Janus FM-200 Sv Series - 3 System Design; 3.1 Hazard Analysis

Page: 37
FM-200® OPERATION, DESIGN, & SERVICE MANUAL
Revision F
Document # DOC102
Issued: February 1, 2009
Revised: 11-Nov-2011
40YE
Section 3 System Design
3 SYSTEM DESIGN
is section lists the methods and guidelines necessary to properly design an engineered Janus Fire Systems®
FM-200® Fire Extinguishing System.
Note: Janus Fire System® Fire Extinguishing Systems are designed, manufactured, installed and UL listed
and FM approved to deliver a designated quantity of FM-200® in a "not to exceed" 10 second discharge
time. e "Duration of Protection (Hold Time)" as referenced in NFPA 2001, 2012 edition is a function
of the hazard enclosure's (room) integrity and not a function (or capability) of the re suppression systems
referenced in this publication.
3.1 Hazard Analysis
e rst step in designing an engineered FM-200® total ooding system is to identify the unique
requirements of the area to be protected.
3.1.1 Fuel Source
e design specications for the FM-200® system are dependent on the hazard type, so it is rst necessary
to identify the type of hazard to be protected.
Hazard type is classied according to the combustible materials found in an area and may be considered
Class A (wood, paper, cloth, rubber, and many plastics), Class B (ammable liquids and ammable gases),
Class C (energized electrical equipment), or any combination of the three.
NFPA 2001 (2012 edition) requires the minimum design concentration for a Class A surface re to be equal
to 6.7% (7% for FM Approved systems), the minimum extinguishing concentration of heptane.
e minimum design concentration for a Class B re depends on the extinguishing concentration for the
specic fuel type found in the hazard plus a 30% safety factor. e minimum design concentrations for
particular fuels based upon their cup burner extinguishing concentration are listed in Tables 3.1.1a and
3.1.1b in Appendix B.
e minimum design concentration for a Class C re shall be 7.0% (7.8% for FM Approved systems), which
is equal to the extinguishing concentration of Class A fuels times a safety factor of 1.35, in accordance with
NFPA 2001 (2012 edition).
FM-200® design concentrations should be calculated according to the lowest expected ambient temperature
within the protected area. When calculating the concentration levels for normally occupied spaces, the
design concentration for FM-200® must not exceed the NOAEL (No Observed Adverse Eect Level) of
9% at the highest expected ambient temperature as stated in NFPA 2001.