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Thread: Electrical cable routing
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06-05-2007, 02:10 PM #1
Electrical cable routing
Last edited by Jeff Eastman; 12-19-2007 at 08:53 PM.
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06-05-2007, 08:31 PM #2
Re: Electrical cable routing
Technically, yes, but no.
All those cable going through that one hole could overheat and cause a fire.
A few years ago I found something by one of the major wire companies (I think it was) which reported several fires due to this practice.
That's also a poor attempt at 'maintaining spacing' and those will need to be derated (because there are two cables 'bundled' under each staple and which (looks like) is for greater than 24". There are 4 current carrying conductors under each staple.
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06-05-2007, 08:39 PM #3
Re: Electrical cable routing
September-October 2003: Ambient Temperature Ampacity Corrections for Cable Bundling and Direct Solar Exposure
"The bundling experiment involved electrical loads in two each of 14 AWG, 12 and 10 Type NM-B cables, two conductors with ground, a total of 12 loaded conductors. The cables were routed through a 1-1/2 inch vertical hole in a wood top plate that was then fire-stopped. The cables were all loaded in increments up to 80 percent of their design loads (up to 12, 16 and 24 amps, respectively). In combination with high outdoor temperatures, the cables reached temperatures as high as 233°F (112°C) at the limit of 80 percent continuous loading, well above the design limit of 194°F (90°C) for these cables, constituting a clearly dangerous environment."
And there were fewer cables here than in that photo.
Here is another one about the same thing:
http://www.copper.org/applications/e...ion_report.pdf
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