Panasonic U-8MF2E8 Service Manual page 13

3. Compressor Control
3-2-4. 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,
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 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
3-4. Operating Frequency Range of Inverter Compressor
When one of the constant speed compressor mounted in the outdoor unit do not operate:
The inverter compressor can operate between 15Hz and 95Hz.
When all constant speed compressors mounted in the outdoor unit operate:
The inverter compressor can operate within the range in the table below.
Outdoor Unit Capacity
Min. frequency
Max. frequency
3-5. Forced Compressor Stop
Once a compressor stops, it will not start for a period of 3 minutes (3-minute forced OFF).
However, this does not apply when the compressor was forced to stop as the result of control operation during
the special controls (start control, defrost control, refrigerant oil recovery control, etc.)
> High-pressure sensor temperature +10°C
or
High-pressure sensor temperature +5°C
>
8 hp 10 hp 12 hp
15
66.1
66.8 82.0
1 - 5
unit: Hz
14 hp 16 hp
16
71.7 79.0
hp = horsepower
3WAY SYSTEM
Control Functions
1