Clean Agent Suppression of Energized Electrical Equipment Fires

Abstract

The NFPA 2001 standard on the use of clean agents for the suppression of fires arose from the phase-out of Halon 1301. Standard methods exists for specifying the amount of clean agent required for Class A and Class B fires, but the recommendation for Class C fires (those involving energized electrical equipment) defaults to the Class A values. While this may be appropriate for some Class C fires, there is concern that higher agent concentration may be necessary if energy is added to the fire by the electrical source. A number of test methods have been proposed to determine the amount of agent required to suppress fires in energized electrical equipment; however, there has been no broad agreement on a test method to include in NFPA 2001 for Class C fires. Further, some of the test methods suggest that the current recommended total flooding concentration is sufficient, while others suggest that higher concentrations may be necessary for some fires. This report reviews the role of energy augmentation in the suppression of fires over condensed phase materials. A test protocol is suggested which can quantify the effects of added energy on the suppression process.

Ignition and Flame Propagation of Externally Heated Electrical Wires with Electric Currents

“…Fujita et al [19] also studied the effect of gravity on the ignition of electrical wire with short-term excess electric current and found out it was easier to obtain in microgravity than under normal gravity. Linteris [20] summarized the effects of configuration, polymer insulation, separation distance, etc. on the energized electrical wire fires.…”

Comparison of fire extinguishing performance of four halon substitutes and Halon 1301

“…20 Based on these requirements, we selected HFC-227ea, inert gas (IG-541), solid particle hot aerosol (ql200) and Novec 1230 for this study. 21,22 Because of the limitation of test conditions, we can only select a limited number of representative and commercial fire extinguishing agents which were widely applied for test comparison. The test results are effective for the fire extinguishing agents used in this article.…”

Effect of ecologically safe gas-aerosol mixtures on the velocity of explosive combustion of n-heptane

“…In such cases, the explosion front might propagate at the corresponding velocity, which may lead to a partial or complete destruction of the equipment through creation, in this case, of the elevated pressure. It is known that the fire extinguishing concentration of СО 2 for most hydrocarbons is about 21 %, and retarding concentration is about 30 % or higher [1][2][3][4]. For nitrogen, these values are, respectively, for n-heptane (С 7 Н 16 ) 33.6 % [4,5], and retarding concentration of N 2 is 43.9 %, which is 3-4 times as high as the retarding concentration of khladons [5].…”