Mike Dolt Enterprises
Mike Dolt Enterprises
User: noeernlat, Location: Washington State
Asked on: Sunday, April 24, 2011 at 11:37 pm EDT
Answered on: Tuesday, May 14, 2024 at 4:35 am EDT
Question: Well I wired my first commercial fire suppression system and I have an inspection tomorrow. Here is what I did and you knowledged folks tell me if I should be worried. I have a 220 V exhaust, 120V Make up air and 120V hood lights. I got 3 NO contactors, 1 NO micro switch, 1NC micro switch, and a common. So I ran a 120v control circuit to a Two pole switch that switches the exh and mua, the mua runs to the single NO micro switch and from there to the NO contactor. The ex runs straight from the 2 pole switch to the contactor. I have a single pole switch for the hood lights and the same 120V control circuit powers it , then runs to the same micro switch NO (there is only one NO micro switch) which then goes to the contactor. I can't seem to understand how when the system is activated, it will shut down lights, mua, but leave the exh running. Any insight would be greatly appreciated. Thank you.
Based on your description, it seems that you have wired the system correctly to shut down the lights and make-up air, but keep the exhaust running when the fire suppression system is activated. Here's how the system should work
When the System is Activated:
1. The NO microswitch is activated by the fire suppression system.
2. This triggers the NO contactor for the make-up air, which opens and shuts down the make-up air fan.3. The NO contactor for the hood lights also opens due to the NO microswitch, shutting down the lights.
4. However, the exhaust fan contactor is not connected to the NO microswitch. Therefore, it remains closed and the exhaust fan continues to run.
Reason for Keeping Exhaust Running
In a fire suppression system, it is often desirable to keep the exhaust fan running. This is because the exhaust fan helps to remove smoke and harmful gases from the space, creating a safer environment for occupants and firefighters. By shutting down the make-up air and lights, the system can focus on exhausting the smoke and gases without introducing additional air or light into the space.
Inspection Tips
Verify the wiring diagram
Make sure that your wiring matches the approved wiring diagram for the system.
Test the system
Activate the fire suppression system and verify that the make-up air and lights shut down, while the exhaust fan continues to run.
Check for proper operation
Ensure that the exhaust fan is operating at the correct speed and that there are no obstructions in the exhaust ductwork.
Inspect the microswitches: Verify that the microswitches are functioning properly and are not damaged or misaligned.If you have followed these steps and the system is not operating as expected, it is recommended to consult with an experienced electrician or fire suppression technician for further troubleshooting. Flag for review