De Dietrich 300000673 safety box Honeywell DMG 991 mod.04

The control and safety unit (300000673) is designed to manage gas burners, including combined gas/diesel models. It operates using a microprocessor-based program to ensure stable burner performance regardless of voltage fluctuations, ambient temperature changes, or frequent start-up cycles. The built-in information system continuously monitors all operations, especially the start-up phase, and provides alerts for potential shutdowns. Even after a power loss, the unit retains data on the fault causes in its memory. The burner control unit ensures a high level of safety even during voltage drops. If the voltage falls below the allowable limit, the unit stops functioning and prevents automatic restart, ensuring the system remains safe under unstable electrical conditions. The undervoltage protection works both during burner ignition and normal operation. A key advantage of this unit is its microprocessor-controlled information system. It displays all events related to burner operation and flame control, continuously informing about the current working phase. Moreover, it helps identify start-up issues without requiring external diagnostic tools. The automatic diagnostics feature simplifies maintenance and reduces service costs. Fault analysis can be performed immediately or later, as error data is stored in the unit’s memory. Some design features of the control and safety unit (300000673) include: Microprocessor, electronic components, relay, and flame signal amplifier are placed on two circuit boards. The top of the housing includes a lockout/reset button with an integrated LED indicator and a central mounting screw. The S98 base is equipped with backup and auxiliary contacts, allowing for flexible cable connections. The unit is used in gas burners installed in De Dietrich boilers. Some compatible models include: Gas burner G 203/2 N Gas burner G 201/2 N Gas burner G 303-5 N 20 mbar Gas burner G 303-2 S Gas burner G 303-3 N (G303-3N)