SIEMENS QRA10.C Ultraviolet UV Flame Detector Burner

The Siemens QRA10.C ultraviolet (UV) flame detector is a critical component for reliable burner management in industrial combustion systems. Its robust design and advanced technology deliver rapid flame detection, ensuring operational safety and efficiency. Key advantages include its high sensitivity to UV radiation emitted by flames, immediate response time, and suitability for a wide range of fuel types and combustion environments. The QRA10.C boasts an operating temperature range of -40 to +60 °C, a supply voltage of 20 to 30 V AC, and a switching capacity of 0.5 A at 250 V AC. Its compact dimensions (67 x 67 x 80 mm) and IP65 enclosure rating facilitate easy integration into demanding industrial settings.

Product Specifications

| Parameter         | Specification                                     |

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

| Detection Method  | Ultraviolet (UV) radiation                        |

| Operating Voltage | 20 to 30 V AC                                     |

| Power Consumption | 3 VA                                              |

| Temperature Range | -40 to +60 °C                                     |

| Ingress Protection| IP65                                              |

| Dimensions (H x W x D) | 67 x 67 x 80 mm                                   |

| Switching Capacity| 0.5 A at 250 V AC                                 |

| Housing Material  | Flame-retardant plastic                           |

| Cable Entry       | M16 x 1.5                                         |

Core Features & Market Positioning

The Siemens QRA10.C differentiates itself through its high-performance UV sensing technology, which offers superior flame detection capabilities compared to less sensitive flame scanners. Its ability to reliably detect flames across various burner types and fuels positions it as a versatile and dependable choice for plant operators. The device's robust construction and IP65 rating ensure resilience in harsh industrial environments, minimizing maintenance requirements and downtime. Market reviews often highlight its straightforward integration and consistent performance, making it a favored component in burner control systems where safety and operational continuity are paramount. This UV flame detector is engineered for applications requiring a direct and unambiguous flame signal.

Key Application Scenarios

The Siemens QRA10.C ultraviolet UV flame detector burner is extensively utilized in industrial combustion processes across numerous sectors. It is a standard component in the safe and efficient operation of industrial boilers, furnaces, and thermal oxidizers, commonly found in chemical plants, power generation facilities, and manufacturing operations. Its application extends to incinerators, kilns, and drying plants where precise flame monitoring is essential to prevent hazardous conditions and optimize fuel consumption. The detector's sensitivity to UV radiation makes it particularly effective for detecting gas, oil, and pulverized coal flames.

Practical System Integration Guidance

Integrating the Siemens QRA10.C UV flame detector into a burner management system (BMS) typically involves careful wiring and connection to the controller. The detector features a standard four-pin connection: pins 1 and 2 are for the AC supply voltage (20-30V AC), while pins 3 and 4 are for the internal relay output, which closes when a flame is detected. Proper grounding of the detector housing is crucial for safety and signal integrity. The QRA10.C is designed to be mounted on the burner housing or windbox, typically via a threaded flange, ensuring optimal viewing angle of the flame. Ensuring the viewing window is clean and unobstructed is vital for accurate detection. Referencing the specific burner management system's manual for interconnection diagrams and configuration settings is highly recommended for optimal setup.

Operation and Risk Mitigation

The Siemens QRA10.C operates by continuously monitoring the ultraviolet radiation emitted by a flame. When a flame is present, it emits UV light that strikes the detector's sensor, causing a change in electrical output. This change signals the connected burner management system to confirm the presence of a flame. To mitigate risks, it is crucial to ensure the detector is correctly installed and aimed at the flame, with an unobstructed view. Regular inspection of the viewing window for dirt or damage, and periodic testing of the detector's function as part of a scheduled maintenance program, are essential. Faults, such as a "no flame" signal when a flame is expected, or a "flame present" signal with no flame, indicate potential issues requiring immediate investigation.

Scalability & Long-Term Value

The Siemens QRA10.C UV flame detector offers excellent long-term value due to its robust design and compatibility with a wide range of Siemens burner control systems. Its integration into larger industrial automation platforms, including those supporting the Industrial Internet of Things (IIoT) and digital transformation initiatives, is straightforward through standard control signals. This allows for remote monitoring, data logging, and predictive maintenance capabilities when integrated with appropriate gateways and software. While the QRA10.C itself is a standalone component, its reliable performance and the availability of its successor models ensure that systems utilizing this technology can be maintained and upgraded efficiently, securing operational continuity and maximizing return on investment.

FAQs

What is the primary function of a Siemens QRA10.C UV flame detector?

The Siemens QRA10.C is designed to detect the ultraviolet radiation emitted by a flame. It provides a crucial signal to the burner management system, confirming the presence of a flame during combustion. This ensures safe and efficient burner operation by enabling appropriate control responses.

Its main purpose is to act as a safety interlock, preventing the burner from operating without a stable flame. This safeguards against fuel-rich conditions and potential explosions. The detector's rapid response time is critical for immediate feedback to the control system.

This UV flame detection technology is ideal for various fuel types, including gas and oil, by responding to the specific UV spectrum emitted during combustion. Proper aiming and maintenance are key for reliable long-term performance.

How does the Siemens QRA10.C UV flame detector work?

The detector contains a UV-sensitive element that reacts to ultraviolet light. When a flame is present, it generates UV radiation within a specific wavelength range. This radiation strikes the sensor inside the QRA10.C, causing it to generate an electrical signal.

This signal is then transmitted to the burner control unit or flame safeguard controller. The controller interprets this signal as confirmation of a stable flame. If no UV radiation is detected within a set time, the controller will initiate a safe shutdown sequence.

The device utilizes a built-in relay for signaling, which closes when UV radiation is detected. This electrical contact provides a direct and reliable indication of flame presence to the overall control system architecture.

What are the key technical specifications of the Siemens QRA10.C?

The Siemens QRA10.C operates on an AC supply voltage ranging from 20 to 30 volts. It has a power consumption of approximately 3 VA. The detector is rated for an operating temperature range of -40 to +60 degrees Celsius.

Its ingress protection rating is IP65, meaning it is protected against dust and low-pressure water jets. The dimensions of the unit are 67 mm in height, 67 mm in width, and 80 mm in depth.

The switching capacity of the internal relay is 0.5 A at 250 V AC. The housing is constructed from a flame-retardant plastic material, and it features an M16 x 1.5 cable entry for electrical connections.

Where is the Siemens QRA10.C UV flame detector typically used?

This UV flame detector is commonly deployed in industrial combustion applications such as boilers, furnaces, and thermal oxidizers. It is essential for ensuring the safe and reliable operation of these systems in power plants, chemical facilities, and manufacturing plants.

Its applications also extend to incinerators, kilns, and industrial drying equipment where precise flame monitoring is a critical safety and operational requirement. The detector is versatile enough for various fuel sources, including natural gas, oil, and pulverized fuels.

The QRA10.C's robust design makes it suitable for environments where dust, moisture, and varying temperatures are present, ensuring continuous performance in demanding industrial settings.

What are the advantages of using a UV flame detector like the QRA10.C?

UV flame detectors, such as the QRA10.C, offer rapid detection of flame presence by sensing the characteristic ultraviolet radiation emitted. This leads to faster response times for burner management systems, enhancing safety.

They are highly sensitive and can detect a wide range of flame types, including gas, oil, and solid fuels, across various combustion conditions. Their robust design, like the IP65 rating of the QRA10.C, ensures reliability in harsh industrial environments.

Compared to some other flame sensing technologies, UV detectors can be more cost-effective while still providing excellent performance for many standard industrial burner applications. Their straightforward operation simplifies integration and maintenance.

How is the Siemens QRA10.C installed and wired?

Installation typically involves mounting the detector on the burner housing or windbox, ensuring its viewing window has a clear line of sight to the flame. A threaded flange or bracket is commonly used for secure attachment.

Wiring connects the detector to the burner management system. Pins 1 and 2 are for the 20-30V AC power supply, while pins 3 and 4 provide the relay output signal that indicates flame presence. Proper grounding of the unit is essential.

For optimal performance and safety, it is critical to follow the specific wiring diagrams and installation guidelines provided in the Siemens technical documentation for the QRA10.C and the associated burner control system.

What is the recommended maintenance for the Siemens QRA10.C?

Regular visual inspection of the detector's viewing window is crucial to ensure it is clean and free from soot, dirt, or damage that could obstruct the flame signal. Periodic cleaning with a soft cloth may be necessary.

Functional testing of the QRA10.C should be performed as part of routine burner system maintenance. This involves verifying that the detector correctly signals flame presence and absence to the burner control unit.

Checking the integrity of electrical connections and the mounting of the detector are also important aspects of maintenance. Adhering to the manufacturer's recommended service intervals and procedures is key to ensuring long-term reliability.

Can the Siemens QRA10.C be used with different types of fuels?

Yes, the Siemens QRA10.C UV flame detector is suitable for use with a variety of fuels. It primarily detects the ultraviolet radiation emitted by flames, which is common to most combustion processes.

This makes it effective for burners firing natural gas, propane, fuel oil, and even some solid fuels like pulverized coal. The key is that the flame produces sufficient UV radiation for the detector to sense it reliably.

The specific effectiveness can depend on burner design and combustion characteristics, but generally, UV detection is a versatile choice for multi-fuel industrial burners.

What are common troubleshooting issues with the QRA10.C?

A common issue is a "flame lost" signal when a flame is actually present. This can be caused by a dirty or obstructed viewing window, improper aiming of the detector, or a failing UV sensor.

Conversely, a "flame present" signal when no flame exists might indicate a faulty relay or external UV interference. Ensuring proper wiring and shielding can help prevent such false signals.

Other issues could relate to the power supply (voltage too low or unstable) or problems within the connected burner management system. Always verify the detector's signal against the controller's diagnostics.

Is the Siemens QRA10.C compatible with modern IIoT systems?

While the QRA10.C is a standalone component, its standard relay output signal can be readily integrated into modern IIoT platforms. This is typically achieved by connecting the detector to a compatible PLC or gateway that digitizes and transmits the data.

These connected systems can then monitor flame status remotely, log operational data, and enable predictive maintenance strategies based on burner performance trends. This enhances overall system intelligence and efficiency.

Therefore, the QRA10.C, when part of a larger integrated control architecture, contributes to the overall digital transformation and IIoT capabilities of an industrial combustion system.