Back Up Operation; Method Of Backup Operation - Fujitsu Airstage VR-II Series Service Manual

4-4 SERVICE INFORMATION
SERVICE INFORMATION
Backup Operation
Details :
Backup operation is the operating method of replacing compressor while the system is running.
Compressor can be replaced without stopping the system.
In backup operation, cooling and heating capacity is decreased by the capacity
of the separated outdoor unit.
The work procedure is as follows.
4-4-1 Backup operation

1. Method of backup operation

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