Does Having 480VAC Run Through a Panel Increase its NFPA70e Rating?

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nesterline Active Contributor Join Date: Oct 2010 Posts: 16	Does Having 480VAC Run Through a Panel Increase its NFPA70e Rating? 02/21/2013 11:12 AM
	Does having 480VAC run through a panel increase its NFPA70e rating? I am working with a vendor that wants to run a high voltage wire (480VAC) through a 24VDC panel to reach another 480 panel. The wire will not terminate in the panel, but will run through the tray in the low voltage panel. Will having that wire in the panel increase the energy level and by that increase the category of the panel? Thank You,
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	Pathfinder Tags: arcflash category high voltage nfpa 70e panel

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cuba_pete Guru Join Date: Dec 2010 Posts: 1895 Good Answers: 44	#1 Re: Does Having 480VAC Run Through a Panel Increase its NFPA70e Rating? 02/21/2013 3:29 PM
	Does the NEC apply to you? High voltage under the NEC does not begin until 600VAC, nominal, between conductors and ground. 480VAC between conductors or between conductors and ground? NEC 312.8 applies to feed-through conductors. Panelboards are rated for voltage, enclosures are typically rated by location. There is much more which could apply to each specific instance. What category are you speaking of?
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JRaef Guru Join Date: Sep 2006 Location: California, USA, where the Godless live next door to God. Posts: 4665 Good Answers: 804	#2 Re: Does Having 480VAC Run Through a Panel Increase its NFPA70e Rating? 02/21/2013 5:38 PM
	NFPA 70E has to do with Arc Flash and electrical safety issues. nothing in those specs addresses whether or not the power is terminated in an enclosure or not, only that it is present. But simply sectioning off a part of your enclosure as "wireway" changes that issue. You also have a code issue in that if you bring 480V conductors in the same wiring space, ALL conductors must have the same insulation level as the highest voltage in the enclosure. So all of your 24VDC controls will need to be wired with 600V rated wire, including any communications cables (if any). That may prove to be problematic. Put a separate gutter on the bottom, keep them totally separate, no issues. __________________ All I every really wanted to be, was... A LUMBERJACK!.
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bfmickl Associate Join Date: Jan 2007 Location: Raleigh, N.C. Posts: 49 Good Answers: 1	#3 Re: Does Having 480VAC Run Through a Panel Increase its NFPA70e Rating? 02/22/2013 1:53 AM
	Another item to consider is your area fill for this panel. See NEC 409(A). 2011. __________________ "You can fool some of the people all of the time and you can even fool all the people some of the time, but you can never fool all the people all of the time." Abe Lincoln
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