Notification appliance circuit definition

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nhfire77

Senior Member
Location
NH
So I know what it is, but what about this:

120vac motor bell switched by a DPST waterflow switch from a sprinkler system, it's not a supervised circuit. The bell is to notify the arriving FD water is flowing, not just a general alarm. There is a complete fire alarm system. The other side of the switch is monitored by the FACP. Very normal situation.

Now take that same bell and make it a 24vdc bell. The bell receives it's power from the FACP aux power supply through an addressable relay module that is mapped(programmed) to activate upon any waterflow condition. The wiring to the bell is not supervised. Is that a NAC and should it be supervised?

If the 120 VAC circuit isn't then just because the power is derived from the FACP does that trigger the supervision requirement?

What about a specfically coloered strobe located outside in place of the 24v bell?


I'm believe it does, but since the 120v doesn't, it's confusing to some. Maybe I'm wrong, what do you think?

Also, most plans I have show these devices off a relay, no one seems to care, but I may have to defend my position, if I challenge this. I'm not looking for a fight, whatever is right, is right.
 

vanvan

Member
Hmmmmm.... i would think you would monitor it in both situations. At 120v with a PAM-1 relay and monitoring module and at 24v with EOL.
 

nhfire77

Senior Member
Location
NH
Hmmmmm.... i would think you would monitor it in both situations. At 120v with a PAM-1 relay and monitoring module and at 24v with EOL.
I've been doing fire alarms for 15 years, I've never seen a bell fed with 120v supervised with a relay, mainly because the 120v is supervised by the panel, because you tap the panel feed for the bell. Again, in my experience.

Also, in my experience, there not supervising the 24 all the time either. Doesn't make it right though.
 

vanvan

Member
oh got it... for some reason i was visualizing a 120v bell being fed from diff source triggered by 24v from FACP on water flow. I def appreciate all your experience in fire alarms. I have been trying to read as much of it as i could. Have just completed my first system from start to finish (EST in small 9 story MOB with 5 levels of parking) and should have my final this week. So much going on and so many rules it has kept me up at night this past year! Thanks for all your posts and being active on this site!
 

del91574

Member
Location
ct
Depends on the panel and module used, but we commonly do similar and supervise the power in the case of a LV bell. We've done similar using HV tandem smokes in residence units, usually healthcare, with a module and supervise the 120V on the side of the control module.
 

gadfly56

Senior Member
Location
New Jersey
Occupation
Professional Engineer, Fire & Life Safety
Recycled Reply

Recycled Reply

So I know what it is, but what about this:

120vac motor bell switched by a DPST waterflow switch from a sprinkler system, it's not a supervised circuit. The bell is to notify the arriving FD water is flowing, not just a general alarm. There is a complete fire alarm system. The other side of the switch is monitored by the FACP. Very normal situation.

Now take that same bell and make it a 24vdc bell. The bell receives it's power from the FACP aux power supply through an addressable relay module that is mapped(programmed) to activate upon any waterflow condition. The wiring to the bell is not supervised. Is that a NAC and should it be supervised?

If the 120 VAC circuit isn't then just because the power is derived from the FACP does that trigger the supervision requirement?

What about a specfically coloered strobe located outside in place of the 24v bell?


I'm believe it does, but since the 120v doesn't, it's confusing to some. Maybe I'm wrong, what do you think?

Also, most plans I have show these devices off a relay, no one seems to care, but I may have to defend my position, if I challenge this. I'm not looking for a fight, whatever is right, is right.
I dug this up from one of my old posts:

"NFPA 72 requires only that a waterflow alarm device be provided. The kicker comes from NFPA 13 which requires an alarm device be provided and that it continue to sound until the waterflow stops (3-10.1) If someone silences the panel and the NAC the waterflow alarm device is on isn't or can't be set as non-silenceable, you would violate the requirements of NFPA 13. Easier to grab a handy 120 VAC line and wire it up.

Oddly enough, on a quick look, it doesn't appear that this device is required to be supervised in either NFPA 13 or 72. In fact, if the waterflow alarm device is electrically operated and is NOT part of a required protective signaling system, it shall not be supervised per 3-10.5.1 and shall be installed per NFPA 70 article 760. It is possible that "supervised" in this context means sending a signal to a "contstantly attended location" but I wouldn't swear to that. "

So 120 AC or 24 DC the device doesn't have to be supervised. I try like heck not to put things in that way. How many buildings might catch fire during a blackout? I don't want to be deposed for even one. Ever.
 

nhfire77

Senior Member
Location
NH
I dug this up from one of my old posts:

"NFPA 72 requires only that a waterflow alarm device be provided. The kicker comes from NFPA 13 which requires an alarm device be provided and that it continue to sound until the waterflow stops (3-10.1) If someone silences the panel and the NAC the waterflow alarm device is on isn't or can't be set as non-silenceable, you would violate the requirements of NFPA 13. Easier to grab a handy 120 VAC line and wire it up.
Since the panel can just assign the waterflow output as non-silenceable I would rather have control of the bell from the panel. I did not realize the issue with the silencing of the bell, that makes it interesting. We wire for 24V, so normally the WF mapping is latching, silenceable . But according to 13 it would have to be non-latching and non-silenceable. Luckily most FD's around here require audible silence so they can leave the strobes going and leave the panel silenced in alarm. That gets issues fixed faster, you know: OMG your leaving that on!?!?!?!?!! Call the alarm company!!! Emergency service, please.

Oddly enough, on a quick look, it doesn't appear that this device is required to be supervised in either NFPA 13 or 72. In fact, if the waterflow alarm device is electrically operated and is NOT part of a required protective signaling system, it shall not be supervised per 3-10.5.1 and shall be installed per NFPA 70 article 760. It is possible that "supervised" in this context means sending a signal to a "contstantly attended location" but I wouldn't swear to that. "

So 120 AC or 24 DC the device doesn't have to be supervised. I try like heck not to put things in that way. How many buildings might catch fire during a blackout? I don't want to be deposed for even one. Ever.
I am referring to conductor supervision, and yea that is why I'd rather add the 24v bell and have it battery backed up.
 

MisterCMK

Member
Location
Twin Cities, MN
I think the fire marshal would have the final say on that one. I've seen it done any number of ways from having a CR control the 120V power for the outside horn to having a separate NAC circuit or CC1 for the outside horn or just having a CR trip a 24v horn. It usually depends on what the AHJ wants and what the circumstances dictate.
 

Stallzer

Member
Location
MN
So we're all on the same page, you are referring to the (Exterior) Horn / Strobe above the Siamese connection coming into the Building ?
 

nhfire77

Senior Member
Location
NH
I believe the answer is yes.
Yes, but its not a general alarm. My original question was specifically about the mechanical bell.

The local FD requires a separate strobe just for water flow, and the mechanical bell. There are two strobes. Red is general alarm. Green is water flow.
 

Stallzer

Member
Location
MN
So if I'm reading this correctly:

The outside Bell / Strobe is strictly for the Fire Department to be able to locate the Siamese Connection on the Building, hence the reason it has to be mounted above this. This Circuit should be independent from the FACP as required by code so in case the FACP has any kind of issue you still can Turn on the outside Appliance since it's utilizing a Mechanical switch. I have never seen anyone think of Running 24VDC off the FA Aux Power supply to the 2nd set of switches on a flow Switch.
 

nhfire77

Senior Member
Location
NH
So if I'm reading this correctly:

The outside Bell / Strobe is strictly for the Fire Department to be able to locate the Siamese Connection on the Building, hence the reason it has to be mounted above this. This Circuit should be independent from the FACP as required by code so in case the FACP has any kind of issue you still can Turn on the outside Appliance since it's utilizing a Mechanical switch. I have never seen anyone think of Running 24VDC off the FA Aux Power supply to the 2nd set of switches on a flow Switch.
No, the 120v bell would be switched off the flow switch, the green strobe is on a dedicated 24v NAC The red strobe is on any NAC.

Why would you say a the bell and strobe has to be separate from the FACP? It's a system device.

In the completely 24v system, the bell and green strobe is on a dedicated NAC, the red strobe is on any NAC.
 

Stallzer

Member
Location
MN
I believe we are talking about the same thing. The Flow switch has 2 sets of contacts. 1 Set of contacts should be a dedicated 120vac circuit to the outside Siamese connection Horn / Strobe and the 2nd set of contacts should be for FA system Monitoring. The reason for this is simply a back-up plan in case the FACP goes down there is an independent means of Notification for the Fire Department to locate the Siamese hook up.
 
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