Service or feeder rating of NM 2-3 on NEC 310.60

[sungreentech]

Hi: working on replacement of feeder from main to sub panel.

it's 40 years old house, underground feed, 100A with breaker/combo meter connect to sub panel with #2-3 w/ground Aluminum.

If I can upgrade to NM 2-3 copper Romex but include all type THHN, THHW #2copper all has 95 amp rating but according NEC 310.60 feeder type copper #2 has 125 amp.

my question is it correct to use Romex 2-3 to replace my Aluminum 2-3? obviously it's better, but how would I convinence Elec inspector that it's good for 100 amp? because 310.60 does not list NM type wire.

Thanks a lot
Paul

 

[augie47]

Unless your house is operating at 2001-3500 volts, 310.60 does not apply .
If you are using #2 Cu Romex on interior wiring under the '08 Code your amapacity is 95 amps. With (and possibly without) a load calcuation, the inspector should allow that on a 100 amp breaker.

 

[Dennis Alwon]

Look at art. 240.4(B). If the calculated load of the house is 95 amps or less than you can use the next higher breaker. Remember nm cable is limited to 60C-- see article 334.80. Table 310.15(B)(6) will not allow nm cable

Gus I think he means Table 310.16.