation Control:
Accumulated heating operation time is 40 minutes or longer (Accumulated heating operation time is reset at the end of cooling operation or defrosting operation.) And One of Heat-Ex satisfies condition or or below
Condition : 1. Accumulated operating time is 150 minutes* or longer: "Heat exchange liquid temperature (TH9 and TH10) 28.4°F ( -2°C)" *75 minutes: when indoor unit connection capacity 90% at 1 outdoor unit connection.
Condition : 2. Accumulated time 10 minutes: "Heat exchange liquid temperature (TH9 and TH10) Defrosting Start Judgment Temperature* And "During heat exchange liquid temperature keeps dropping "
*Defrosting Start Judgment Temperature(°F) = 0.8 x Outdoor temperature (°F) - 52.9 However, -17.7°F to 21.2°F If the calculated result is lower than -17.7°F, the judgment temperature is defined as -17.7°F If the calculated result is higher than 21.2°F, the judgment temperature is defined as 21.2°F (Defrosting start judgment temperature are determined by the outdoor temperature.)
*Defrosting Start Judgment Temperature(°C) = 0.8 x Outdoor temperature (°C) - 11.6 However, -27.6°C to - 6°C If the calculated result is lower than -27.6°C, the judgment temperature is defined as -27.6°C If the calculated result is higher than -6°C, the judgment temperature is defined as -6°C (Defrosting start judgment temperature are determined by the outdoor temperature.)
Condition: 3. Less than 10 minutes operation at outdoor temperature below 35.6°F (2°C) occured 20 times < Defrosting start condition >
