Fire smoke dampers emergency or stand by

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hhsting

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I have high rise and hospital building which has Fire Smoke dampers. Should the Fire Smoke Dampers be installed in emergency circuit or standby circuit? Which NEC 2017 code section?
 
In general, the NEC does not have requirements like that. The NEC tells you how to wire it after some other code has told you what system it needs to be supplied by. This would be a building or fire code issue.
 
don_resqcapt19 said:
In general, the NEC does not have requirements like that. The NEC tells you how to wire it after some other code has told you what system it needs to be supplied by. This would be a building or fire code issue.
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Fire Smoke Dampers (FSD) are on equipment branch. I thought 517 would say something about them being on emergency or equipment branch.

Where exactly in building or fire code?
 
hhsting said:
Fire Smoke Dampers (FSD) are on equipment branch. I thought 517 would say something about them being on emergency or equipment branch.

Where exactly in building or fire code?
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No idea...I don't have copies of those other codes....not my job
 
They would need to be "fail safe" and the codes that apply would lead you to your answer.

Roger
 
hhsting said:
Fail safe?


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Powered open, spring return. Caution is indicated here, because you don't want power failing to the dampers and having them shut before the air handlers shut down, or you may turn some of your rectangular duct into round duct.
 
gadfly56 said:
Powered open, spring return. Caution is indicated here, because you don't want power failing to the dampers and having them shut before the air handlers shut down, or you may turn some of your rectangular duct into round duct.
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Please see attached. Schematic Wiring Diagram shows rectangle with CM which has arrow pointing to it that says close damper when fan not running. Their is also rectangle with MM that says sense fan status to initiate closure of all smoke dampers. Would that all be fail safe?

a88add6db6bc410c45459801c69a9c3e.jpg
 
This is above your expertise and should be sent up to someone in your firm that has some knowledge in HVAC.

Roger
 
roger said:
This is above your expertise and should be sent up to someone in your firm that has some knowledge in HVAC.

Roger
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He wont check electrical plans.

Fire smoke damper is in duct and the damper actuator motor power is on equipment branch. I really don’t care why thats their or if it is needed thats HVAC but should it be on equipment branch or life safety branch that part is I am not sure about. Electrical plans show homerun to panelboard circuit thats on equipment branch and shows that panelboard riser on equipment branch
 
hhsting said:
Please see attached. Schematic Wiring Diagram shows rectangle with CM which has arrow pointing to it that says close damper when fan not running. Their is also rectangle with MM that says sense fan status to initiate closure of all smoke dampers. Would that all be fail safe?

a88add6db6bc410c45459801c69a9c3e.jpg
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Nope, not fail safe, unless there is hidden information on the 120VAC actuator. The key is the MM for sensing the fan state. That can be done a couple of ways. You can pick up a contact output from the AHU controller, or someone puts in a EOLR-1 or equal that changes state when the fan motor is energized and de-energized. The MM picks that up, and its output becomes part of an AND function which tells the fire alarm control unit (FACU) "If fan is off, AND duct detector is active, trigger CM to close smoke damper". For this reason, all elements should be on emergency power, whether 701 or 702. LaGuardia has it all on a 701 system. There is a missing piece here, which should be a CM that tells the AHU to shut down. That could also be auxiliary contacts from the duct detector, if it happens to be within 3 feet of the AHU fan controller.
 
gadfly56 said:
Nope, not fail safe, unless there is hidden information on the 120VAC actuator. The key is the MM for sensing the fan state. That can be done a couple of ways. You can pick up a contact output from the AHU controller, or someone puts in a EOLR-1 or equal that changes state when the fan motor is energized and de-energized. The MM picks that up, and its output becomes part of an AND function which tells the fire alarm control unit (FACU) "If fan is off, AND duct detector is active, trigger CM to close smoke damper". For this reason, all elements should be on emergency power, whether 701 or 702. LaGuardia has it all on a 701 system. There is a missing piece here, which should be a CM that tells the AHU to shut down. That could also be auxiliary contacts from the duct detector, if it happens to be within 3 feet of the AHU fan controller.
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Was able to gather more info from electrical engineer:

The Fire Smoke Damper is installed where duct penetrate the wall which is fire rated.
So in order to maintain the Fire or Smoke rating the fire smoke damper is installed. It is Not part of smoke removal control system.

You are correct the fire smoke damper is open when power on and no power closes. So default without power it shuts.

The air handler unit is also on equipment branch.

When their is a smoke the smoke detector signal fire alarm control panel which then signal the damper shut. Even when generator kick in equipment branch is energized if their is smoke the dampers would be shut by the fire alarm control panel. This is not what you indicate above? One thing is this could led to possibility where air handler comes on and dampers are shut off and then duct shape as you indicate post #8 would be problem no?
Also would above be fail safe?

Anyways So what do you think in terms of being fire smoke damper in equipment branch or emergency branch?
 
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hhsting said:
Blue text?? But mine is on equipment branch

6866da75e3af8444bb147b2bff945245.jpg



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Blue text is just someones opinion and not a code rule and no more valid than your opinion or my opinion.

Even if the blue text is 100% correct it only says permitted to be on the life safety branch, does not say required to be on the life safety branch, so it still does not answer your question.
 
hhsting said:
Was able to gather more info from electrical engineer:

The Fire Smoke Damper is installed where duct penetrate the wall which is fire rated.
So in order to maintain the Fire or Smoke rating the fire smoke damper is installed. It is Not part of smoke removal control system.

You are correct the fire smoke damper is open when power on and no power closes. So default without power it shuts.

The air handler unit is also on equipment branch.

When their is a smoke the smoke detector signal fire alarm control panel which then signal the damper shut. Even when generator kick in equipment branch is energized if their is smoke the dampers would be shut by the fire alarm control panel. This is not what you indicate above? One thing is this could led to possibility where air handler comes on and dampers are shut off and then duct shape as you indicate post #8 would be problem no?
Also would above be fail safe?

Anyways So what do you think in terms of being fire smoke damper in equipment branch or emergency branch?
Click to expand...

Anyone know or can assist please?


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Just ask the engineer what you should do.

Roger
 
hhsting said:
Anyone know or can assist please?


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In my opinion, emergency branch, for reasons I've stated above.

Otherwise, send an RFI to the design team and have them tell you.
 
gadfly56 said:
In my opinion, emergency branch, for reasons I've stated above.

Otherwise, send an RFI to the design team and have them tell you.
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So I am not sure if you caught the part that the damper shuts when power failure and damper stays open when their is power.

Would fail close damper such as above require emergency power?
 
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