Sizing Service Entrance Conductors

[frank_n]

I'm sizing the SE conductors for a 100 amp service. According to Table 310.15(B)(6) I can use #4 copper. Table 250.66 allows #8 copper for the neutral (grounding electrode conductor). Am I interpreting this correctly? Is this good practice?

Also, how much does the permit for a service usually cost?

Frank_N

 

[infinity]

Yes, if 310.15(B)(6) is applicable to your installation. The GEC would be based on table 250.66 and your service entrance conductor size. One note, a #8 GEC would be required to be in a conduit or cable armor. A #6 could be run exposed where not subject to physical damage.