9. BACKUP OPERATION (EMERGENCY OPERATION)
This product offers backup modes of operation to tide over certain emergency situations. If a trouble occurs in
one of the compressors, it is possible to operate the system on an emergency basis by operating only the
remaining compressor, (compressor backup operation).
If one of the outdoor units fails in a combined outdoor unit system, the system can be operated on an
emergency basis by keeping only the remaining outdoor unit(s), (outdoor unit backup operation).
Perform backup operation setting in accordance with the procedure described below.
9-1. Note for Backup Operation
The method of backup operation differs according to the contents of trouble as shown in the table below.
Note 1:
If the compressor has failed due to a trouble in its motor coil (e.g. a layer short-circuit), do not perform
compressor backup operation because of severe oil degradation. It could damage other outdoor units.
Note 2:
Keep the number of backed-up outdoor units under compressor backup operation to one in the system
(single refrigerant line).
Contents of trouble
Method of backup operation
Setting procedure
Compressor backup (see Note 2)
Go to 9-2.
One of the compressors in the same unit fails (see Note 1)
Outdoor unit backup or cooling-
All the compressors in the same unit fail
season outdoor unit backup (see
Notes 1, 3, 4 and 5)
Go to 9-3. or 9-4.
A trouble occurs in a compressor motor coil (e.g. a layer short-circuit)
A trouble occurs in a refrigerating cycle part, fan or related part, or electrical part
A trouble occurs in a temperature sensor or pressure sensor
Note 3 :
Keep the total backup outdoor units lower or equal than 50% of the outdoor units in one system refrigerant line.
Note 5 :
It is possible to do backup operation even the system is connected with different chassis size and different weight
of outdoor units.
Failure
Backed-up
Outdoor Unit
Failure
Backed-up
Outdoor Unit
Prohibited
Example:
Failure
Backed-up
Outdoor Unit
Permitted
Example:
Failure
Backed-up
Outdoor Unit
Note 4 :
Count the outdoor unit that is having backup compressor operation as one operable outdoor unit.
The backup operation is still possible to do as long as the total backup outdoor units lower or equal than 50% of
total outdoor units.
Failured
Backed-up
Compressor
Failure
Backed-up
Outdoor Unit
Permitted
Example:
Failured
Backed-up
Compressor
Failure
Backed-up
Outdoor Unit
Permitted
Example:
Failure
Backed-up
Outdoor Unit
Backed-up
Outdoor Unit
Failure
Permitted
Example:
Backed-up
Outdoor Unit
Failure
Permitted
Example:
Backed-up
Outdoor Unit
Failure
Permitted
Example:
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