Selective coordination

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binwork91

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Location
new york
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electrical engineer
I have a job.
There is a panel, it include the 20A breaker feeds Fire smoke damper.
The upstream is 100A breaker.
This panel does not connect to generator.

Question: does 20A breaker required coordinate with upstream 100A breaker?
 

GoldDigger

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Location
Placerville, CA, USA
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Retired PV System Designer
Tell us more about what type of building and its use, please. What category of circuits does the generator support, and with how many transfer switches?
 

charlie b

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Lockport, IL
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Retired Electrical Engineer
Selective coordination is only required in certain installations, and this is not one of them. That is because the circuit does not connect with the generator. So my answer is no.
 

binwork91

Member
Location
new york
Occupation
electrical engineer
Tell us more about what type of building and its use, please. What category of circuits does the generator support, and with how many transfer switches?
It is high rise hotel building. it have about 10 ATS.
i don't think generator and ATS is important to my question.
I think it is a NEC code question.
 

binwork91

Member
Location
new york
Occupation
electrical engineer
Selective coordination is only required in certain installations, and this is not one of them. That is because the circuit does not connect with the generator. So my answer is no.
I kinda agree with you. The only problem i concern is Fire Smoke Damper is relate to Fire Alarm System. So i don't know if it need to be selective coordinate.
 

charlie b

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Lockport, IL
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Retired Electrical Engineer
It is related to the fire alarm system. But it is not an article 700 "emergency load," nor is it an article 701 "legally required standby load." That is because if it loses power, it fails to its safe position of closed. Nothing in the Fire Alarm article 760 calls for selective coordination.
 

jim dungar

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Location
Wisconsin
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PE (Retired) - Power Systems
I agree with Charlie.
But if you want to continue to evaluate the coordination, you need to know the available fault current at the fire smoke damper. This will tell you the point at which you can ignore any overlap of protective devices.
 

binwork91

Member
Location
new york
Occupation
electrical engineer
It is related to the fire alarm system. But it is not an article 700 "emergency load," nor is it an article 701 "legally required standby load." That is because if it loses power, it fails to its safe position of closed. Nothing in the Fire Alarm article 760 calls for selective coordination.
Thank you
 
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