Panasonic CU-3E18EBE - Outdoor Unit Operation

8.5. Outdoor Unit Operation
8.5.1. Room Temperature Control
8.5.1.1. Cooling, Soft Dry and Heating Operations
1. Immediately after the compressor has started up during an ongoing operation, the initial frequency is determined on the basis
of the information obtained from the heat exchanger capacities of the indoor units (thermostat ON) and the airflows set by their
remote controls.
2. During an ongoing operation, the difference between the temperature set in each of the rooms and the room temperature is
detected, the total load is calculated, and the compressor frequency is determined on the basis of this information.
3. When one room turns the thermostat OFF while two or more indoor units are operating, the automatic expansion valve closes
to restrict the flow of refrigerant, the compressor control is temporarily suspended, and both the initial frequency and total load
are determined again.
4. When the thermostat is turned OFF during 1-room operation, the outdoor unit´s compressor and fan stop. (The outdoor unit’s
fan stops 60 seconds after the compressor.)
5. It takes about 180 seconds for the compressor to be restarted after it has stopped. (Re-start control)
8.5.1.2. Deice Operation Control <Heating>
Outline Heat Pump Only
Defrosting is carried out by the cooling cycle (reverse cycle). The defrosting time or outdoor heat exchanger
temperature must be more than its fixed value when finishing.
Detail Conditions for Starting Defrost
The starting conditions must be made with the outdoor air temperature and heat exchanger temperature.
Under the conditions that the system is in heating operation, 6 minutes after the compressor is started and
more than 38 minutes of accumulated time pass since the start of the operation or ending the defrosting.
Conditions for Canceling Defrost
The target heat exchanger temperature as the canceling condition is selected in the range of 4°C<Te<12°C
according to the air temperature as the following formula.
The target heat exchanger temperature=-(45/65)(ambient temperature)+14
The defrost operation surely operates in 120 seconds after the start. (A
→
B)
After then the defrost operation stops at the following conditions.
1. When the heat exchanger temperature reaches the target heat exchanger temperature. (B
→
C)
2. When 650 seconds have passed after the start even if the heat exchanger temperature does not reaches
the target heat exchanger temperature. (C)
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