Panasonic U-20ME1E81, Service Manual

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1 - 5
2WAY SYSTEM
Control Functions-Outdoor Unit
1
3. Compressor Control
3-2-5. Operating compressors
-Cooling operation
All the inverter compressors operate when the system starts.
The constant speed compressors operate according to those priority orders when the load of air conditioner
becomes large.
* Some inverter compressors might stop after the system starts when the load of the air conditioner becomes
very small and ambient temperature is 10°C or more.
-Heating operation
At least, one inverter compressor operates when the system starts.
The other compressors operate according to those priority orders when the load of air conditioner becomes
large.
3-2-6. stopping compressors
-Situation in which multiple compressors stop
All compressors stop at the same time when all indoor units stop or defrosting operation is done.
*The stop of the compressor might shift for about ten seconds by the time lag of the communication between
outdoor units.
-Situation in which compressors stop in order of priority
-Delay start condition of constant speed compressor
The compressor with lower priority order stops when the load of air-conditioning decreases.
*The last compressor to stop operating is the inverter with the shortest amount of operating time.
3-3. Delay start of each compressor
To decrease the load of power-supply facility, it is possible to delay start of each compressor.
3-3-1. Delay start of compressor in the same system
When the inverter compressor and the constant speed compressor start at the same time, the inverter starts first,
3-3-2. Delay start of constant speed compressor
When the outdoor temperature is low and the following condition exists, constant speed compressor will be delay
start.
and the constant speed starts at least five seconds later.
*Depending on the operating states, the constant speed compressor might not start for 60 seconds after the
inverter compressor starts.
Maximum discharge temperature of
inverter compressor in whole system
High pressure sensor tempe10°C
or
<
Minimum discharge temperature of
inverter compressor in whole system
High pressure sensor tempe5°C <
Multiple constant speed compressors start every second.
Inverter Compressor Constant Speed Compressor
Constant Speed Compressor 2 Constant Speed Compressor 3
Shorter operating time Longer
operating time
Shorter operating time Longer
operating time
Shorter operating time Longer
operating time
Priority order flow of all compressors
SM830204-05_2WAY SYS.indb 5 2015/01/21 16:59:58