Outdoor Unit Operation Control; Compressor Operation Control; Operation Stop Condition; Compressor Output Pattern - Fujitsu AB12 Service Manual

5. OUTDOOR UNIT OPERATION CONTROL

5-1 COMPRESSOR OPERATION CONTROL

5-1-1 OPERATION STOP CONDITION

Compressor operation condition
When cooling requirement capacity or heating requirement capacity from either of the indoor units in the same
refrigerant system is input, the compressor operates.
But in the following case, the compressor operates in accordance with operation of each mode.
During 3 minute restart prevention operation
During compressor recovery operation
During deicing operation
Failure ( except for a part )
Defrosting
4-way valve 1 restart switching
Oil recovery
Under expansion valve initialization
At protective operation
Central discharge temperature protection
High pressure protection
Compressor stop condition
When all the indoor units in no "cooling requirement capacity" or "heating requirement capacity ", all the compressors
are stopped.
But, in the following case, the compressor operates in accordance with operation of each mode.
Defrosting
Oil recovery

5-1-2 COMPRESSOR OUTPUT PATTERN

The output pattern of a compressor is defined as shown below.
COMPRESSOR 1
OUTPUT PATTERN
Step 0
Step 1
Step 2
Step 3
Step 4
Step 5
Step 6
Step 7

5-1-3 3 MINUTES RESTART PREVENTION (3 MIN ST)

When the compressor is stopped, the compressor does not start on any condition for 3 minutes afterwards.
But, this function is excluded when defrosting, oil recovery is performed and the power is turned on.
Compressor output pattern
COMPRESSOR 2
(2HP) (4HP)
OFF OFF
ON OFF
OFF ON
ON ON
OFF
OFF
OFF
ON
ON
OFF
ON
ON
COMPRESSOR 3
(6HP)
OFF
OFF
OFF
OFF
ON
ON
ON
ON
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