Kidde Fire Systems Natura, Owner'S Manual

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General Information
P/N 06-237620-001 1-3 June 2020
1-3 ABOUT THE SYSTEM
The fire suppression system is designed for suppression of the fire classes listed in Table 1-1.
Different standards have different fire classifications.
1-4 AGENTS OVERVIEW
Natura IGS systems are approved for use with the following four Agents:
•
IG-100: Fixed fire extinguishing systems that use the pure inert gas Nitrogen
• IG-541: Fixed fire extinguishing systems that use inert, gaseous mixture of 52% Nitrogen,
40% Argon, and 8% Carbon Dioxide
• IG-55: Fixed fire extinguishing systems that use inert, gaseous mixture of 50% Nitrogen
and 50% Argon
• IG-01: Fixed fire extinguishing systems that use the pure inert gas Argon
The gases used in Natura IGS systems occur naturally within the earth’s atmosphere. Carbon
Dioxide constitutes approximately 0.04%, Nitrogen constitutes approximately 78%, and Argon
approximately 0.9% of the atmosphere. As a result, the global warming effect of the Natura
IGS systems is zero, the Ozone depleting factor is zero, and the atmospheric lifetime is not a
consideration as the gases are benign to the environment.
1-4.1 Agent Safety Concentrations
Natura IGS agents are used at relatively high concentrations to extinguish fires, typically in the
range of 40 to 50% agent in air, or more. At a Natura IGS agent concentration of 45%, the
residual oxygen concentration is 11.5%, compared with 21% in normal air. The principal health
risk from exposure to atmospheres having such low oxygen concentrations is "hypoxia,"
meaning insufficient oxygen concentration in the blood. The resulting guidelines for exposures
to atmospheres flooded with Natura IGS agents are as follows:
•
Unnecessary exposure to Natura IGS agent systems resulting in low oxygen atmospheres
shall be avoided.
• The maximum exposure time in any case shall not exceed 5 minutes.
• Unprotected personnel shall not enter the area during or after Agent discharge.
The following additional provisions shall apply:
•
Natura IGS systems designed to concentrations below 43 percent (corresponding to an ox-
ygen concentration of 12 percent, sea level equivalent of oxygen) shall be permitted where
means are provided to limit exposure to no longer than 5 minutes.
• Natura IGS systems designed to concentrations between 43 and 52 percent (correspond-
ing to between 12 and 10 percent oxygen, sea level equivalent of oxygen) shall be permit-
ted where means are provided to limit exposure to no longer than 3 minutes.
Table 1-1. Fire Classifications
Description
European
Standard
NFPA
Standard
Asia
Combustible materials (wood, paper, fabric, refuse) Class A Class A Class A
Flammable liquids Class B Class B Class B
Flammable gas Class C Class B Class C
Electrical fire not classified
(formerly Class E)
Class C Class E