Have 3 rooftop units with built in duct smokes, wired to shut down the unit if smoke is detected. I need to monitor these 3 devices via the FACP. I brought the buildings initiating loop to each unit. I was told that this is incorrect by the company who provided the FACP, they claim that I need to pull another wire to the units, and if they go off a simple trouble would be all that will occur not an alarm. If I recall, this is not what I have seen before. Is this usually the case? Thanks a lot.
Duct smokes
- Thread starter JohnME
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mdshunk
Senior Member
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- Right here.
Sounds like the model they are using has a trouble contact. Makes good sense to me.
quogueelectric
Senior Member
- Location
- new york
There usually would be an alarm initianating loop with depending on the cfm of the unit if both supply and return ducts are protected or just One or the other.JohnME said:
There is usually a remote indicating led mounted in the cieling tile belowthe unit being protected.
Then there is usually a fan shutdown relay Usually wired in 14-2 back to the facp to break the control circuit Either at a designated fire shutdown point in the rooftop unit or break the control ckt right after the control fuse.
Sometimes motorized smoke dampers are also tied into the fresh air intake supply or return ducts. It is very important that the end switches are correctly wired into the start circuits so that the fan does not come on with the damper closed.
Thanks guys. These are already factory wired trane units, I just need to hit the contacts with my 14/2, so that when the unit does sense smoke, the panel goes into trouble. The factory wired end of things shuts the unit down. I am simply monitoring the device.
Thats my understanding of it anyway.
Thats my understanding of it anyway.
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