Records 1056 to 1057 of 1057
Andrew T. Hills, Terence Simpson, David P. Smith
Although water is known to be an effective Class A and B fire suppressant, skepticism remains over its use in Class C applications due to its conductivity. Therefore, a joint Kidde-Fenwal/GTE/FSI Research feasibility study into water mist fire protection in live telecommunication switch gear was carried out.
The switch gear bays, which were composed of vertically mounted, parallel printed circuit boards (PCBs), were found to be a considerable fire threat. A localized “in cabinet” fire suppression system comprising single fluid spray nozzles operating at high pressure was used. Test fires were extinguished in 1-2 seconds using less than 1 L (0.26 US gal) of water. In addition, the current trips contained in the switch were activated when water was incident and this result, coupled with the low volume of water used, reduces the electric shock hazard considerably.
Therefore, water was found to be an efficient and safe fire suppressant in switch gear. Since these initial experiments, further tests have been carried out on alternative equipment supplied by Mercury Communications, for which findings are briefly presented.
Charles D. Storrs
Fuel, oxygen, and heat sufficient to raise the material to its ignition temperature must be presented to produce a flame. The effect the fire-retardant system will have on each of these components must be considered during the development of effective fire-retardant polymer formulations.