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Siemens Flame sensor QRA2

SKU QRA2 Brand Siemens

Photos

Key specifications

Detection principle	ultraviolet flame detector
Cable length	1000 mm
Country of origin	Germany
Fuel	gas and liquid fuel
Detection principle	ultraviolet radiation
Electrical connection	locking connector
Catalogue article numbers	884.208.004
Device type	flame detector
Operating temperature	-20 °C
Spectral sensitivity	UV range (190-270 nm)

all specifications (10) ↓

209.17 EUR

190.15EUR

in stock · 3

incl. 21% VAT · 157.15 EUR excl. VAT · shipping calculated at checkout

Worldwide shipping from stock
Original manufacturer part
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Description

The Siemens QRA2 is an ultraviolet flame sensor intended for flame supervision on burners firing gas or liquid fuel. It works by continuously detecting the ultraviolet radiation emitted by the flame, with a spectral sensitivity of 190–270 nm. This detector has a 1000 mm cable and uses a locking connector for its electrical connection. Its operating temperature range is rated from -20 °C, and it is compatible with Siemens LFL, LAL, LGK, and LGB burner control systems.

Further details

Application	boilers, industrial furnaces, and other installations where flame monitoring is important
Compatible Control Type	Siemens LFL, LAL, LGK, LGB burner controls
Design Features	compact housing protected against vibration and overheating
Line Of Sight	direct line of sight to the flame is required
Output Signal	signal to burner control confirming that combustion has started
Performance features	high sensitivity and accurate response even at minimum flame level
Purpose	automatic monitoring of the presence of a flame in the combustion chamber
Safety Function	stops fuel supply if flame is lost
Typical Failure Modes	contaminated window, aged UV cell, cracked or broken sheath

Choosing and fitting

When selecting a replacement UV flame sensor of this type, compare spectral sensitivity (UV range), response time, cable length, connector type, and mounting sleeve or flange. The sensor must have an unobstructed line of sight to the flame, and its viewing angle and distance must suit the burner geometry. Ensure the electrical connection and mounting arrangement are compatible with the existing burner control.

Signs of failure

UV flame sensors commonly fail due to a contaminated viewing window (soot or oil film), an aged UV cell producing a weak signal, or a cracked or broken sheath. When failure occurs, the burner control does not receive a flame signal within the safety time and locks out. Check the sensor window for dirt, test the signal strength, and inspect for physical damage.

Fits equipment

Siemens LFL, LAL, LGK, LGBSiemens LFLSiemens LALSiemens LGKSiemens LGB

All specifications

Detection principle	ultraviolet flame detector
Cable length	1000 mm
Country of origin	Germany
Fuel	gas and liquid fuel
Detection principle	ultraviolet radiation
Electrical connection	locking connector
Catalogue article numbers	884.208.004
Device type	flame detector
Operating temperature	-20 °C
Spectral sensitivity	UV range (190-270 nm)

Part numbers

SKU	QRA2
Additional article	884.208.004