Compressor Sequence Operation - Fujitsu Airstage V series Service Manual

4-2-5 Compressor Sequence Operation

(1) Starting and stop control of the outdoor unit is performed by starting sequence and stop sequence
of the compressor. (Example: Three 14HP outdoor units are connected.)
But the following conditions shall be fulfilled.
(1-1) DC inverter scroll compressor is not placed in the sequence.
(1-2) If the DC inverter scroll compressor is in operation, the constant speed scroll compressor that starts first
and stops last has to be the one in the master unit.
(1-3) Difference in unit of operated compressor between the outdoor units is below 1 unit.
(1-4) Total capacity of operation of the master unit > Total capacity of operation of the slave compressor.
Master
1 6
Starting sequence
Stop sequence
0 0
Master
0 5
Starting sequence
Stop sequence 1 0
Master
0 4
Starting sequence
Stop sequence 2 0
Put off the sequence
by (1-2)
Master
0 3
Starting sequence
Stop sequence
3 0
Master
0 2
Starting sequence
Stop sequence 4 0
Master
0 1
Starting sequence
Stop sequence
5 0
Master
0 0
Starting sequence
Stop sequence 1 6
Move forward the
sequence by (1-3)
Master
0 0
Starting sequence
Stop sequence 2 7
Switch in sequence by (1-4)
Master
0 0
Starting sequence
Stop sequence
3 8
Slave1 Slave2
2 4 7 3 5 8
0 0 0 0 0 0
Slave1 Slave2
1 3 6 2 4 7
0 0 0 0 0 0
Slave1 Slave2
0 2 5 1 3 6
1 0 0 0 0 0
Slave1 Slave2
0 1 4 0 2 5
1 0 0 2 0 0
Slave1 Slave2
0 0 3 0 1 4
1 3 0 2 0 0
Slave1 Slave2
0 0 2 0 0 3
1 3 0 2 4 0
Slave1 Slave2
0 0 1 0 0 2
2 4 0 3 5 0
Slave1 Slave2
0 0 0 0 0 1
1 4 6 3 5 0
Slave1 Slave2
0 0 0 0 0 0
1 4 6 2 5 7
04-04
* Exception
Cooling : When 2 compressors of Master are operating,
and high pressure is high, constant speed
compressor of Slave is started.
Heating : When 2 compressors of Master are operating,
and low pressure is low, constant speed
compressor of Slave is started.
Compressor stops
Master
0 3
3 0
Switch in sequence by (1-3)
Slave1 Slave2
5 0 2 0 1 4
0 2 0 1 0 0