Fujitsu Airstage VR-II Series Service Manual page 182

1-2. Backup operation when compressor of the slave unit #1 is broken.
[Procedure]
(Example: Three outdoor units are connected. the slave unit #1 is broken.)
1. Stop the operation, and turn off the all outdoor units. (Make sure the pressure equalization has been finished)
2. Fully shut off the 3-way valve (Liquid, High pressure gas, Low pressure gas ) of the broken slave unit #1.
3. Make up the system of two outdoor units (master and slave) by changing the DIP SW of the master unit.
Change the DIP SW 3-3/ 3-4 (Number of slave units connected) of the master unit,
from [ON/OFF](two units) to [OFF/ON](one unit).
4. Set up the slave unit #2 as Slave unit #1.
Change the DIP SW 3-1/ 3-2 (Outdoor unit address setting) of the slave unit #2,
from [ON/ OFF](slave unit #2) to [OFF/ ON](slave unit #1).
5. Change the DIP SW 5-1/ 5-2 (Number of outdoor unit) of the master unit and the slave
unit #2 (substitutional slave unit #1), from [ON/ OFF](three) to [OFF/ ON](two).
6. Turn on the units except the broken slave unit, and wait for more than 30 seconds.
(Do not turn on the broken slave unit)
7. It is ready for Backup operation.
Start operation as usual.
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