Service Capacity

The service conductors were #2 copper, the main panel and main breaker were rated at 100 amps, and the meter was rated at 200 amps. I don’t see very many of the smaller round meter bases, so I thought I would get some confirmation from the pros on this BB. I believe that is a 60 amp rated meter base, which makes the service capacity 60 amps. Upgrading the meter base would make the service capacity 100 amps. Is that right?

Be careful. According to one of our local (very knowledgable) electricians, there were quite a few 100 AMP round meter bases produced. There are no obvious markings on the exterior of the base, though.

If the panel is 100 AMPs, I state that it is likely 100 AMPs, but there is a possibility that it is only 60 AMPs, they need an electrician to determine which if it is a concern.

I’d call that a 100 amp service…BUT I never even dreamt of checking the actual meter BASE?:shock: I know they are old and watch for wire protection and height requirements as we usually see upgrades are necessary or will be on their next reno project involving electrical work.

Learn something new every day…WOW


 Many times they increase the size of the conductors but that ends up being where they stop. You have to understand while the conductors have a capacity of 200A the limiting factor on the system is the lowest rated in the setup.

In this case if the OCPD is 100A and the Panel's rating is not rely on the round meter can...back in the DAY they even approved round models for 100A better to use the factors you know and that would be the Service Enclosure and the size.....

My house in Md also had a 200a service using the small square meter can. You really can’t prove much by what a PoCo will allow.

No doubt Greg…While in some cases it can be a piece to the puzzle…the use of the meter can should never be the determining factor. With experience it can aid in your process but in older homes it just can aid in getting the HI confused.

Great info. Thanks Paul and Greg.

The real issue with meter bases is not volume, it is wire bending space. They make the bigger ones so you can enter at the bottom and have enough room to loop into the top lugs of the meter base. If it is 4/0 or less and you go straight into (45 degree bend or less) “lay in” lugs you only need 4".