Residential feeders

C

chicagosparky

Member
Location
Chicago, IL
Have a question concerning a new service for a 3700 sq ft single famly home. I did the load calc & came up with 191 amps of connected load for the home. As I am aware, you can only load a service 80 % of it's main disconnect so a 200 amp service won't cut it. If we install [2] 200 amp panels side by side both connected to the local utility meter cabinet which has a 320 amp rating, do I size the feeder conductors per load [191 x 1.2=228 amps] which 300 MCM would work; or do I use the meter rating of 320 amps which 500 MCM feeders would work.
The meter can does not have a main disconnect, just the [2] panels both have 200 amp MCB's.
 
chicagosparky said:
Have a question concerning a new service for a 3700 sq ft single famly home. I did the load calc & came up with 191 amps of connected load for the home. As I am aware, you can only load a service 80 % of it's main disconnect so a 200 amp service won't cut it
Click to expand...
This is incorrect. You do not need to apply an 80% limit on the service. A 200 amp service is code compliant as the minimum size required based on your load calculation.
 
chicagosparky said:
Have a question concerning a new service for a 3700 sq ft single famly home. I did the load calc & came up with 191 amps of connected load for the home. As I am aware, you can only load a service 80 % of its main disconnect so a 200 amp service won't cut it. If we install [2] 200 amp panels side by side both connected to the local utility meter cabinet which has a 320 amp rating, do I size the feeder conductors per load [191 x 1.2=228 amps] which 300 MCM would work; or do I use the meter rating of 320 amps which 500 MCM feeders would work.
The meter can does not have a main disconnect, just the [2] panels both have 200 amp MCB's.
Click to expand...
according to 230.79 a 200 amp service is all you need if your load calculation is correct
 
If you want to provide for future loads there is no problem with your supplying two panels off the meter feeding each with 3/0 cu or 4/0 AL
 
You must log in or register to reply here.
Top