Siemens Burner automation LME21.330C2

The Siemens LME21.330C2 is a burner control box (flame safeguard) for gas burners in industrial or commercial applications. It supports flame detection with ionisation, UV, or IR sensors and operates in intermittent cycle mode as a single-stage or two-stage gas burner control. It controls and drives the ignition transformer, fuel valve, and fan, while monitoring air pressure and verifying the air pressure switch. The unit features digital signal processing, undervoltage detection, remote reset signal, fault status indication, and manual reset. It locks out on flame failure. Because it is not interchangeable across series, verify the existing control's specifications before replacement.

Burner control boxes of this type are selected by matching the exact series and type designation of the original. Key parameters to compare are supply voltage, pre-purge and safety times, flame detection method, and base or plug pattern. These controls are not interchangeable across series even within the same brand; a mismatch in safety times or voltage creates a safety hazard. Before ordering, verify the existing control's specifications, particularly the safety time rating and the connector layout, to ensure a direct replacement.