# Difference between Tables 310.16 and 310.17



## swimmer (Mar 19, 2011)

Can someone please explain the difference between tables 310.16 and 310.17? I've been able to determine, through web search, that 310.16 applies to services and feeders while 310.17 pertains more to branch circuits but I could really use a few examples on how to apply these 2 tables.

Thanks


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## raider1 (Jan 22, 2007)

Table 310.15(B)(16) (2008 and earlier NEC Table 310.16) Shows the allowable ampacity of insulated conductors rated up to 2000 volts with not more than 3 current carrying conductors in a raceway cable or earth.

Table 310.15(B)(17) (2008 and earlier NEC Table 310.17) Shows the allowable ampacity of single insulated conductors rated up to 2000 amps located in free air based on an ambient temperature of 87 degrees F.

So if your wires are in a cable, or raceway or direct buried in the earth then you would use Table 310.15(B)(16).

Chris


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