Installed a 200amp panel 3/0 service feeder and the service drop was #4 AWG AL. Called up National Grid and they put in a #2 AWG AL 150A. Looking at 310.60 table 310.15 B 17 and think it should it be a #1 AWG AL 175A service drop. Am i missing something or do they not follow the NEC verbatim?

I have an electricity bill of the whole year, from that how can I know how many maximum amps are consumed in a single day, I am looking for an answer the client wants to make sure that the new changes and addition of equipment will not affect the current panel board to be changed, the store is...

what does 240.4B2 mean? here's an example: 1/0 XHHW is rated for 150amps. we have air conditioner [or whatever] with a actual load 125 amps. 125% of 125 amps = 156 amps but these is no such breaker. if the next higher breaker is 200A, would I be allowed to use that? this is an example only...

Hello, folks: I must take an examination on Friday and am struggling a bit with problems pertaining to ampacities and to the proper procedure for derating ampacities. I show below a sample problem and my proposed solution. I would like to know whether or not the proposed solution is correct...