Hfalz1
Member
- Location
- Houston, Tx.
- Occupation
- Electrician
I'm told i can use 2/0 cu THHW for a 200A service. Why is this if according to table 310.15 (B) (16) 2/0 is rated 175A?
200A wire sizing
- Thread starter Hfalz1
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electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
- Occupation
- Electrician
See 310.15(B)(7) for dwelling unit services.
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
This:
But it is limited to conductors that supply the entire load to a dwelling. Reasons have to do with load diversity of a dwelling, they are saying if it supplies the entire dwelling load the chance of it ever drawing full 200 amps (even if load calculation was 200) is not that great so they allow some reduction in conductor size. Don't ask me how they come up with the 83% that they settled with though.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Is it a dwelling?
Hfalz1
Member
- Location
- Houston, Tx.
- Occupation
- Electrician
- Location
- Connecticut
- Occupation
- Engineer
Yes, 2014 Code. Right between 310.15(B)(6) and 310.15(C).
Hfalz1
Member
- Location
- Houston, Tx.
- Occupation
- Electrician
it is not a family dwelling.
Sierrasparky
Senior Member
- Location
- USA
- Occupation
- Electrician ,contractor
If not a dwelling than you can't use that rule!
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
You need 3/0 copper. A residence has an exception that allows 2/0 copper for a 200 amp service. To be more exact I mean a single family dwelling single phase 120/240v.
This section mentioned above is not a table but a written section that allows the deduction
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