Sigma Control (original)
Sigma Control 1 and Sigma Control 2 are not interchangeable — the sensors, harness and panel cutout all change. Plan a panel rebuild, not a board swap.
Manufacturer
Kaeser
Display
Monochrome text LCD with function keys and status LEDs; industrial-PC based.
Years produced
~1998 – 2011. Superseded by Sigma Control 2.
Power supply
24 VDC internal from 230 VAC control transformer.
Ambient range
0 – 45 °C.
Protection rating
IP54 front.
Relay outputs
Main/star/delta, inlet valve solenoid, venting valve, dryer, common alarm.
Replaced by
Sigma Control 2
Used on
- Kaeser BSD / CSD / DSD / ESD (1998–2011)
- AS / SK / SM packages of that era
Features
- DUAL / QUADRO / VARIO / CONTINUOUS control modes
- Maintenance counters for filter, separator, fluid, motor bearings
- Base-load changeover for up to 4 units
Interfaces
- Profibus DP (option)
- Modbus RTU (option)
- Sigma Air Manager link
- Volt-free contacts
Sensor inputs
- Airend discharge temp (PT100)
- Internal pressure
- Network pressure
- Motor PTC
- Filter ΔP (option)
Fault code lookup
First checks
- Fluid level and cooler fouling
- Thermostatic valve
- PT100 ≈138.5 Ω at 100 °C
First checks
- PTC continuity cold
- Amp draw vs FLA
- Starts per hour over limit
First checks
- Swap two incoming legs
- Check phase monitor relay
First checks
- Inlet valve not closing
- Venting valve fault
- Sensor drift vs gauge
First checks
- Perform the kit, reset only that counter
Fault list is non-exhaustive and firmware-dependent. Always confirm against the controller’s on-screen help or OEM manual.
Sensor pin resistance & signal values
Pin-level resistance and signal values for the sensor types this controller uses. Works offline. De-energise the panel and lift one lead before ohming any element.
Wiring notes
- The controller is a hardened PC — pulling power without a controlled shutdown can corrupt the CF card holding parameters
- Profibus and sensor cabling must be routed clear of the starter compartment
Known issues & field notes
- Compact-flash parameter card degrades with age; symptoms are random parameter loss or a controller that will not boot
- Keypad membrane and LCD backlight are the two most common wear parts
Operator menu is open; service menus need a Kaeser service code issued by the dealer. No published universal code.
Manuals & literature
Kaeser — support portal
Manuals gated — request via local rep or parts portal
Your manuals
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