Daikin VRV II REYQ8MY1B, Service Manual

Page: 96 / 309

Si39-306 Other Control
Function 85
5. Other Control
5.1 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 the 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]
After oil return operation
After defrosting operation
At the beginning of the starting control
Example) The following diagram shows outdoor unit rotation in combination of 3 outdoor units.
* “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 master unit
Consequently, The LED display on the main PCB for “master unit”, “slave unit 1” and “slave
unit 2” do not change. (Refer to the page 87.)
or
Normal operation
Starting
control
Outdoor unit
rotation
Oil return operation
or defrosting
operation
Priority
1
Priority
2
Priority
3
Outdoor unit
rotation
Priority
3
Priority
1
Priority
2
Normal operation
Normal operation
Oil return operation
or defrosting
operation
Outdoor unit
rotation
Priority
2
Priority
3
Priority
1
Normal operation
Priority
3
Priority
1
Priority
2
Master Slave 1 Slave 2 Master Slave 1 Slave 2
Master Slave 1 Slave 2 Master Slave 1 Slave 2