Siemens LME Series

Series Overview

The Siemens LME Series is a family of compact burner control units designed for automatic sequencing and safety supervision of gas and oil burners. The LME platform integrates ignition control, flame supervision, safety timing, and automatic shutdown logic into a single compact module.

It is widely used in commercial and light industrial burner systems where reliable combustion safety and structured start-up control are required.

Role Within the Combustion Control Architecture

In a complete burner system, the LME Series acts as the central safety controller. It coordinates:

• Pre-purge timing
• Ignition sequence
• Flame verification
• Continuous flame supervision
• Automatic shutdown in case of fault

Unlike simple relay-based controls, LME units use structured timing logic to ensure compliance with combustion safety standards.

Typical Applications

LME Series burner control units are commonly applied in:

• Gas-fired commercial burners
• Light oil burner systems
• Dual-fuel compact burners
• Commercial boiler systems
• Packaged burner assemblies

They are particularly suited for small to mid-capacity burners requiring standardized safety control.

Core Functional Characteristics

All LME models share the following operational structure:

• Automatic burner start sequence
• Integrated ignition transformer control
• Flame monitoring compatibility
• Lockout on flame failure
• Pre-purge and safety timing control
• Compact plug-in design

The control unit ensures that fuel supply is only permitted when safe combustion conditions are verified.

Flame Detection Compatibility

The LME Series can be used with compatible flame detection technologies, depending on burner configuration:

• QRB Series – Photoresistive (visible light) detection
• RAR Series – Infrared detection for oil burners
• Selected compatible flame sensors depending on model type

This flexibility allows the LME platform to adapt to various fuel types and burner designs.

Model Differentiation

Although sharing the same control philosophy, LME models may differ in:

• Fuel type configuration (gas, oil, dual-fuel)
• Safety timing sequences
• Electrical connection layout
• Ignition supervision configuration
• Application classification

Model selection must match burner capacity and required safety timing logic.

Selection Guide

When selecting an LME control unit:

• Confirm burner fuel type
• Verify compatible flame detector
• Check required pre-purge timing
• Ensure proper ignition configuration
• Confirm electrical compatibility

Proper configuration ensures reliable automatic burner start-up and safe shutdown in case of flame failure.

Integration Within Burner Systems

In a typical burner system architecture:

1. LME Burner Control Unit
2. Ignition Transformer
3. Flame Detector (QRB / RAR)
4. Gas Valve or Oil Solenoid Valve

The LME unit supervises the entire ignition and combustion safety process.

Positioning Within Siemens Combustion Systems

Within the Siemens combustion control portfolio:

• LME Series → Compact burner control units (commercial/light industrial)
• LDU Series → Industrial burner control units
• LMV Series → Advanced burner management systems

LME represents the compact and standardized safety control solution within this hierarchy.