What safety interlock should be in place for a flame rig controlled by DMX?

• A. An automatic interlock that prevents ignition if safe conditions are not met; the system should shut down the fuel if the flame sensor fails or if the control signal is invalid.
• B. A manual switch that allows ignition regardless of safety conditions.
• C. A timer-based interlock that only checks after ignition.
• D. A temperature-based interlock that never inhibits ignition.

Answer: (A)

When a flame rig is controlled by DMX, you need a fail-safe, automatic interlock that prevents ignition unless all safety conditions are verified and can shut off the fuel if something goes wrong. This means the system should automatically stop the fuel supply if the flame sensor detects a fault or if the DMX signal is invalid or lost. Having an automatic interlock that is hard-wired to the fuel control keeps safety independent of operator action and ensures a safe state even during a fault or signal glitch.

Why this is the best approach: it provides a true fail-safe mechanism. If safety conditions aren’t met, there’s no ignition, and if the flame safety device or control signal fails, the interlock shuts down the fuel to prevent a dangerous unattended flame. In contrast, a manual switch that allows ignition regardless of safety conditions bypasses protections, a timer-based interlock that only checks after ignition could permit hazardous lighting, and a temperature-based interlock that never inhibits ignition might fail to prevent unsafe pre-ignition conditions.