LME76.000A2 Siemens Flame Safeguard

Overview

The Siemens LME76.000A2 is a high-performance, microprocessor-based burner control unit designed for the supervision of forced draft burners of medium to large capacity. As a critical safety component, it manages the startup and monitoring of multistage or modulating burners, ensuring efficient and safe combustion. The LME76 series is engineered for flexibility, allowing for the control of fuel-air ratios via air damper actuators or pulse width modulated (PWM) fans. This specific “A2” model is configured for 230V AC operation and is suitable for both continuous and intermittent operation, providing reliable flame safeguard functionality in demanding industrial and commercial thermal process plants.

Features

• Microprocessor-controlled digital signal handling ensures an accurate and repeatable control sequence
• Designed for continuous operation, with support for intermittent operation when specifically parameterized
• Multicolor LED signal lamp provides clear status and fault messages for simplified diagnostics
• Integrated BC interface allows for connection to an AZL2 display unit or OCI460 cloud gateway for advanced monitoring
• Undervoltage detection and electrical remote lockout reset facility enhance system safety and maintenance
• Air pressure supervision includes a functional check of the air pressure switch during startup and operation
• Programmable parameters allow for customized purge times, safety times, and pilot operation to suit specific burner requirements
• High endurance design with a rated lifetime of approximately 250,000 burner startup cycles

Specifications

• Model: LME76.000A2
• Supply Voltage: AC 230 V (50/60 Hz)
• Power Consumption: Approximately 3 VA
• Protection Rating: IP40 (when mounted)
• Operating Temperature: -20 C to +60 C
• Weight: Approximately 486 g (0.486 kg)
• Safety Level: SIL3 classification (depending on flame supervision method and parameterization)
• Dimensions: 180 mm (Height) x 120 mm (Width) x 52.6 mm (Depth)
• Flame Supervision: Supports Ionization probes or UV flame detectors (such as QRA2, QRA4.U, or QRA10)

Applications

• Supervision of 1-stage or 2-stage forced draft burners for gaseous and liquid fuels
• Modulating forced draft burners with pneumatic or mechanical fuel-air ratio control
• Industrial thermoprocessing equipment in accordance with EN 746-2
• Forced draft burners for gaseous fuels in accordance with EN 676
• HVAC and boiler systems requiring continuous flame monitoring and safety shut-off functions
• Integration by original equipment manufacturers (OEMs) into complex gas trains and combustion systems