How to size conductors for DC voltage?

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necnotevenclose

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I'm looking at a project where I need to size the conductors based on 3000A @ 48VDC. Looking in the code book I don't see a seperate table for DC conductors. That leads me to believe that I use 310.16. Is that correct?

Thanks in advance for your replies.
 

G._S._Ohm

Senior Member
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I'm looking at a project where I need to size the conductors based on 3000A @ 48VDC. Looking in the code book I don't see a seperate table for DC conductors.
AC RMS value = the DC value as far as heating, by definition.

With DC there is no skin effect or proximity effect so the Neher McGrath equation reduces to a simpler form.

I'd think with only 48 VDC you can use thinner insulation, which decreases the thermal resistance of the insulation, and so you have a higher amb. temp or higher current or both. This detail may not be in the code.
 
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