Safety is taking a back seat to $$$

[mbrooke]

That how I interpret it. To be honest the rule could really use a change. Most use the next size up anyways.

 

[jmellc]

4/0 aluminum can be protected at 200 amps without the residential exception via next size up rule. Connected load can not be more than 180 amps though. Besides your inspector wasn't right on wanting 150 amp breaker, 175 is a standard size, but 4/0 should still been fine on a 200 as long as load calculation was 180 or less.

Inspector didn’t ask for a load calculation, just disallowed 200 A on 4/0 AL because of the outdoor receptacle. Supply house had some 150 A main breakers & generously traded me one at no cost. I didn’t even think to ask about a 175 as I have never seen a 175 main that I recall. I was lucky they had the 150.

 

[kwired]

Inspector didn’t ask for a load calculation, just disallowed 200 A on 4/0 AL because of the outdoor receptacle. Supply house had some 150 A main breakers & generously traded me one at no cost. I didn’t even think to ask about a 175 as I have never seen a 175 main that I recall. I was lucky they had the 150.

150 works, presuming load calculation was 150 or less. I was stating that your inspector was wrong if he demanded a 150 when 175 is a standard size. but sounds like he was still wrong because that 4/0 aluminum can be protected at 200 amps per the next size rule as long as load calculation is not over 180 amps. (the actual ampacity of the 4/0 aluminum)