Siemens QRB Series

Series Overview

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.

1. Flame Presence: Light intensity increases.
2. Sensor Response: Electrical resistance decreases.
3. Verification: Burner control unit confirms stability.
4. 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.

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.

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.