difference NEC Table 310.15(B)(16) and (17)

[AAGR2013]

the table in NEC2014 is always referenced to find out the conductor capacity. I am still not sure the difference by reading the title of table.

 

[knight1fox3]

The first table is for current-carrying conductors in raceway, cable, or earth.  The second table is for current-carrying cables in free air (e.g. connecting power dist./control panels together).

 

[AAGR2013]

thanks, free air seems to be wire/cable is not in tray, conduit... I assume it runs in short distance because there is no support. 

 

[TWJ PE]

thanks, free air seems to be wire/cable is not in tray, conduit... I assume it runs in short distance because there is no support. 

Don't think of it that way....