LME21.350C1 Siemens Burner Control

Overview

The Siemens LME21.350C1 is a high-performance burner control unit designed for the startup and supervision of 1- or 2-stage gas or gas/oil burners. Part of the Siemens LME series, this microcomputer-based controller is engineered for intermittent operation in small to medium-capacity burners. It serves as a modern, digitally controlled replacement for legacy LGB and LMG series controls, providing enhanced reliability and safety through accurate signal handling. The unit ensures optimal combustion processes by managing the ignition sequence and monitoring flame stability in industrial and commercial HVAC systems.

Features

• Digital signal handling provides a highly accurate and repeatable control sequence
• Undervoltage detection ensures the system shuts down safely if power drops below operational levels
• Air pressure supervision includes a functional check of the air pressure switch during startup and operation
• Multicolor LED indicator provides clear status messages and diagnostic fault codes
• Electrical remote reset facility allows for convenient system management
• Limited number of repetition attempts enhances safety by preventing continuous recycling during a fault
• Controlled intermittent operation triggers a safety shutdown after 24 hours of continuous running

Specifications

• Model: LME21.350C1
• Mains Voltage: AC 120 V (+10% / -15%)
• Frequency: 50 to 60 Hz (+/- 6%)
• Power Consumption: 12 VA
• Prepurge Time (t1): 30 seconds
• Safety Time (TSA): 5 seconds
• Preignition Time: 4 seconds
• Protection Rating: IP40 (when properly mounted)
• Operating Temperature: -20 C to +60 C
• Weight: Approximately 160g

Applications

• Startup and supervision of 1- or 2-stage gas or gas/oil burners
• Forced draft burners for gaseous fuels in accordance with EN 676
• Atmospheric gas burners with or without fans
• Integration into gas trains for industrial boilers and commercial heating plants
• Replacement for Siemens LGB21.350A17 and LMG series burner controls (with appropriate ancillary units)