Shutdown Relays on NAC Circuits

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PMcCarty

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Does any Know?

NAC is a "Notification Appliance Circuit." Notification Appliances are suppose to be connect to these circuits. I found a system that has many Exhaust Fan Shutdown relays wired to the NAC circuit. Is this approved by code?

Reading the definitions, it is not. Only notification Appliances are to be connected. There are other wiring methods for connecting shutdown relays.

I could not find anything else that specifically stated that these relays could not be on this circuit.

Thanks

Phil
 
PMcCarty said:
There are other wiring methods for connecting shutdown relays.
Click to expand...

Sure, for an analog system you normally use the auxillary contacts on the panel.

For an addressable system you can use additional control modules in the IDC loop.
 
I'm wondering how this issue was resolved....

I'm wondering how this issue was resolved....

Just curious.....what make & model of fire alarm panel are you dealing with? The relays you referred to have not been listed for use with any fire alarm panel I've worked on, but that is not the same as saying that they're not listed.....
 
Remote Polarized Relay

Remote Polarized Relay

PMcCarty said:
Does any Know?

NAC is a "Notification Appliance Circuit." Notification Appliances are suppose to be connect to these circuits. I found a system that has many Exhaust Fan Shutdown relays wired to the NAC circuit. Is this approved by code?

Reading the definitions, it is not. Only notification Appliances are to be connected. There are other wiring methods for connecting shutdown relays.

I could not find anything else that specifically stated that these relays could not be on this circuit.

Thanks

Phil
Click to expand...


Siemens markets a relay just for this purpose, the RPR-1. It draws 0.05 amps at 15-30 VDC. When wired to a polarity reversal circuit, the supply wire is supervised. It can switch loads of 3 amp at 28 VDC or 5 amp at 120 VAC.

"This unit allows the fire alarm system control unit to provide emergency control or activation of other systems in the building such as air handling systems, door control devices, smoke control systems, or other functions required by the local code and/or local authority."

Sorry I can't provide a link to the installation manual, it's in a password protected part of the Siemens web site.
 
The relays on your link are not listed for FA use. Normally it is not acceptable to use a NAC for this purpose, need more details on the panel and configuration. But if the NAC is silenceable, then the fans could start back up when the audibles are silenced. I've never seen this as an acceptable configuration.
 
While I've not seen this done either,

While I've not seen this done either,

Mccleldr said:
The relays on your link are not listed for FA use. Normally it is not acceptable to use a NAC for this purpose, need more details on the panel and configuration. But if the NAC is silenceable, then the fans could start back up when the audibles are silenced. I've never seen this as an acceptable configuration.
Click to expand...

I've read about it being done using relays listed for use with a particular model of fire alarm panel, and used on a non-silenceable NAC (a strobe circuit, as an example, so that the relay contacts restore on a system reset, not on an alarm silence command). Likely harks back to the day when panels were more.....primitive....
 
There are fire alarm profesionals that design these systems. Electricians for the most part do not fall into the design category I dont understand why they try to.
 
quogueelectric said:
There are fire alarm profesionals that design these systems. Electricians for the most part do not fall into the design category I dont understand why they try to.
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Me, too.

My insurance would never allow me to assume that liability.

I just installed the stuff . . .

Best Wishes Everyone
 
Thank you all for your replies to my question. You are correct that these are not authorized for F/A systems and especially installed on the NAC. We are in the process of changing them out and rewiring.
 
Some notification systems like hor/strobes have a reverse polarity feature on them where after a couple of minutes the horns stop while the strobes keep flashing until reset. There is a blocking diode in the horn circuit so it cuts out the horns when polarity reverses. You have to be very careful when WINGING IT.
 
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