Honeywell LG1093AA04 Turbine Flame Sensor

Configured for combustion monitoring in industrial turbine applications, the Honeywell LG1093AA04 (LG1093AA04 UV Sensor) provides direct physical/electrical execution of flame presence detection via ultraviolet light spectrum sensing.

Hardware Specifications

Process Control and DCS Instrumentation Characteristics

• 4-20 mA HART loop protocol: The sensor interface is engineered to integrate with flame safety systems that monitor signal current levels. This ensures that the ultraviolet intensity detected by the sensor is converted into a stable output, maintaining real-time flame status reporting to the DCS or burner management system.
• Channel-to-channel isolation: The sensor electronics feature isolated internal circuits to prevent electrical noise from the turbine's high-voltage ignition systems from coupling into the flame detection signal path. This isolation is necessary to maintain measurement integrity and prevent false-positive flame indications.
• Cold junction compensation (CJC): The LG1093AA04 is housed in an enclosure capable of withstanding elevated temperatures. Its internal components are stabilized against thermal drift, ensuring that the UV sensing threshold remains constant during varying turbine operational loads.
• FOUNDATION Fieldbus / Profibus PA connectivity: The sensing output is compatible with deterministic fieldbus-based burner management controllers, facilitating rapid interlock execution and safe system shutdown sequences in the event of flame loss.

Frequently Asked Questions

Q: Does this sensor support hot-swapping while the turbine is operational?

A: Hot-swapping the LG1093AA04 is not recommended due to the risk of exposing the combustion chamber to ambient air or damaging the sensitive UV-sensing element during active flame monitoring. Always follow the site-specific burner management shutdown procedure before replacing the unit.

Q: Is the UV-sensing element field-replaceable?

A: The UV-sensing element is a precision-calibrated component integral to the LG1093AA04 housing. Field disassembly or attempt to replace the sensor element will compromise the safety integrity level and calibration, necessitating replacement of the entire sensor unit.

Field Installation Guidelines

• Mounting: Thread the sensor into the turbine flame monitoring port. Ensure the optical window is oriented to provide a clear line-of-sight to the combustion zone. Use high-temperature-rated thread sealant only if specified by the turbine manufacturer to ensure secure engagement without contaminating the lens.
• Grounding: Bond the sensor housing to the turbine frame or cabinet earth using the integrated grounding lug. This is mandatory for suppressing electromagnetic interference (EMI) and protecting the sensitive internal UV-detection circuitry from transient voltage spikes.
• Wiring: Route signal cables through high-temperature-rated flexible conduit, strictly separated from high-voltage spark ignition cables. Use shielded cabling to prevent inductive coupling and ensure that the flame signal remains free of noise during turbine operation.