US Fire Alarm System Regulations 1

[Graeme38]

I would be interested to know if the US fire alarm system regulations require a minimum noise levels.

In the UK the requirement is 65dB minimum in any normally occupied room or 5dB above ambient noise levels. For sleeping accommodation it is 75dB minimum.

We are also required to provide a minimum of two sounder circuits in the event of a circuit failure of one.

I recently carried out an installation in South America, and I found the system used (Siemens) supplied from the US to be fairly limited in this department. The system could only drive a limited number of sounders

 

[beghtesady]

the answear to your question can be found in the NFPA 72.

 

[ElecDar]

Graeme38,
You have to review NFPA 72 as there are many recommendations and exceptions, which should be reviewed before designing the system.

However, for your information, the Average Ambient Sound Level (noise level) According to Location is described in Table A-4-3.2 of NFPA 72.

I assume that you are interested in the recommended minimum sound pressure level for the various areas, not the noise level,If my assumption is correct the following may help you:

Sleeping area: at least 15 dBA above the average ambient sound level or 5 dBA above the maximum sound level having a duration of at least 60 seconds or a sound level of at least 70 dBA, whichever is greater, measured at the pillow level in the occupiable area.

Private Mode: not less than 45 dBA at 3 m from the audible appliance and at least 10 dBA above the average ambient sound level or 5 dBA above the maximum sound level having a duration of at least 60 seconds, whichever is greater, measured 1.5 m above the floor in the occupiable area.

Public Mode: not less than 75 dBA at 3 m from the audible appliance and at least 15 dBA above the average ambient sound level or 5 dBA above the maximum sound level having a duration of at least 60 seconds, whichever is greater, measured 1.5 m above the floor in the occupiable area.

 

[Graeme38]

ElecDar,

Many thanks for your information.

Regards,

Graeme

 

[cuky2000]

EleDar,

In apprciation for the good answer, I vote for an star for this post.

 

[ElecDar]

cuky2000,

Thank you for the appreciation and the STAR.