![]() When exposed to an arc flash there are two main things you need to be protected from. The technology in protective arc flash clothing has come a long way in the last 15 years including the arc flash suit material. you'd probably walk away without a scratch. Meaning, if you were wearing the proper protective clothing. Watch This Arc Flash VideoĪll jokes aside though, there are no known cases of a fatality caused solely by the arc blast of an arc flash. There are even some people who argue that the blast will actually help you by moving you out of the vicinity of the arc flash (unless you are one of those arc flash manikins. This is mainly because time is a factor in arc flash calculations and not a factor in blast calculations. There is no saying that the blast on a 10 cal/cm2 arc flash will be any higher or lower than a blast on a 40 cal/cm2 arc flash. You also can’t tie the blast to the incident energy. But the Arc Blast Will Kill You!īut a 1.2 cal/cm2 arc flash can kill you too (in theory). The trouble is that it doesn’t really tell us what to do… it just sounds scary. Finally, material and molten metal are expelled away from the arc at speeds exceeding 1100 km/h (700 mph), fast enough for shrapnel to completely penetrate the human body. The high pressures can easily exceed hundreds or even thousands of pounds per square foot, knocking workers off ladders, rupturing eardrums, and collapsing lungs. The danger associated with this expansion is one of the high pressures, sound, and shrapnel. For example, copper expands by a factor of 67 000 when it turns from a solid to a vapour. The tremendous temperatures of the arc cause the explosive expansion of both the surrounding air and the metal in the arc path. In fact, there is only this excerpt from an appendix in CSAZ462 that even really talks about arc blast at all. There have been a couple of attempts of how to calculate the blast pressures but there is nothing officially listed in the CSAZ462 or the NFPA70E documents. Which oddly enough is not measured or calculated. The other thing they didn’t do a very good job explaining was arc blast vs arc flash.Īrc flash is what the 40 cal/cm2 is referring to… it’s a measurement of heat energy (imagine it as the electrical arc flash temperature).Īrc blast is the associated blast pressure from the arc flash event. “the blast will throw you across the room”ĬSAZ462 reads the rating as, “the value attributed to materials that describes their performance on exposure to an electrical arc discharge.” Simply put, for arc flash suits, the material has been tested at certain arc flash levels creating an arc thermal protective value.“over 40 calories the blast will make your bones turn to mush”.“at 40 calories if the heat doesn’t kill you, the blast will”.there was no talk of 100cal arc flash suits… so people started speculating. There was also a note in the standard that said you needed to take extra precautions when the incident energy is greater than 40. This is where it all started with the 40 cal/cm2. and the corresponding clothing was rated 4, 8, 25, and 40 cal/cm2 (or ATPV rating). The categories that were developed were 1, 2, 3, and 4 (very creative). One way was to come up with different categories of clothing that could protect a worker from certain levels of arc flash heat energy (Incident energy). The 100 cal Arc Flash Suit & the 40 cal Mythīack when the electrical safety and arc flash standards were first being developed the arc flash protection clothing manufacturers needed a way to simply organize the hazard levels. Arc Thermal Protection Class (APC): class 1 (4 kA).FREE DOWNLOAD: DEFINITIVE GUIDE TO AF STUDIES.Pictograms of standards visible on the outside of the garment. ![]() Central closure with an anti-panic zip covered by a flap closed by scratch.Composition: 80% flame retardant treated cotton / 19% polyester / 1% anti-static.Fabric combining safety, comfort and resistance over time thanks to the combination of a proven composition and construction.MULTI-RISK PROTECTION : CAT'ARC clothing offers multiple protection to wearers who are exposed to the thermal risks of electric arcs, heat / flames, welding and electro-static.ĭAILY COMFORT : The fabric and design of the garment has been selected so that wearers can wear the garments for a full working day.
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