Sceneario..... Exterior meter can has a 100 amp disconnect feeding a panel board in the interior with a 200 amp main disconnect. All feeders and service entrance conductors are sized for a 200 amp service. Is this a code violation? If so, what section? 2005 NEC. I think its code compliant but not sure which section to reference.
OCPD Sizing
- Thread starter VIC1958
- Start date
- Status
- Location
- Massachusetts
You won't find anything saying it is OK, but at the same time you will not find much saying it is not.
About the only code violation I can think of would be if the calculated load is over 100 amps.
About the only code violation I can think of would be if the calculated load is over 100 amps.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Yes but I thought you said the meter had a 100 amp main feeding the 200 amp panel. If that is so then the 100 main should trip if it is overloaded
- Location
- Massachusetts
If the calculated load is over 100 amps using a 100 amp disconnect* is a violation.
If the 100 amp disconect would trip or not is another story, the calculated load could be above 100 amps without the actual connected load being over 100 amps.
*By the way, I assume the 100 amp disconnect is fused or is a breaker?
MarineTech
Member
- Location
- Camarillo, CA
What type of disconnect do you have? CB? Switch+Fuse?
Did you do a load calculation?
I do not have a old 2005 NEC.
For me the intent of 2011 NEC 220.40 is clear as it relates to the calculated load. If the calculated load is greater than 100A then it has to be supplied.
Did you do a load calculation?
I do not have a old 2005 NEC.
For me the intent of 2011 NEC 220.40 is clear as it relates to the calculated load. If the calculated load is greater than 100A then it has to be supplied.
Sorry for the confusion here, my wording might be misleading. This is an existing single family home. Meter can on the outside is a combo unit with meter and a 100 amp breaker feeding a 200 amp panel in the interior with a 200 amp breaker installed. I have no idea what the load calcs are on this. Sooooo that being said, it would be safe all the way around to put a 200 amp breaker in the meter can to replace the 100 amp. Correct? The only way to allow the CURRENT configuration would to do a load calc and prove that it would be under the 100 amp threshold.
- Occupation
- Licensed Electrician
No. Your fine with what you have.
- Status