Daikin VRV II-Q RQYQ8-48PY1B Service Manual page 58

Detailed Control Functions
2.4.3 Outdoor Unit Rotation
In the case of multi-outdoor-unit system, this outdoor unit rotation is used to prevent the compressor from
burning out due to unbalanced oil level between outdoor units.
[Details of outdoor unit rotation]
In case of multi-outdoor-unit system, each outdoor unit is given an operating priority for the control.
Outdoor unit rotation makes it possible to change the operating priority of outdoor units.
Thus, the system becomes free of compressors that stop over an extended period of time at the time of partial loading,
preventing unbalanced oil level.
[Timing of outdoor unit rotation]
• At the beginning of the starting control
• After oil return operation
OR
• After defrost operation
• When any of outdoor unit stops for a period of 20 minutes or more (in heating)
Example) The following diagram shows outdoor unit rotation in combination of 3 outdoor units. (in heating)
Starting
control
Outdoor unit
rotation
<In Heating>
Master Slave 1 Slave 2
Priority
1
* "Master unit", "slave unit 1" and "slave unit 2" in this section are the names for installation.
They are determined in installation work, and not changed thereafter. (These names are different from "master unit"
and "slave unit" for control.)
The outdoor unit connected the control wires (F1 and F2) for the indoor unit should be designated as main unit.
Consequently, the LED display on the main PCB for "master unit", "slave unit 1" and "slave unit 2" do not change.
<System with two outdoor units>
Previous time
This time
Next time
<System with three outdoor units>
Previous time
This time
Next time
One time after the next
48
Normal operation
Master Slave 1 Slave 2
Priority Priority Priority
1 2
Any of outdoor
unit stops for a
period of 20
Normal operation
minutes or more.
Priority Priority
2 3
Outdoor Unit 1 Outdoor Unit 2
Priority 1
Priority 2
Priority 1
Outdoor Unit 1 Outdoor Unit 2
Priority 1
Priority 3
Priority 2
Priority 1
3
Normal operation
Master Slave 1 Slave 2
Outdoor unit
Priority
rotation
3
Priority 2
Priority 1
Priority 2
Outdoor Unit 3
Priority 2 Priority 3
Priority 1 Priority 2
Priority 3 Priority 1
Priority 2 Priority 3
SiBE341027
Priority Priority
1 2
Function