Brahma Combustion control unit CM381N.2 30185151

This is a microprocessor-based combustion control unit (control box) for atmospheric gas burners. It supports both single-stage and two-stage burners and is designed for intermittent (cyclic) operation. The unit has a pre-purge time of 30 s, a safety time of 5 s, and a waiting time of 30 s. It features a manual reset lockout that requires pressing a reset button on the housing after a flame failure.

Replacements for control boxes of this type are selected by matching the exact series and type designation, supply voltage, required safety time and pre-purge time, flame detection method, and electrical connection pattern (base or plug layout). The model code on the existing unit’s housing must be compared with that of the replacement; mismatched timing parameters create a safety hazard and units are generally not interchangeable across series even within the same brand. Before ordering, verify the connection pattern and the label on the old unit, as these details are essential for compatibility.

When the control does not receive a valid flame signal within the safety time, it enters lockout and the burner stops; the reset button must be pressed to restart. If the lockout recurs, the flame detection circuit or the control's reset mechanism may be faulty. Check the flame sensor and the supply voltage as part of the troubleshooting procedure.