RE: Power distribution -Electric Arc Flash–Are we safe ???

Former Member — Thu, 18 Mar 2010 00:58:16 GMT

Well, don't take this the wrong way. I can tell this was not written by an electrician. There are multitutes of PPE for arc flash protection. So much so the the NFPA, pulisher of the NEC (nfpa70) wrote a thick book of the subject and the standard is set forth in NFPA-70e, electrical saftey in the workplace. It's a large book that is at least 800+ pages. Utility workers are also subject to PUCA. The biggest problem is complience, not one wants to wear an arc flash suit in the summer. So they try to do as much as then can with out it on, then don it as needed. This is every industry you can make saftey devices that work, IF THEY WEAR IT!

Lets look at some numbers, we all love that right!

Arc-flash temps: 11,0000 deg. F, or 6,000 deg. C, almost the same as sun's corona.
Copper expands to 67,000 times it's volume when vaporized
Oxy-hydrogen flame: 2000 °C or above (3645 °F)
Bunsen burner flame: 1,300 to 1,600 °C (2,372 to 2,912 °F)
Blow torch flame: 1,300 °C (2,370 °F)
candle flame: 1,000 °C (1,830 °F)

Considering this I don't think 20% containment is impressive, It's a start.

For more info try google: arc flash copper expands when vaporized"

Here are a few links if you can wait:

http://www.allbusiness.com/manufacturing/plastics-rubber-products/4073821-1.html

http://www.littelfuse.com/data/en/Arc-Flash_Hazards__Electrical_Safety/LittelfuseArc-FlashTechBrief-PF9801.pdf

http://www.e-t-c.com/pdfs/Arc%20Flash_web.pdf