N.E.C. question regarding Fire alarm power feed

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SOG38

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For many years, when asked by our installers, how many FA panels can be powered by one breaker I have asked for one breaker for one FA panel. My reasoning was for maximum reliability one breaker per FA panel. No other reason.
Now I have been questioned as to ?is there a N.E.C. requirement?. I have dug around and really found nothing specific. Any help would be greatly appreciated.
 
The relevant NEC requirements are going to deal with the amount of load you can put on a single circuit. How much load does one of your panels draw?
 
N.E.C.Requirements

N.E.C.Requirements

I'm not looking to help size a breaker for the applied load.
I have single panels that draw from .5 A to 12 A.
I'm looking foe any requirements that do or don't limit the number of panels on a breaker.
Thanks.
 
Nothing limits the number of panels. For a 20 amp circuit, you need to limit the load to 16 amps. Reference is NEC 210.20(A).
 
would say only one FA panel per individual branch circuit required by 760.41(B) and 760.121(B).

Chris
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would you also apply this to fa nac panels?
 
N.E.C.Requirements

N.E.C.Requirements

As I read the scope of 760 doesn't it refer to the circuits controlled and powered by the FA. not input to the panel.
Thanks.:confused:
 
SOG38 said:
As I read the scope of 760 doesn't it refer to the circuits controlled and powered by the FA. not input to the panel.
Thanks.:confused:
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760.41(B) is dealing with the branch circuit supplying Non-power limited fire alarm circuits.

760.121(B) is dealing with the branch circuit supplying power limited fire alarm circuits.

Both of these sections require an individual branch circuit to supply power to the source of the fire alarm circuits.

An individual branch circuit is defined as "A branch circuit that supplies only one utilization equipment."

Chris
 
raider1 said:
I would say only one FA panel per individual branch circuit required by 760.41(B) and 760.121(B).

Chris
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Since NFPA 70-2005 doesn't have a 760.121(B), I assume you are refering to the 2008 edition?

That said, I don't see any limitation on the number of fire alarm panels you can supply from a single circuit. In fact, assuming you don't, as previously mentioned, exceed the ampacity for the circuit, we will power the panel and a couple of NAC boosters from the same circuit. I see also that both .41 and .121 use "circuits", plural, in their headings.
 
gadfly56 said:
Since NFPA 70-2005 doesn't have a 760.121(B), I assume you are refering to the 2008 edition?

That said, I don't see any limitation on the number of fire alarm panels you can supply from a single circuit. In fact, assuming you don't, as previously mentioned, exceed the ampacity for the circuit, we will power the panel and a couple of NAC boosters from the same circuit. I see also that both .41 and .121 use "circuits", plural, in their headings.
Click to expand...

Yes, these code sections are from the 2008 NEC.

The problem is that an individual branch circuit is a defined term in Article 100 and is defined as;

A branch circuit that supplies only one utilization equipment.
Click to expand...

I read that to mean that the branch circuit can only supply one FACP.

Chris
 
raider1 said:
Yes, these code sections are from the 2008 NEC.

The problem is that an individual branch circuit is a defined term in Article 100 and is defined as;



I read that to mean that the branch circuit can only supply one FACP.

Chris
Click to expand...

Hmmm, looking at the definition, I think your point is at least plausible, if not certain, although this requirement is not in the '05 edition (current in NJ). This was somone's careless attempt to ensure that the fire alarm panel would get a "dedicated" brach circuit, said individual argueably never having designed anything beyond a simple one-panel system.
 
charlie b said:
Nothing limits the number of panels. For a 20 amp circuit, you need to limit the load to 16 amps. Reference is NEC 210.20(A).
Click to expand...

This little, but important fact get over looked by a lot of AHJ's and EE's.

Man do they get defensive "I didn't miss a critical calculation...Oh crap I did."
 
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