Siemens LGK16.622A27 Gas Burner Control Unit

The Siemens LGK16.622A27 is a high-performance, microprocessor-controlled gas burner control unit designed for the automation, monitoring, and safety regulation of medium to high-capacity forced draft gas burners. This module functions at the hardware tier to execute precise burner sequencing loops, manage air-to-fuel automation, and enforce fail-safe operational parameters. Engineered specifically for continuous-operation systems, it incorporates integrated self-checking flame supervision circuitry to prevent hazardous unburned fuel accumulation.

Hardware Specifications

Burner Sequence Execution & Safety Timings

• Pre-Purge Air Displacement and Damper Interlocking During start command initialization, the control unit enforces a strict 65-second pre-purge timer ($t1$). The internal logic interfaces directly with external air pressure switches and motorized air damper actuators to confirm adequate combustion air volume. It verifies the damper drives to the fully open position before starting the purge cycle, ensuring any residual combustible gas pockets within the furnace chamber are completely cleared before ignition spark tracking begins.
• Self-Checking Flame Supervision and Safety Shutdowns For safety in continuous-operation plants (running un-interrupted for more than 24 hours), the LGK16.622A27 uses an active, self-checking flame signal amplifier loop. The internal monitoring system runs regular, sub-second test routines that check for false flame indications, sensor degradation, or component short-circuits. If a flame signal failure manifests during active running, or if the flame fails to light during the critical 2-second safety time ($TSA$), the unit locks out fuel delivery valves within milliseconds.

Frequently Asked Questions

Q: What specific fault indicator states manifest on the faceplate lockout window if an air pressure failure occurs during pre-purging?

A: If the external air pressure switch fails to close within the designated startup window, or drops open during the 65-second pre-purge ($t1$), the control sequence halts immediately. The integrated mechanical indicator disk snaps into a lockout state and displays a specific visual fault code symbol (typically an air symbol or indicator line), closing the safety interlock and turning on the remote alarm terminal register.

Q: Can an ionization rod and a UV flame detector be wired into the LGK16.622A27 control unit simultaneously?

A: No, the control unit's internal self-checking input matrix is optimized for a single terminal configuration depending on the selected burner type. Wiring both sensor types into the amplifier circuit simultaneously alters the tracking impedances, corrupts the self-checking logic parameters, and will trigger an immediate startup lockout fault.