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Fire Alarm Notification Appliance Circuit Calculator Excel Spreadsheet

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Fire Alarm Notification Appliance Circuit Calculator Excel Spreadsheet

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Download: Fire Alarm Notification Appliance Circuit Calculator Excel Spreadsheet

A fire alarm notification appliance is an active fire protection component of a fire alarm system. A notification appliance may use audible, visible, or other stimuli to alert the occupants of a fire or other emergency condition requiring action. Audible appliances have been in use longer than any other method of notification. Initially, all appliances were either electromechanical horns or electric bells, which would later be replaced by electronic sounders. Most of today's appliances produce sound pressure levels between 45 and 120 decibels at ten feet.

The primary function of the notification appliance is to alert persons at risk. Several methods are used and documented in industry specifications published by UL.

Alerting methods include:

Sound (audible signals)
~3 kHz / ~3100 Hz tone (high frequency). Used in many current notification devices.
520 Hz (low frequency). Used in newer notification devices.
45 dB to 120 dB A weighted for human hearing (higher decibels, in the 100 to 120 dB range, were common with older electromechanical horns)
Light (visible signals)
15 cd to 1000 cd candela output
1 to 2 flashes per second


Distribution and dB Calculations

- This sheet can be used to calculate wire distances for any 24Vdc (or FWR) Notification Appliance Circuit (NAC) as well as audio circuits if you know the device loads and panel specs.

- Distances will be worst case (end loaded). Longer distances may be achieved if other calculations are done for evenly distributed devices on the NAC.

- If using Edwards signaling devices, you can use the Load NAC( ) sheets to calculate circuit loads, which can then be entered below for NAC( ) operating currents.

- The Load SpkrStrb sheet is for speaker loading (used with audio panels). The strobe currents from that sheet will have to be assigned to one or more of the 24V NACs

Load for Horns and Horn Strobes

Notes :

1) Enter quantities below per circuit in yellow boxes. Totals will appear to the right.

2) Be sure total does not exceed panel's NAC rating.

3) For FWR power supplies, such as E-FS(C)(A) panels, use the FWR currents.

4) For dc power supplies, such as the EBPS6(10)A, use the dc currents.

5) Currents are worst case (U.L. nameplate) values.

6) This page does not list all the available fire alarm signals. Refer to catalog for additional choices.

INdoor Speakers and Speakers Strobes


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