BOGE Operating instructions for C 15 series screw compressors
Page 19
Product description
2.3
Compressor control
2.3 Compressor control
Network pressure
For the compressor, the pressure downstream of the check valve is termed
network pressure. The control system switches the compressor on and off dur-
ing operation depending on the network pressure.
Operating states
All screw compressor controls are based on three basic operating states:
1. Load operation
–
The compressor delivers its maximum amount of compressed air.
–
It consumes its maximum energy.
2. Idling operation
–
The compressor runs but does not deliver any compressed air.
–
It consumes approx. 75% less energy than in load operation.
–
When compressed air is required, it switches to load operation with out
delay.
–
Idling operation reduces switching frequencies which can damage the
drive motor, and reduces wear of the system.
3. Standstill ready for operation
–
The compressor is standing still but ready for operation.
–
When compressed air is required, it switches automatically to load
operation.
Operating modes
The two most important operating modes are achieved by combining the three
operating states:
1. Intermittent operation
In intermittent operation the energy balance is perfect.
–
The compressor operates in load operation.
–
Upon reaching the switch-off pressure p
max
the compressor switches
to standstill. It does not consume any energy.
–
Once the pressure has dropped to the switch-on pressure p
min
the com-
pressor switches back to load operation.
2. Continuous operation
Continuous operation limits the drive motor switching cycles and reduces
wear to the system.
–
The compressor operates in load operation.
–
Upon reaching the switch-off pressure p
max
the compressor switches to
idling operation.
–
Once the pressure has dropped to the switch-on pressure p
min
the com-
pressor switches from idling operation back to load operation.
