Panasonic U-8ME1E81 Service Manual page 13

3. Compressor Control
Inverter Compressor
Shorter operating time Longer
operating time
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
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,
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.
Multiple constant speed compressors start every second.
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.
-Delay start condition of constant speed compressor
Maximum discharge temperature of
inverter compressor in whole system
Minimum discharge temperature of
inverter compressor in whole system
Priority order flow of all compressors
Constant Speed Compressor 2
Shorter operating time Longer
< High pressure sensor temperature +10°C
or
< High pressure sensor temperature +5°C
Control Functions-Outdoor Unit
Constant Speed Compressor
Constant Speed Compressor 3
Shorter operating time Longer
operating time
1 - 5
2WAY SYSTEM
1
operating time