Compressor Control - Panasonic U-8MF2E8 Service Manual

3. Compressor Control

3-1. Compressors Mounted in the Outdoor Units
[U-8MF2E8, U-10MF2E8, U-12MF2E8, U-14MF2E8, U-16MF2E8]
Compressor 1
Installed
compressor
Compressor 2
1
Top view
8 HP
DC Inverter
3-2. Compressor Selection Rules
3-2-1. Priority Order of Inverter Compressor and Constant Speed Compressor
Priority order of inverter compressor is higher than that of constant speed compressor.
* However, when the inverter compressor stops because of protection control or forced stop, etc., a constant speed
compressor operates while the inverter compressor has stopped.
3-2-2. Priority Order of Inverter Compressors
The priority order of the inverter compressor with the least operating time is high.
* The comparison is made among inverter compressors other than ones stopped because of protection control or
forced stop.
Shorter operating time
3-2-3. Operating Compressors
All cooling mode
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.
All heating mode or mixed cooling/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.
DC Inverter Rotary
Constant speed Scroll
10 HP
DC Inverter
Constant speed 5HP
Priority order flow of all compressors
No backup status
Inverter Compressor
Longer operating time
8 hp 10 hp
10HP 10HP
– –
12 HP 14 HP
DC Inverter
Constant speed 5HP
Constant Speed Compressor
Shorter operating time
1 - 4
3WAY SYSTEM
Control Functions
12 hp 14 hp
10HP 10HP
5 HP 5 HP
hp = horsepower
16 HP
DC Inverter DC Inverter
Constant speed 6HP
Longer operating time
16 hp
10HP
6 HP