80
<Example of action when the pressure value is both above the upper limit value and below the lower limit value>
Upper-upper
limit value
Upper limit
value
Lower limit
value
Lower-lower
limit value
Compressor 1
Operation (load)
Stop
Operation (load)
Compressor 2
Operation (load)
Operation (unload)
Stop
Compressor 3
Operation (load)
Operation (unload)
Stop
Compressor 4
Operation (load)
Operation (unload)
④
①
A pressure value exceeds the upper-upper limit value. At the next control period (01 min), the compressor 1 will be switched to
the stop mode regardless of the adjustment operation time.
In addition, the compressor 2 with the next highest priority will be switched to the unloaded operating mode.
②
The compressor 1 and compressor 2 are switched to the stop mode and unloaded operating mode respectively.
③
Since the adjustment operation time is over, the compressor 2 is switched to the stop mode.
The compressor 3 with the highest priority in compressors with the loaded operating mode is targeted and switched to the
unloaded operating mode.
④
Since the adjustment operation time is over, the compressor 3 is switched to the stop mode.
Since the pressure value drops below the lower-lower limit value, at the next control period (04 min), the compressor 1 will be
switched to the loaded operating mode regardless of the adjustment operation time and start delay time.
⑤
Regardless of the adjustment operation time and start delay time, the compressor 1 is switched to the loaded operating mode.
The compressor 2 with the highest priority in compressors with the stop mode is targeted and it keeps standby mode until the
adjustment operation time is over.
⑥
Since the pressure value rises to the lower limit value or more, at the next control period (06 min), the control for compressor 2
will not be executed.
Furthermore, since the pressure value exceeds the upper limit value, at the next control period (06 min), the compressor 4 with
the highest priority will be switched to the unloaded operating mode.
⑦
The compressor 4 is switched to the unloaded operating mode.
③
②
①
⑤
⑥
⑦
<Example of action>
Adjustment operation time: 1 minute
Start delay time:
1 minute
Adjustment operation time
Start delay time
Measurement value for
determination
Pressure measured value
59 min
00 min
01 min
02 min
03 min
04 min
05 min
06 min
Control target at
the start of control
Priority
High
Low
