5 Design and Function
5.1 STC and OFC/SFC machine types
STC: Machine with star-delta start
Machines with star-delta start operate at mains frequency with a speed determined by the belt
drive translation. The flow rate depends on the working pressure and, possibly, the options of the
specific machine.
OFC/SFC: Machine with frequency converters
Machines with frequency converters (FC) operate with variable speeds, regardless of the mains
frequency applied. The flow rate depends on the respective speed, the working pressure and, pos‐
sibly, the options of the specific machine.
STC: Sections of this manual with this symbol apply solely to machines with star-delta start.
OFC/SFC: Sections of this manual with this symbol apply solely to machines with frequency-
converter (FC).
All other sections apply to both machine types.
5.2 The controller
SIGMA CONTROL 2 controls, regulates, monitors, and protects the machine.
All parameters needed to operate KAESER blowers can be set and displayed using the controller.
Various user-dependent password mechanisms protect the parameters.
Components
SIGMA CONTROL 2 has the following components:
■ Main Control System (MCS):
─ Industrial PC
─ Software for the control, regulation, and monitoring of the machine, for the display and mod‐
ification of settings and for communication.
─ User interface with backlit display, touch keys, LEDs, and interfaces.
─ Radio Frequency Idenfication (RFID):
Identification with RFID Equipment Card
─ Slot for customer interface; optional communications module
─ SD card slot for SD/SDHC cards:
Manual loading of updates with an SC card, reading or recording process data
■ Input-Output-Module (IOM):
Modules with digital and analogue inputs and outputs with autonomous power supply
5
Design and Function
5.1
STC and OFC/SFC machine types
20
Service Manual Controller
SIGMA CONTROL 2 BLOWER ≥ 4.0.X
No.: 901700 14 E
