Siemens Burner automation LME21.230C2

This burner automation control box is designed for single-stage and two-stage forced-draught burners. It has a supply voltage of 230 V at 50–60 Hz, consumes 12 W, requires a 10 A fuse, and offers IP40 protection. The timing sequence comprises a waiting time of 2.5 s, a pre-purge time of 20 s, a pre-ignition time of 2 s, a safety time of 3 s, and a post-ignition time of 2.5 s. It features a manual reset lockout safety mechanism.

For a control box of this type, selection must be based on the exact series and type designation, supply voltage, pre-purge and safety times, and the flame detection method. Always verify the pin layout and base pattern to ensure a mechanical match with the existing wiring base. Control boxes of this kind are typically not interchangeable across series, even within the same brand, so substitution must follow the manufacturer’s specifications.

A control box of this kind locks out if no flame is detected within the safety time, and then requires a manual reset. Once locked out, the burner remains out of service until the reset is performed.