LMO24.255C2 Siemens Burner Control

Overview

The Siemens LMO24.255C2 is a microprocessor-based burner control unit designed for the startup, supervision, and control of 2-stage forced draft oil burners in intermittent operation. Engineered to replace legacy LOA series oil burner controls, this compact unit manages pre-purge, ignition, and flame supervision for burners with an oil throughput of up to 30 kg/h. It features digital signal handling for accurate and reproducible control sequences, ensuring safe operation by monitoring voltage levels and initiating lockout if power drops below critical thresholds.

Features

• Microprocessor-controlled logic for precise timing and sequence management
• Multicolour LED signal lamp for real-time operational status and detailed fault diagnosis
• Integrated bridging contact for oil preheaters and monitoring of preheater startup time
• Electronic flame signal amplifier compatible with photoresistive QRB or blue-flame QRC sensors
• Under-voltage detection mechanism that prevents burner startup if mains voltage falls below AC 165 V
• Remote reset facility and digital interface (via OCI400) for PC-based diagnostics and parameter setting
• Impact-proof, heat-resistant, and flame-retarding black plastic housing

Specifications

• Model: LMO24.255C2
• Supply Voltage: AC 230 V (50/60 Hz)
• Pre-purge Time (t1): 25 seconds
• Safety Time (TSA): 5 seconds
• Pre-ignition Time (t3): 5 seconds
• Maximum Oil Throughput: Up to 30 kg/h
• Protection Class: IP40 (ensured by mounting)
• Operating Temperature: -20 C to +60 C
• Power Consumption: 12 VA
• Weight: Approximately 200g
• Dimensions: 91mm x 54mm x 62.5mm

Applications

• Supervision of 2-stage forced draft oil burners in residential and commercial heating systems
• Control of small to mid-size oil-fired boilers
• Integration into burner systems by OEMs requiring EN 230 compliant safety controls
• Replacement of legacy Siemens LOA24 and LOA26 oil burner control boxes
• Management of forced draft burners using yellow-burning or blue-burning oil flames