User's Manual

Design
P/N 81-CO2MAN-001 3-75 September 2013
3-14.3 Automatic Detection
The type of detector required for a particular application is dependent upon the type of
combustible products being protected. When designing a detection system, the system
designer must consider the following factors:
• Type and quantity of fuel
• Possible ignition sources
• Ranges of ambient conditions
• Value of protected property
The detection shall be by any listed or approved method or device that is capable of detecting
and indicating heat, flame, smoke, combustible vapors or an abnormal condition in the hazard
such as a process trouble that is likely to produce fire. When designing a suitable detection
system, it is necessary to survey the premises and gather intricate details such as ceiling types,
ceiling obstructions, (e.g. beams, joists, light fixtures, location of air diffusers and return
grills), ambient conditions (e.g., temperature and humidity) and elevation with respect to sea
level. When using smoke detectors for system actuation, it is recommended to space the
detectors at a maximum of half the listed spacing. Refer to NFPA 72 and manufacturer's
recommendations for coverage area and detector spacing.
3-14.4 Manual Controls
Manual pull stations for carbon dioxide release should be located at all exit/entrance doors and
shall be easily accessible at all times. For areas protected with total flooding applications, the
manual pull stations should be installed outside the protected area. At least one manual control
shall be located no more than 4 ft. (1.2 m) above the floor.
Abort switches shall not be used in CO
2
suppression systems.
3-14.5 Notification
Pre-discharge alarm shall be provided to give positive warning of a discharge where hazards
to personnel could exist. Such alarms shall function to warn personnel against entry into
hazardous areas as long as such hazards exist or until such hazards are properly recognized.
Audible pre-discharge alarms shall be at least 15 dB above ambient noise level or 5 dB above
maximum sound level, whichever is greater, measured 5 ft. (1.5 m) above the floor of the
occupiable area. Such alarms shall have a maximum sound level of 120 dB at the minimum
hearing distance and a minimum sound level of 90 dB at 10' (3 m).
Visual or other methods of indication are also recommended.
3-14.6 Supervision of Controls
Interconnections between the components that are necessary for control of the system and life
safety, such as lockout valves and manual bypasses that may be left in the open position shall
be supervised. Such supervisory alarms shall be distinctive from alarms indicating system
operation or hazardous conditions.
3-14.7 Main and Reserve System Actuation
For systems with a connected reserve agent supply, the Main-to-Reserve Transfer Switch, Part
No. 84-802398-000, is used to select the supply to be discharged. Reference Paragraph 4-4.5
for wiring information.