KAESER KOMPRESSOREN SX, Service Manual, Page: 34 / 122

4.6 Operating modes and control modes
4.6.1 Operating modes
The machine operates in the following modes:
■ LOAD:
The inlet valve is open. The airend delivers compressed air to the system.
The drive motor runs under full load.
■ IDLE:
The inlet valve is closed. The minimum pressure/check valve shuts off the oil separator from the
air system. The oil separator tank is vented.
A small volume of air circulates through the bleed hole in the inlet valve, through the airend and
back to the inlet valve via the venting valve.
The compressor motor runs without load and draws little current.
■ STANDSTILL:
The inlet valve is closed. The minimum pressure/check valve shuts off the oil separator from the
air system. The oil separator tank is vented.
The compressor motor is stopped.
■ MODULATING:
With the help of a control valve (modulating controller), the degree of opening of the inlet valve
is continuously varied in relation to the actual air demand. The airend delivers compressed air to
the system.
The load and power consumption of the drive motor rises and falls with the air demand.
The regulating valve is factory set. The setting should not be changed without consultation with
KAESER Service.
4.6.2 Control modes
Using the selected control mode, the controller switches the compressor motor according to definite
rules (the control mode) between the various operating modes in order to compensate for air being
drawn off by consumers and maintain the machine's working pressure between the preset cut-in and
cut-out pressures.
The SIGMA CONTROL BASIC can work with the following control modes:
■ DUAL
■ QUADRO
■ MODULATING control
Energy-efficient control modes for various applications:
Application Recommended
control mode
Compressed air station with one machine or several machines with compa‐
rable delivery
QUADRO
Machine for peak load in a compressed air station DUAL
Machine for intermediate load in a compressed air station QUADRO
Machine for basic load in a compressed air station QUADRO
Tab. 30 Energy-efficient control modes
The SIGMA CONTROL BASIC control unit is factory set to QUADRO control mode unless specifically
ordered otherwise.
4 Design and Function
4.6 Operating modes and control modes
24
Service Manual Screw Compressor
SX SIGMA CONTROL BASIC
9_6919 04 E
Option C1
Option C1