Siemens QRB Series
Photoresistive Flame Detectors for Compact Gas & Oil Burners. Reliable visible light monitoring for heating systems.
What is the Siemens QRB Series?
The Siemens QRB Series is a family of photoresistive flame detectors designed for flame supervision in small to medium-capacity gas and oil burner systems. Unlike ultraviolet flame detectors, QRB models operate based on visible light detection. They measure changes in flame luminosity and transmit a signal to the burner control unit to confirm stable combustion.
The QRB Series is commonly used in compact burner systems where cost-effective and reliable flame monitoring is required.
Detection Principle
QRB flame detectors use a light-sensitive photoresistor to detect visible flame radiation.
- Flame Presence: Light intensity increases.
- Sensor Response: Electrical resistance decreases.
- Verification: Burner control unit confirms stability.
- Safety Action: If signal is lost, the system initiates shutdown.
Compared to UV-based detection, QRB is optimized for smaller burners and clean combustion environments, typically in residential or light commercial systems.
Typical Applications
QRB Series flame detectors are widely applied in:
- Compact gas burners
- Light oil burners
- Commercial heating systems
- Residential boiler units
- Small industrial heating equipment
They are frequently integrated with Siemens burner control units such as LMO, LME, and related safety modules.
Photoresistive
Sensitive to visible light radiation, ideal for standard yellow-flame oil and gas burners.
Compact Design
Small footprint allows easy integration into residential and light commercial burner housings.
Core Functional Characteristics
All QRB Series detectors share the following characteristics:
- Visible light flame detection
- Compact housing design
- Fast flame-on and flame-off response
- Designed for continuous burner operation
- Compatible with Siemens compact burner controllers
These detectors are optimized for stable detection in properly adjusted combustion systems with clear flame visibility.
Model Differentiation Within the QRB Series
QRB models may differ in:
- Cable length and connector type
- Mounting configuration
- Protection class
- Sensitivity level
These variations allow installation flexibility depending on burner design and housing geometry.
QRB Series Variants
| Model | Typical Use | Cable Type | Application Range |
|---|---|---|---|
| QRB1 | Compact Gas Burner | Fixed Cable | Residential & Commercial |
| QRB3 | Oil Burner Systems | Fixed Cable | Light Oil Applications |
| QRB4 | Extended Mounting Version | Connector Type | Flexible Installation |
Specific model selection should consider installation environment and control unit compatibility.
Integration & System Compatibility
QRB Series flame detectors are typically used with:
- Siemens LMO burner control units
- Siemens LME compact burner controllers
- Small gas and oil burner systems
- Commercial heating control assemblies
Note: They are not intended for high-capacity industrial burners requiring UV-based detection.
Positioning Within Siemens Flame Detection Systems
Within the Siemens combustion safety architecture:
- QRB Series: Visible light detection (compact burners)
- QRA Series: Ultraviolet detection (industrial burners)
- RAR Series: Infrared detection (oil burners)
QRB provides a cost-efficient and reliable solution for light-duty applications.
All Models
Standard Photoresistive
Extended Mounting
Selection Guide
Ideal for residential and light commercial gas burners.
Optimized for light oil burner systems with specific spectral sensitivity.
Features connector options for easier installation and replacement.
Burner Maintenance
Replacing a flame detector? Ensure you have the correct sensitivity and cable type for your burner model.
Contact SupportFrequently Asked Questions
What is the primary function of the Siemens QRB Series?
The Siemens QRB Series is designed to provide precise and reliable control for industrial combustion systems, ensuring optimal performance, safety, and energy efficiency across various heating applications.
How do I select the right model within the QRB Series?
Selecting the correct model depends on your specific application requirements, including operating voltage, required torque or capacity, and control logic (e.g., on-off vs. modulating). Refer to the model overview table above or contact our engineering team for technical assistance.
Are QRB Series components suitable for retrofitting existing systems?
Yes, Siemens designs the QRB Series with standardization in mind, making them excellent choices for both new installations and retrofitting older or legacy combustion systems to meet modern safety and emissions standards.