HVAC shutdown with F/A system and Chlorine Detection system

[Futboldt9]

Hi guys,

We're doing an install which involves the small standalone building to be air neutral (shutdown of BCU's, HP's, HRV, ceiling fans, etc...) in the case of Chlorine detection and/or Fire alarm.
There is a Chlorine Detection panel as well as an addressable Fire Alarm panel (Notifier). The sequence of events shows each panel having the capability of shutting down all HVAC equipment to make building air neutral however I've been beating my head on how we wire this as I've never done a system with both F/A and Chlorine Detection. This is a no brainer for me if it was just F/A and we were shutting HVAC down in only a fire alarm state as we would use the relay modules. But what is the best way to go about this with the F/A system and Chlorine system as well? Chlorine detection system has four internal SPDT dry contact relays
rated 5A @ 240V

Would love to hear your input.

Thanks!

 

[hbiss]

This is a no brainer for me if it was just F/A and we were shutting HVAC down in only a fire alarm state as we would use the relay modules. But what is the best way to go about this with the F/A system and Chlorine system as well? Chlorine detection system has four internal SPDT dry contact relays

Seems to me that you would wire it the same as the F/A shutdown.

-Hal

 

[ron]

If the chlorine panel would only shut the equipment down, then you would put your shutdown contact in series with the start circuit along with the fire alarm relay that you typically would, so either will shutdown.
If the chlorine panel can also start a piece of equipment in a life safety situation that is off due to other control sequences, then you would have to be able to bypass the the shutdown contacts (in parallel)