200A service

[Hfalz1]

I have a 200A service just wondering if i can go down to a 2/0 thhn size wire. 2/0 is rated 195A and 3/0 is 225A.

 

[jumper]

That is the 90C column and you are going to be limited to the 75C at best.

 

[Smart $]

You can if a service for individual dwelling units of one-family, two-family, and multifamily dwellings. See 310.15(B)(7) for details.

 

[Steeler5]

I have a 200A service just wondering if i can go down to a 2/0 thhn size wire. 2/0 is rated 195A and 3/0 is 225A.

See article 110.14 (C)(1) anything over 100a is limited to 75 degree column unless you can prove all of your connections are rated for the 90 degree termination. I have yet to see a standard breaker rated over 75 degree terminals.


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[electrofelon]

I have a 200A service just wondering if i can go down to a 2/0 thhn size wire. 2/0 is rated 195A and 3/0 is 225A.

Most likely yes. As mentioned if it's a dwelling unit, you get to use smaller wire. Also the next size up rule comes into play which allows 176-199 amp wire on a 200 amp main breaker as long as it exceeds the load calc.

 

[Smart $]

Most likely yes. As mentioned if it's a dwelling unit, you get to use smaller wire. Also the next size up rule comes into play which allows 176-199 amp wire on a 200 amp main breaker as long as it exceeds the load calc.

But you cannot obtain the 176 as the cap for a 75°C termination of 2/0 copper is 175A.

 

[electrofelon]

But you cannot obtain the 176 as the cap for a 75°C termination of 2/0 copper is 175A.

Yes I concur (that second part was meant to more of a general comment. Should have made clear it didn't apply to the op's specific situation)

 

[infinity]

I have a 200A service just wondering if i can go down to a 2/0 thhn size wire. 2/0 is rated 195A and 3/0 is 225A.

You have to comply with the section Smart posted otherwise the answer is no.