Siemens UV Flame Detectors QRA4 Series
Product Description
Siemens QRA4 Series UV Flame Detectors for Industrial Burners
Siemens QRA4 Series ultraviolet flame detectors are designed to supervise gas and oil burner flames in industrial combustion equipment. When connected to compatible Siemens burner control units, they provide flame presence signals during burner operation.
Flame Detection Principle
The QRA4 detects ultraviolet radiation generated by gas and oil flames within the 190–270 nm wavelength band. Its UV-sensitive element responds to sufficient flame radiation and produces an electrical signal that can be evaluated by the connected burner controller.
The sensing element does not respond to daylight or glowing firebricks within the combustion chamber. QRA4 flame detectors are intended for intermittent burner operation.
Key Features
- Ultraviolet sensing technology for flame supervision
- Detects gas flames and oil flames burning yellow or blue
- Supports ignition spark proving
- UV sensitivity range of 190–270 nm
- Robust aluminum detector housing
- Front-facing flame sensing arrangement
- IP54 enclosure protection when correctly installed
- Normal-sensitivity and high-sensitivity configurations
- Designed for selected Siemens burner management controls
Available QRA4 Models
- QRA4.U: Standard-sensitivity ultraviolet flame detector
- QRA4M.U: High-sensitivity ultraviolet flame detector
Industrial Applications
Siemens QRA4 detectors are used for flame monitoring in industrial boilers, gas-fired burners, oil burners, process heating equipment and combustion systems fitted with supported Siemens burner controls.
Installation and Maintenance Requirements
Install the detector where it can receive sufficient ultraviolet radiation from the supervised flame. Route its electrical wiring separately from other circuits, especially high-voltage ignition leads, to reduce interference.
The UV sensing cell is permanently installed within the detector housing and is not available as a separately replaceable component. At the end of the UV cell's usable life, replace the complete flame detector assembly.
Important Safety Note: Confirm compatibility with the specific Siemens burner control and follow the manufacturer's installation and safety requirements. Installation, wiring and servicing must be undertaken by qualified technicians.
Specifications
Siemens QRA4 Series – UV Flame Detector Technical Specifications
| Manufacturer | Siemens |
|---|---|
| Equipment Category | UV Flame Detector |
| Available Models | QRA4.U / QRA4M.U |
| Siemens Article Numbers | BPZ:QRA4.U / BPZ:QRA4M.U |
| Sensing Method | Ultraviolet (UV) |
| UV Detection Band | 190–270 nm |
| Detector Sensitivity | QRA4.U: Normal / QRA4M.U: High |
| Applicable Flame Types | Gas Flames / Yellow- and Blue-Burning Oil Flames |
| Permitted Operating Mode | Intermittent Operation |
| Enclosure Material | Aluminum |
| Flame Viewing Direction | Frontal Illumination |
| Ingress Protection | IP54 (when properly mounted) |
| Electrical Safety Class | Class II (Double-Insulated) |
| Maximum Combustion Chamber Pressure | 150 mbar |
| Ambient Operating Temperature | -20 to +60 °C |
| Permissible Relative Humidity | Less than 95% RH |
| Maximum Installation Elevation | 2,000 m Above Sea Level |
| Mounting Orientation | Optional (Any Orientation) |
| Typical UV Cell Operating Life | Approximately 10,000 Hours at Max. +50 °C |
| Approximate Weight | 180 g |
| Connection Cable Length | Approximately 1.8 m |
| Detector Mounting Thread | 3/4"-14NPSM |
| Protective Conduit Connection Thread | 1/2"-14NPSM |
| Available Accessories | AGG02 / AGG04 / AGG15 |
Siemens Burner Control Compatibility – QRA4.U vs QRA4M.U
| Burner Controller | QRA4.U | QRA4M.U |
|---|---|---|
| LFL | Compatible | — |
| LFE1 / LFE10 | Compatible | — |
| LFS1 | Compatible | Compatible |
| LGB2 / LGB4 + AGQ1 | Compatible | — |
| LME21 / LME22 + AGQ3 | Compatible | — |
| LME39 + AGQ3 | Compatible | — |
| LME41 / LME44 + AGQ3 | Compatible | — |
| LME71 / LME72 / LME73 | Compatible | — |
| LMV26.300Ax + AGM60.1 | Compatible | Compatible |
| LMV27.100Ax | Compatible | Compatible |
| LMV36.520Ax + AGM60.4 | Compatible | Compatible |
| LMV37.4 | Compatible | Compatible |
| LMV5 + AGQ1 | Compatible | — |
Technical Note: Compatibility depends on the exact burner control version and specified accessories. The dash (—) identifies combinations not listed as compatible in the referenced Siemens data sheet.
Product Specifications
Siemens QRA4 Series – UV Flame Detector Technical Specifications
| Manufacturer | Siemens |
|---|---|
| Equipment Category | UV Flame Detector |
| Available Models | QRA4.U / QRA4M.U |
| Siemens Article Numbers | BPZ:QRA4.U / BPZ:QRA4M.U |
| Sensing Method | Ultraviolet (UV) |
| UV Detection Band | 190–270 nm |
| Detector Sensitivity | QRA4.U: Normal / QRA4M.U: High |
| Applicable Flame Types | Gas Flames / Yellow- and Blue-Burning Oil Flames |
| Permitted Operating Mode | Intermittent Operation |
| Enclosure Material | Aluminum |
| Flame Viewing Direction | Frontal Illumination |
| Ingress Protection | IP54 (when properly mounted) |
| Electrical Safety Class | Class II (Double-Insulated) |
| Maximum Combustion Chamber Pressure | 150 mbar |
| Ambient Operating Temperature | -20 to +60 °C |
| Permissible Relative Humidity | Less than 95% RH |
| Maximum Installation Elevation | 2,000 m Above Sea Level |
| Mounting Orientation | Optional (Any Orientation) |
| Typical UV Cell Operating Life | Approximately 10,000 Hours at Max. +50 °C |
| Approximate Weight | 180 g |
| Connection Cable Length | Approximately 1.8 m |
| Detector Mounting Thread | 3/4"-14NPSM |
| Protective Conduit Connection Thread | 1/2"-14NPSM |
| Available Accessories | AGG02 / AGG04 / AGG15 |
Siemens Burner Control Compatibility – QRA4.U vs QRA4M.U
| Burner Controller | QRA4.U | QRA4M.U |
|---|---|---|
| LFL | Compatible | — |
| LFE1 / LFE10 | Compatible | — |
| LFS1 | Compatible | Compatible |
| LGB2 / LGB4 + AGQ1 | Compatible | — |
| LME21 / LME22 + AGQ3 | Compatible | — |
| LME39 + AGQ3 | Compatible | — |
| LME41 / LME44 + AGQ3 | Compatible | — |
| LME71 / LME72 / LME73 | Compatible | — |
| LMV26.300Ax + AGM60.1 | Compatible | Compatible |
| LMV27.100Ax | Compatible | Compatible |
| LMV36.520Ax + AGM60.4 | Compatible | Compatible |
| LMV37.4 | Compatible | Compatible |
| LMV5 + AGQ1 | Compatible | — |
Technical Note: Compatibility depends on the exact burner control version and specified accessories. The dash (—) identifies combinations not listed as compatible in the referenced Siemens data sheet.
Company Information
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