QRA51M Siemens Sensor

Overview

The Siemens QRA51M is a self-checking ultraviolet (UV) flame detector designed for the supervision of gas, oil, or dual-fuel flames. As part of the DETACTOGYR flame supervision system, it is specifically engineered for continuous operation or for burners that run for more than 24 hours without interruption. It features a side-viewing design, allowing for lateral light entry, which is ideal for specific burner mounting configurations where frontal viewing is not possible.

Features

• Self-checking mechanism with a rotating cylindrical shutter that interrupts UV radiation three times per second to verify the UV cell’s functionality
• Side-viewing (lateral incidence of light) design for specialized burner mounting
• Integrated synchronous motor suited for continuous operation
• Robust die-cast alloy housing with a quartz-glass lens to protect the internal cell
• Cooling air connection (3/8 inch tapping) to protect the sensor in high-heat areas or prevent soot buildup
• Outer light metal tube can be rotated 180 degrees for flexible installation

Specifications

• Detection Type: Ultraviolet (UV)
• Spectral Sensitivity: 190 to 240 nm
• Operating Voltage: AC 220–240 V or AC 100–110 V (depending on version)
• Operating Mode: Continuous Operation (Self-checking)
• Protection Rating: IP40
• Operating Temperature: -20 C to +50 C
• Weight: Approximately 0.75 kg
• Mounting: Clamping flange for mounting directly on the burner
• Compatible Control: Siemens LFE50 flame safeguard

Applications

• Supervision of gas flames and yellow or blue burning oil flames
• Continuous operation industrial burners (operating >24 hours)
• Use in DETACTOGYR flame supervision systems with LFE50 and LEC1 control units
• Burners requiring lateral light entry due to mechanical constraints