That’s why we use a hardwired interlock between the generator and the exhaust damper:
✅ Damper Open Command – Before the generator cranks, the actuator is driven to the open position.
✅ Proof of Open End Switch – A dry contact closes only when the damper is fully open.
✅ Start Permissive Relay – The generator start circuit is wired in series through this proof signal. If the damper is not open, the generator won’t start.
✅ Run Status Feedback – The generator controller provides a run status back to the BMS for monitoring.

👉 For projects with multiple dampers, their proof contacts are wired in series—ensuring that all dampers must be open before the generator can start.

👉Benefits of Proper Interlock Design
🔹Enhanced safety and compliance
🔹Protects generator from backpressure damage
🔹Ensures reliable startup during emergencies
🔹Provides clear status signals to operators and BMS

In critical applications like hospitals, data centers, and airports, this interlock isn’t just best practice—it’s essential.

🔧 Always remember: Safety interlocks must be hardwired. BMS should monitor, not control, these protective loops.