Fire Zone Classification 1

[MechEngCCGT]

Dear All,

I have the following question:
In a combined cycle power plant (CCGT) in the control rooms (DCS) smoke detection system exist in:
- Under the raised floor
- In the working area
- Above the false ceiling
Can these locations be classed as one fire zone or has the floor and the ceiling be fire resistant acc. to NFPA?

Which is the most applicable NFPA code and paragraph on this to have a look?
Thank you

 

[cdafd]

Guess why are you asking if they are fire zones?

 

[stookeyfpe]

Are you asking about zoning for the purpose of fire alarm annunciation or for the purpose of creating separate fire areas?

 

[MechEngCCGT]

stookeyfpe I am asking because I want to know the following:
1. First off all can all these locations be classed as one fire zone?
2. Should all the floor and the ceiling be fire resistant and if yes for how long and acc to which standard?

I apologise in advance this is not my area of expertise so some questions may have logical gaps to you guys. Any help appreciated.
Regards

 

[stookeyfpe]

Redbayron:

1. Yes, but it depends on the area of the building and number of stories.
2. I can't answer this. I don't know what building code is in effect where you are located.

 

[cdafd]

is this kind of what you are looking for???::::


10.18.5* Annunciation Zoning.


A.10.18.5 Fire alarm system annunciation should, as a minimum, be sufficiently specific to identify a fire alarm signal in accordance with the following:


(1)
If a floor exceeds 22,500 ft2 (2090 m2) in area, the floor should be subdivided into detection zones of 22,500 ft2 (2090 m2) or less, consistent with the existing smoke and fire barriers on the floor.


(2)
If a floor exceeds 22,500 ft2 (2090 m2) in area and is undivided by smoke or fire barriers, detection zoning should be determined on a case-by-case basis in consultation with the authority having jurisdiction.


(3)
Water floor switches on sprinkler systems that serve multiple floors, areas exceeding 22,500 ft2 (2090 m2), or areas inconsistent with the established detection system zoning should be annunciated individually.


(4)
In-duct smoke detectors on air-handling systems that serve multiple floors, areas exceeding 22,500 ft2 (2090 m2), or areas inconsistent with the established detection system zoning should be annunciated individually.


(5)
If a floor area exceeds 22,500 ft2 (2090 m2), additional zoning should be provided. The length of any zone should not exceed 300 ft (91 m) in any direction. If the building is provided with automatic sprinklers throughout, the area of the alarm zone should be permitted to coincide with the allowable area of the sprinkler zone.



The provisions of 10.18.5 specify the minimum zoning required by NFPA 72. Fire alarm system notification zones, which are addressed by these provisions, should correlate with building smoke and fire zones. This correlation is especially important if an in-building fire emergency voice/ alarm communications system is used to selectively or partially evacuate occupants or to relocate occupants to areas of refuge during a fire. Definitions for the terms zone evacuation signaling zone, and notification zone can be found in 3.3.320. In addition, refer to the requirements in 23.8.6.3 for notification zones and the requirements in 24.4.2.9 for evacuation signaling zones.
Additional zoning requirements may exist in the governing building codes; NFPA 101; NFPA 5000® Building Construction and Safety Code®; and local ordinances. These higher level documents often require each floor of a building to be zoned separately for smoke detectors, waterflow switches, manual fire alarm boxes, and other initiating devices. The zoning recommendations found in A.10.18.5 parallel the annunciation zoning requirements found in NFPA 101 and the model building codes. The Code, as a minimum installation standard, does not require that an addressable system control unit be used. Conventional (zone) alarm control units are often adequate enough to meet the annunciation zoning requirements.




10.18.5.1 For the purpose of alarm annunciation, each floor of the building shall be considered as a separate zone.


10.18.5.2 For the purposes of alarm annunciation, if a floor of the building is subdivided into multiple zones by fire or smoke barriers and the fire plan for the protected premises allows relocation of occupants from the zone of origin to another zone on the same floor, each zone on the floor shall be annunciated separately.


10.18.5.3 Where the system serves more than one building, each building shall be annunciated separately.

 

[MechEngCCGT]

Thank you guys,
I ll have a look in NFPA 72.
Regards