450amp main disconnects on a 250amp service, is this OK?

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Pittsburgh

New User
Location
Pittsburgh
Occupation
Contractor
I would love to get a few opinions if this is OK and maybe a few ideas on how it should be corrected if this is an issue. We’re starting a basement remodeling project and the incoming service totals 250 Amps at the meter, but three breakers that are installed inside the house that are capable of up to 450 amps total. However, each of those breakers is below the 250amp limit (200, 150, 100), are installed to code, and the sum total of the does not exceed 250Amp total. The main panel has a 200amp main breaker feeding (1) 150amp sub-panel and (1) 100amp sub-panel. Is this configuration OK? Thank you!
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
It is impossible to tell without a load calculation. The sum of the breakers don't mean anything. The main service is only 200 amps since the main breaker is 200 amps. What you have could be just fine.
 

kwired

Electron manager
Location
NE Nebraska
You could have a 200 amp main breaker and supply 1000 amp gear from it - the 200 amp breaker still trips if you load it to more than 200 amps, if you never have more than 200 amps of load, there is nothing code wise to reject the installation.
 
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