LME21.330C1 Siemens Burner Control

Overview

The Siemens LME21.330C1 is a high-performance, microcomputer-based burner control designed for the startup and supervision of 1- or 2-stage gas burners in intermittent operation. Engineered for small to medium capacity applications, this control unit ensures a precise control sequence through digital signal handling. It is widely used by original equipment manufacturers (OEMs) for integration into gas-fired equipment, providing critical safety functions such as undervoltage detection and air pressure supervision. The LME21 series is designed to be a direct housing replacement for legacy LGB and LMG burner controls, facilitating easy upgrades and maintenance.

Features

• Digital signal processing ensures an accurate and repeatable control sequence
• Undervoltage detection automatically shuts down the system if voltage drops below safe levels
• Air pressure supervision includes a functional check of the air pressure switch during startup and operation
• Multicolor LED provides clear indication of fault status and operational messages
• Electrical remote reset facility allows for convenient system recovery after a lockout
• Limitation of the number of repetitions prevents excessive restart attempts in fault conditions
• Controlled intermittent operation triggers a safety shutdown after a maximum of 24 hours of continuous operation

Specifications

• Model: LME21.330C1
• Mains Voltage: AC 120 V (50/60 Hz)
• Power Consumption: 12 VA
• Pre-purge Time (t1): 30 seconds
• Safety Time (TSA): 3 seconds
• Flame Supervision: Ionization probe or QRA flame detector with AGQ3 ancillary unit
• Protection Rating: IP40 (when integrated correctly)
• Operating Temperature: -20 C to +60 C
• Weight: Approximately 160 g (unit only)

Applications

• Supervision of 1- or 2-stage gas burners in commercial and industrial heating systems
• Forced draft gas burners conforming to EN 676 standards
• Atmospheric gas burners with or without fans conforming to EN 298
• Integration into boilers, furnaces, and thermal process plants
• Suitable for use in intermittent operation cycles where the burner is shut down at least once every 24 hours