SIEMENS LME21.350C2 Oil/Gas Burner Control LME21 Series

The SIEMENS LME21.350C2 is a powerful and reliable burner control designed for single-stage oil or gas burners, offering a robust solution for industrial heating applications. This control unit stands out with its compact design, intuitive operation, and adherence to stringent safety standards. Key technical parameters include its suitability for single-stage operation, a voltage supply of 220-240V AC, and a frequency of 50/60 Hz, making it a versatile choice for various installations.

Product Specifications

| Feature                | Specification                 |

| :--------------------- | :---------------------------- |

| Product Series         | LME21 Series                  |

| Model Number           | LME21.350C2                   |

| Burner Type            | Single-stage Oil/Gas          |

| Voltage Supply         | 220-240 V AC                  |

| Frequency              | 50/60 Hz                      |

| Safety Class           | EN 298                        |

| Flame Monitoring       | Ionization probe or UV sensor |

| Operating Temperature  | -20 to +60 °C                 |

| Dimensions (W x H x D) | 147 x 102 x 60 mm             |

Core Features & Market Positioning

The SIEMENS LME21.350C2 distinguishes itself in the competitive burner control market through its robust safety features and straightforward integration. Its design prioritizes operational integrity, ensuring dependable performance in demanding industrial environments. The unit’s compliance with EN 298 safety standards underscores its reliability, a critical factor for plant managers and maintenance engineers. The LME21 series is positioned as a cost-effective yet high-performance solution for burner management, offering essential functionality without unnecessary complexity. Its market appeal lies in its ability to provide a secure and efficient control platform for a wide range of combustion equipment.

Key Application Scenarios

This burner control is ideally suited for a variety of single-stage combustion applications. It is commonly employed in industrial boilers, process heaters, and commercial heating systems where precise and safe control of oil or gas burners is paramount. Its versatility makes it a go-to component for HVAC contractors and system integrators working on new installations or retrofitting older equipment. The LME21.350C2's ability to manage a single-stage burner efficiently contributes to optimized fuel consumption and reduced emissions in applications such as:

  Industrial steam boilers  Hot water boilers for commercial buildings  Process air heaters  Drying ovens

Practical System Integration Guidance

Integrating the SIEMENS LME21.350C2 into an existing or new system is a streamlined process. The control unit features clearly labeled terminals for straightforward wiring of the burner, ignition transformer, fan, and safety devices like flame sensors. It typically requires connection to a mains power supply (220-240V AC) and an appropriate flame detection device, either an ionization probe or a UV sensor, which monitors the combustion process for safety. The unit’s plug-in design facilitates easy replacement and maintenance. For optimal performance, ensure the burner and its associated components are correctly sized and matched to the LME21.350C2's specifications. Referencing the detailed wiring diagrams provided in the product manual is essential for correct installation.

Operation and Risk Mitigation

Safe operation of the SIEMENS LME21.350C2 is facilitated by its inherent safety interlocks and diagnostic capabilities. The unit performs a pre-purge cycle to clear the combustion chamber of any residual gases before ignition, and a post-purge cycle after shutdown to cool the system. In the event of a flame failure or other operational anomalies, the control unit will immediately shut down the burner and indicate a fault. This fail-safe operation is critical for preventing hazardous conditions such as unburnt fuel buildup or flashbacks. Common troubleshooting involves checking power supply, burner ignition, fuel supply, and the integrity of the flame detection system. Fault codes, if displayed via an integrated indicator or connected diagnostic tool, provide specific insights into the nature of the issue, allowing for targeted corrective actions and minimizing downtime.

Scalability & Long-Term Value

While the SIEMENS LME21.350C2 is a robust standalone control for single-stage burners, its value extends through its integration into larger industrial automation systems. Siemens’ broader portfolio of industrial controls and automation solutions means that systems utilizing the LME21.350C2 can be expanded or integrated with SCADA or IIoT platforms for remote monitoring and data acquisition. The reliability and established performance of the LME21 series ensure long-term operational value, with readily available support and replacement parts within the Siemens ecosystem. This focus on compatibility and long-term support makes it a sound investment for facilities seeking dependable and future-proof combustion control.

Frequently Asked Questions

What is the primary function of the SIEMENS LME21.350C2?

It is a burner control for single-stage oil or gas flames. It manages ignition, flame monitoring, and safety shutdowns.

It ensures safe and efficient operation of the burner system. It complies with EN 298 safety standards.

This unit is vital for industrial boilers, heaters, and commercial heating systems. It provides reliable combustion control.

Can the LME21.350C2 be used with two-stage burners?

No, this model is designed exclusively for single-stage burners. Two-stage operation requires a different control unit.

Using it with a two-stage burner will result in improper functionality and safety risks. Always match the control to the burner stage requirement.

Refer to Siemens' LME range for controls suited to multi-stage or modulating burners.

What type of flame detection is compatible with the LME21.350C2?

It supports both ionization probes and UV flame detectors. Choose based on fuel type and environment.

The ionization probe is common for oil burners. UV detectors are versatile for gas and oil applications.

Ensure the detector is correctly wired and positioned for reliable flame sensing.

What voltage and frequency does the LME21.350C2 operate on?

It requires a 220-240V AC power supply. The compatible frequency is 50 or 60 Hz.

Ensure your local power supply matches these specifications for correct operation. Incorrect voltage can damage the unit.

This common voltage range makes it suitable for global installations.

How do I perform a system check on the LME21.350C2?

Follow the pre-ignition safety checks and burner startup sequence. Monitor for stable flame and proper purging.

Perform post-operation checks, ensuring the unit shuts down cleanly. Test safety interlocks periodically.

Refer to the official Siemens manual for detailed testing and commissioning procedures.

What are the typical error codes for the LME21.350C2?

Error codes indicate specific fault conditions. Common ones relate to flame failure or lockout.

Consult the product manual for a comprehensive list of codes and their meanings. Accurate diagnosis is key.

Proper troubleshooting of error codes ensures rapid resolution and system uptime.

What are the physical dimensions of the SIEMENS LME21.350C2?

The control unit measures approximately 147mm in width, 102mm in height, and 60mm in depth.

These compact dimensions allow for easy integration into control panels. Ensure adequate clearance for ventilation.

Its small footprint is advantageous in space-constrained installations.

Is the LME21.350C2 suitable for outdoor installations?

It is designed for industrial and commercial indoor environments. Outdoor use requires suitable weather protection.

Exposure to moisture, extreme temperatures, or direct sunlight can compromise its performance and lifespan.

Always install in a protected enclosure if there's a risk of environmental exposure.

What is the expected operating temperature range for this burner control?

The SIEMENS LME21.350C2 operates reliably within a temperature range of -20 to +60 degrees Celsius.

This wide range allows for use in many industrial settings. Extreme temperatures can affect electronic component performance.

Ensure proper ventilation if operating at the higher end of the temperature spectrum.

Where can I find the wiring diagram for the LME21.350C2?

The wiring diagram is typically found within the official SIEMENS LME21.350C2 product manual.

Always use the manual provided with your specific unit for accurate installation. Diagrams are also available on Siemens' support sites.

Correct wiring is crucial for safety and proper function of the burner control.