Table 310.15 B 16 question - 4/0 Cu for 200 amps

In a 1979 office building, they have 4/0 Cu conductors for 200 amp service panel (single phase). It looks lile 3/0 would have been fine. Just a question for someone who does not do many commercial jobs. Thank you.
 

augie47

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Staff member
Location
Tennessee
Occupation
State Electrical Inspector
Several possibilities, could be a 60° conductor or 60° termination ratings. or voltage drop issue.
Likely just over-engineered.
 
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