Hi, I am the homeowner and general contractor for our renovation project. I'm looking to better understand large amperage services. I've had multiple different recommendations from electritians.
We have a fairly unusual situation. When we bought we had 200 amp service to the house, 100 amp service to the detached garage, and 150 amp service to the coach house above the garage. There was also a transformer from the power company on our property. The transformer needed to be relocated to remove an underground fuel oil storage tank. The PC agreed to relocate the transformer but would only provide service to the house, running new service to the outbuilding would be our responsibility. Our electrician recommended we get 600 amp service to match the existing total supply of 450 and to prepare for the renovations we were planning (EV chargers, 2nd air conditioner, electric stoves, and dryer).
That work is now complete.
We have a large CT meter box with 1000kcmil wire service from the PC and parallel 300kcmil lines running to a 600 amp rated power distribution panel. That power distribution panel has 3 200 amp breakers that feed 3 200 amp panels (1 in the coach house/garage and 2 in the house) using 3/0 wire. There is no main breaker like in typical panels.
The garage has a 200 amp panel with a 100 amp sub panel in the coach house.
We are adding on a second outbuilding with will be my automotive man cave (welder, lift, etc). I would like to run an additional service from the 600 amp box to the workshop.
Is it normal not to have a main breaker in a distribution panel?
Should there be a main disconnect between the distribution panel and the CT meter box?
Is the service from the meter box protected from over-current by the sum of the 200 amp breakers?
If that is the case, I assume that we can not add an additional 200 amp breaker and would have to replace them with 4 150 amp breakers?
I've done the load calcs and can 4 150 amp panels would work. Another option is to add an additional 100 amp sub-panel of the garage for the workshop instead of another home run.
We have a fairly unusual situation. When we bought we had 200 amp service to the house, 100 amp service to the detached garage, and 150 amp service to the coach house above the garage. There was also a transformer from the power company on our property. The transformer needed to be relocated to remove an underground fuel oil storage tank. The PC agreed to relocate the transformer but would only provide service to the house, running new service to the outbuilding would be our responsibility. Our electrician recommended we get 600 amp service to match the existing total supply of 450 and to prepare for the renovations we were planning (EV chargers, 2nd air conditioner, electric stoves, and dryer).
That work is now complete.
We have a large CT meter box with 1000kcmil wire service from the PC and parallel 300kcmil lines running to a 600 amp rated power distribution panel. That power distribution panel has 3 200 amp breakers that feed 3 200 amp panels (1 in the coach house/garage and 2 in the house) using 3/0 wire. There is no main breaker like in typical panels.
The garage has a 200 amp panel with a 100 amp sub panel in the coach house.
We are adding on a second outbuilding with will be my automotive man cave (welder, lift, etc). I would like to run an additional service from the 600 amp box to the workshop.
Is it normal not to have a main breaker in a distribution panel?
Should there be a main disconnect between the distribution panel and the CT meter box?
Is the service from the meter box protected from over-current by the sum of the 200 amp breakers?
If that is the case, I assume that we can not add an additional 200 amp breaker and would have to replace them with 4 150 amp breakers?
I've done the load calcs and can 4 150 amp panels would work. Another option is to add an additional 100 amp sub-panel of the garage for the workshop instead of another home run.
