The KAESER SIGMA CONTROL 2 (SC2) is a machine-mounted compressor controller that brings industrial PC processing power to the task of compressed air regulation. Rather than reacting to a single pressure setpoint like a mechanical pressure switch, the SC2 continuously monitors compressed air demand and selects the most energy-efficient control mode for the current load condition. It is fitted as standard or optional equipment across KAESER's full range of rotary screw compressors, rotary screw blowers, reciprocating compressors, boosters, and rotary lobe blowers — and can be retrofitted to modernise older KAESER machines still running first-generation SIGMA CONTROL or third-party electromechanical regulation.

How do the five control modes differ?

Each mode addresses a different load profile. Continuous runs the compressor at constant speed, suitable for base-load machines operating near full capacity. Dual switches between load and idle at two programmable pressure setpoints, the simplest form of intermittent regulation. Quadro adds a second idle-speed setting for deeper part-load efficiency — the compressor runs at a reduced speed during periods of low demand rather than cycling between full-load and full-stop. Vario continuously varies motor speed via the integrated frequency converter (USS bus connection) to track demand in real time, providing the flattest pressure band and lowest specific power consumption. Dynamic is a compressor-size-dependent mode that optimises start-stop and load-idle transitions for machines with high cycling frequency. An integrated PI controller accepts a 0–20 mA process variable input — such as a dew-point sensor or flow meter — and adjusts compressor output to maintain a target process value rather than simply holding a pressure band.

What remote monitoring and security capabilities does the SC2 provide?

The built-in Ethernet port runs a web server that delivers a read-only dashboard of current operating data, pressure and temperature trend graphs, maintenance and fault messages, and event history — accessible from any browser on the plant network without installing proprietary software. For security, the RFID reader requires a programmed key fob or card to access the configuration menu on the local display; operators without a key can view operating data but cannot change pressure setpoints, control modes, or timer schedules. This touchless authentication is particularly valued in food, pharmaceutical, and clean-room compressed air installations where keypads and touchscreens accumulate contaminants. An SD card slot stores long-term operational data, accepts firmware updates, and can upload parameter sets for rapid controller replacement during field service.