Siemens Photocell Detector QRA2 Series
Siemens QRA2 Series UV Flame Detectors are designed to monitor gas and oil flames in industrial combustion systems. Utilizing ultraviolet flame detection technology, they provide flame signals to compatible Siemens burner controls, including selected LFL, LGB, LME and LMV series. Suitable for industrial boilers and heating equipment, the QRA2 Series supports reliable flame supervision in intermittent burner operation.
Product Details
Siemens Photocell Detector QRA2 Series
Siemens QRA2 Series – UV Flame Detectors
Siemens QRA2 Series UV Flame Detectors are designed for flame supervision in industrial gas and oil burner applications. These detectors monitor ultraviolet radiation emitted by combustion flames and provide flame signals to compatible Siemens burner controls.
The QRA2 Series is suitable for industrial boilers, heating equipment and combustion systems requiring flame supervision during intermittent burner operation.
Operating Principle
The Siemens QRA2 uses a UV-sensitive detector cell that responds to ultraviolet radiation within the wavelength range of 190–270 nm. When sufficient UV radiation reaches the cell, an electrical current is generated in the flame detection circuit.
The UV cell is designed not to respond to glowing refractory materials, daylight or normal boiler room illumination. However, external UV sources, including welding equipment and ignition sparks, may cause false flame signals. Proper installation is therefore essential.
Key Features
- Ultraviolet flame detection technology
- Suitable for gas and oil flame supervision
- Can be used for ignition spark proving
- Metallized plastic housing to reduce static charging
- Designed for direct burner mounting
- Normal and high-sensitivity versions available
- Optional mounting flange and clamp configurations
- Compatible with selected Siemens burner controls
Applications
- Industrial gas burners
- Industrial oil burners
- Industrial boiler systems
- Industrial heating equipment
- Combustion flame supervision systems
Product Selection
Selecting the appropriate Siemens QRA2 detector requires consideration of detector sensitivity, burner control compatibility, mounting arrangement, ambient temperature and installation conditions.
Compatibility with the specific burner controller must be verified using the relevant Siemens technical documentation.
Note: The QRA2 Series is intended for intermittent burner operation. Installation, commissioning and servicing must be performed by qualified personnel.
Technical Specifications
Siemens QRA2 Series Technical Specifications
| Brand | Siemens |
|---|---|
| Product Series | QRA2 Series |
| Product Type | UV Flame Detector |
| Detection Principle | Ultraviolet radiation detection |
| UV Wavelength Range | 190–270 nm |
| Fuel Compatibility | Gas and oil |
| Operating Mode | Intermittent operation |
| Safety Class | Class II |
| Degree of Protection | IP20; IP40 with suitable cable entries, such as AGG09 |
| Operating Temperature | -20 to +60 °C |
| Relative Humidity | Less than 95% RH |
| Installation Altitude | Maximum 2,000 m above sea level |
| Average UV Cell Life | Approximately 10,000 hours at temperatures up to 50 °C |
| Weight | Approximately 46 g |
| Mounting Position | Optional |
| Recommended Cable | H05VV-F 2 × 0.75 mm² |
| Housing Material | Metallized plastic |
| Compatible Burner Controls | LGB2/LGB4 with AGQ1, LFL, LFE1, LFE10, LMG with AGQ2, LME21/LME22/LME39 with AGQ3, LME7, LMV2/LMV3 and LMV5 with AGQ1 |
Siemens QRA2 Series Model Variants
| Model | Sensitivity | Mounting Accessories | Terminal Cover |
|---|---|---|---|
| QRA2 | Normal | Without | Black |
| QRA2(1) | Normal | Rounded flange and clamp | Black |
| QRA2(2) | Normal | Straight flange and clamp | Black |
| QRA2.9 | Normal | Without | Black |
| QRA2M | High | Without | Green |
| QRA2M(1) | High | Rounded flange and clamp | Green |
| QRA2M(2) | High | Straight flange and clamp | Green |
Note: The QRA2.9 features a heat-resistant housing designed to withstand ambient temperatures up to 200 °C for a short duration of only a few seconds. This is not a continuous operating temperature rating.
Dimensions
Documents & Downloads
Frequently Asked Questions
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