LME71.000A2 Siemens Burner Control

Overview

The Siemens LME71.000A2 is a microprocessor-based burner control basic unit designed for the startup and supervision of multistage or modulating forced draft gas or oil burners in intermittent operation. It serves as a central flame safeguard, ensuring combustion safety by monitoring flame signals and controlling safety shutoff valves. Engineered for medium to high-capacity industrial thermal processes, the LME71 system is modular, requiring a plug-in program module (PME71 series) to define its specific functional characteristics, such as purge timing and pilot sequences.

Features

• Digital signal handling provides an accurate and repeatable control sequence for burner operations
• Integrated multicolor LED signal lamp and 3 x 7-segment display for clear service, error, and status information
• Built-in BC interface allows for seamless connection to a remote AZL2 display or PC for advanced diagnostics
• Comprehensive air pressure supervision includes a functional check of the air pressure switch during startup and operation
• Enhanced safety functions include under-voltage detection and a Proof of Closure (POC) input to monitor gas valve positions
• Durable design with a rated lifetime of 250,000 startup cycles, approximately 10 years of service under normal heating conditions
• Support for electrical remote lockout reset to facilitate easy system recovery from safe states

Specifications

• Model: LME71.000A2
• Operating Voltage: AC 230 V (50/60 Hz)
• Power Consumption: Approximately 12 VA
• Protection Rating: IP40 (ensure adequate protection in the final installation)
• Temperature Range: -20 C to +60 C (-4 F to +140 F)
• Weight: Approximately 490g (1.08 lbs)
• Flame Detection: Supports ionization probes or UV flame detectors (QRA2, QRA4, or QRA10)
• Humidity: <95% r.h. (non-condensing)

Applications

• Supervision of forced draft gas or oil burners in accordance with EN 267 and EN 676 standards
• Industrial thermoprocessing equipment applications complying with EN 746-2 safety requirements
• Management of 1-stage, 2-stage, or modulating burners in HVAC and boiler systems
• Linkageless fuel-air ratio control via air damper actuators or PWM-controlled fan motors
• Atmospheric gas burner systems requiring intermittent operation and precise safety timings