SIEMENS QRA2(1) UV Flame Sensor QRA2 Series Burner

The Siemens QRA2(1) UV Flame Sensor is a critical component for reliable burner control in industrial applications, ensuring safe and efficient combustion processes. This highly sensitive sensor detects ultraviolet radiation emitted by flames, providing a rapid and accurate signal for burner management systems. Its robust design and advanced technology offer distinct advantages, including fast response times, high reliability, and a wide operating temperature range. Key technical parameters of the QRA2(1) include its spectral sensitivity, which is optimized for flame detection, and its fail-safe design that ensures operational integrity. The QRA2 series, specifically the QRA2(1) variant, is engineered for demanding environments, making it a preferred choice for Original Equipment Manufacturers (OEMs) and system integrators seeking dependable flame monitoring solutions.

Product Specifications

| Feature                     | Specification                               |

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

| Flame Detection             | Ultraviolet (UV) radiation                  |

| Spectral Sensitivity        | 190-270 nm                                  |

| Response Time               | < 1 s (typical)                             |

| Operating Temperature Range | -40 to +60 °C (-40 to +140 °F)              |

| Voltage                     | 24 V AC / DC                                |

| Current Consumption         | < 5 mA                                      |

| Housing Material            | High-grade plastic                          |

| Protection Class            | IP 40                                       |

| Connection Type             | Plug-in connection                          |

| Mounting                    | Direct mounting onto burner                 |

| Certification               | CE, UL, CSA                               |

Core Features & Market Positioning

The Siemens QRA2(1) UV Flame Sensor distinguishes itself through its rapid response time, crucial for preventing hazardous situations by quickly shutting down fuel supply in case of flame failure. Its design leverages solid-state technology for enhanced durability and a long operational lifespan, reducing maintenance requirements. Compared to other flame detection technologies, UV sensors like the QRA2(1) are particularly effective in a broad range of combustion applications, unaffected by steam or dust that can interfere with other sensor types. This reliability positions the QRA2(1) as a premium component for burner manufacturers and industrial plant operators who prioritize safety and continuous operation. Its integration into Siemens' comprehensive burner control portfolio further solidifies its market standing.

Key Application Scenarios

The Siemens QRA2(1) finds extensive application in various industrial combustion systems. It is a standard component in gas and oil burners used for boilers, furnaces, and process heaters across industries such as power generation, chemical processing, and manufacturing. Its ability to detect the characteristic UV emissions from both gas and oil flames makes it versatile for dual-fuel burners. The sensor is also utilized in incineration plants and industrial ovens where precise flame monitoring is paramount for operational efficiency and safety compliance. System integrators frequently specify the QRA2(1) for new installations and as a replacement part in existing burner management systems due to its compatibility and proven performance.

Practical System Integration Guidance

Integrating the Siemens QRA2(1) UV Flame Sensor into an industrial control system is straightforward, typically involving a direct connection to a burner control unit or safety module. The sensor features a standard plug-in connection, simplifying wiring and reducing installation time. For optimal performance, the QRA2(1) must be mounted directly onto the burner housing, ensuring it has a clear line of sight to the flame. It is crucial to observe the specified mounting orientation and ensure the sensor's viewing angle is not obstructed. The sensor's output is a simple electrical signal that the control unit interprets to confirm flame presence or absence. Always refer to the specific burner control unit’s manual for detailed wiring diagrams and configuration settings related to the QRA2(1).

Operation and Risk Mitigation

The Siemens QRA2(1) operates by continuously monitoring for ultraviolet radiation emitted by a burning flame. Upon detecting this radiation within its operational spectrum, the sensor generates an electrical signal indicating flame presence. If the flame extinguishes or is not detected within a specified timeframe, the sensor's signal changes, prompting the burner control system to initiate safety procedures, such as shutting off fuel flow and purging the combustion chamber. To mitigate risks, ensure the sensor is correctly installed and the viewing window is kept clean to maintain optimal sensitivity. Regular maintenance checks, as per manufacturer guidelines, are essential to prevent operational failures. Potential issues, like a lack of signal, could stem from a dirty sensor, improper wiring, or a complete absence of flame.

Scalability & Long-Term Value

The Siemens QRA2(1) UV Flame Sensor offers excellent long-term value due to its robust construction and compatibility with a wide range of Siemens burner control systems and other industry-standard platforms. While the QRA2(1) itself is a direct-acting component, its integration within a modular burner management system allows for scalability. Modern industrial facilities can leverage its reliable performance as a foundation for upgrading to more advanced digital control and monitoring solutions, including Industrial Internet of Things (IIoT) integration, through compatible control architectures. This ensures that investments in flame safety remain relevant and adaptable to evolving automation strategies.

Frequently Asked Questions (FAQs)

Q1: What is the primary function of the Siemens QRA2(1) UV Flame Sensor?

The Siemens QRA2(1) UV Flame Sensor is designed to detect ultraviolet radiation emitted by flames. This detection is crucial for ensuring safe and efficient combustion in industrial burners. It provides a rapid signal to burner management systems, enabling immediate action if a flame is lost.

This sensor is essential for safety interlocks, preventing the accumulation of unburned fuel. Its primary role is to confirm flame presence, a critical parameter for automated combustion control sequences.

Its UV sensitivity allows it to reliably monitor flames from various fuel sources, including natural gas and oil, in a wide array of industrial applications.

Q2: What are the key advantages of using the Siemens QRA2(1) over other flame sensors?

The QRA2(1) offers a fast response time, typically under one second, which is vital for safety. It boasts high reliability due to its solid-state UV detection technology.

Unlike some other sensors, it is generally unaffected by steam or dust that might be present in the combustion environment. This makes it suitable for more challenging industrial settings.

Its robust design and wide operating temperature range ensure dependable performance in demanding conditions, minimizing downtime and maintenance needs.

Q3: What technical specifications are most important for the Siemens QRA2(1)?

The spectral sensitivity range (190-270 nm) is critical for accurately detecting UV flame radiation. The response time of less than one second is vital for rapid safety responses.

The operating temperature range of -40 to +60 °C ensures functionality in diverse environmental conditions. Voltage (24 V AC/DC) and low current consumption (< 5 mA) are important for system compatibility.

The IP 40 protection class indicates its resistance to solid objects, suitable for many industrial enclosures. Its plug-in connection simplifies installation.

Q4: In which industrial applications is the Siemens QRA2(1) commonly used?

This sensor is widely used in gas and oil burners for boilers and furnaces in power plants and manufacturing. It's also found in process heaters and industrial ovens where consistent flame is critical.

Incineration plants utilize the QRA2(1) for safe waste combustion monitoring. Its versatility makes it a standard component for dual-fuel burners across many sectors.

The QRA2(1) is a preferred choice for OEMs building new combustion equipment and for maintaining existing industrial burner systems.

Q5: How is the Siemens QRA2(1) typically installed and integrated into a system?

Installation involves direct mounting onto the burner housing, ensuring a clear view of the flame. A plug-in connection simplifies electrical wiring to the burner control unit.

It's essential to follow the specific burner control unit's manual for accurate wiring diagrams and configuration settings. Proper mounting orientation is key for optimal detection.

The sensor's output signal is directly interpreted by the control system to confirm flame presence or absence, triggering appropriate safety sequences.

Q6: What are common operational issues or troubleshooting tips for the Siemens QRA2(1)?

If no signal is detected, first check for a clean sensor viewing window and ensure proper wiring. Verify that a flame is actually present and emitting UV radiation.

Incorrect mounting or obstructions to the viewing angle can also cause signal loss. Ensure the sensor is firmly seated and aligned with the flame.

Refer to the burner control unit's diagnostics for error codes. The QRA2(1) itself has a fail-safe design, so a lack of signal usually points to external factors.

Q7: Does the Siemens QRA2(1) have specific safety features to consider?

The QRA2(1) is designed with a fail-safe principle, meaning it will signal a flame loss if it malfunctions or if the flame is absent. This is crucial for safety interlocks.

Its rapid response time is a key safety feature, allowing for immediate fuel shut-off in case of flame failure. This prevents dangerous gas accumulation.

Always ensure the sensor is used in conjunction with an appropriate burner management system that interprets its signal and executes safety protocols correctly.

Q8: What is the expected lifespan and maintenance schedule for a Siemens QRA2(1)?

With its solid-state construction, the QRA2(1) generally offers a long operational lifespan. Specific lifespan depends heavily on the operating environment and duty cycle.

Routine maintenance typically involves visual inspection and cleaning of the sensor's viewing window to ensure optimal UV detection. This should be part of regular burner system servicing.

Consult the Siemens documentation or your burner manufacturer for recommended maintenance intervals and procedures for your specific application.

Q9: Can the Siemens QRA2(1) be used with different types of fuels?

Yes, the QRA2(1) is suitable for detecting flames from a variety of fuels, including natural gas, propane, and various fuel oils. Its UV sensitivity covers the typical emissions from these combustion processes.

The key is the presence of ultraviolet radiation from the flame itself, regardless of the specific fuel source. This makes it a versatile component for dual-fuel or multi-fuel burners.

Always ensure that the flame characteristics of the specific fuel being used produce sufficient UV radiation within the sensor's detection range for reliable operation.

Q10: How does the QRA2(1) sensor contribute to energy efficiency in combustion systems?

By ensuring immediate flame detection and stable combustion, the QRA2(1) helps maintain optimal burner performance. This prevents inefficient operation or flameouts.

Accurate flame monitoring allows burner control systems to precisely regulate fuel and air supply, leading to more complete combustion and reduced fuel waste.

Reliable flame confirmation reduces the need for excessive safety margins in burner operation, potentially allowing for more efficient control strategies and fuel savings.