Meter base size

Meter base is not square, is this a 200 amp base?
Service panel is rated at 125, conductor to service panel is rated 125, main breaker is 125. Service to meter is not visible.


The only way to know for sure is to look inside the meter can, which is pretty much a non option for most.

According to the NACHI Electrical Course, which says a square meter base is 100 amp and a rectangular meter base is 200 amp, this should be a 200 amp base. Any refutations?

It does not matter. The system is only as big as the smallest component.

Yes, this assertion is absolutely false.
That IS a 100A meter pan. I only know this from experience. Others may not know just from looking at it.

James is 100% correct. It would not matter a lick if that were a 200A meter pan. While everything is “rated” at 125 amps I bet the main breaker still says 100A.
It’s a 100A service.

Pepco (DC/Md/Va) installed a 200a service in that type of meter base in the 70s.

I agree the system is only as big as the smallest component. The original post states everything else including the main breaker is 125. My concern is the meter. If it is only 100, then the system is 100. If it is 200, the system is 125.
According to the NACHI course it is 200. Some don’t agree with this. I’m seeking input regarding the meter size to size the system.


I like to look at the local utility rules, here is a file in you area I found that may be of help:

Meter Base

More here too: Milbank

You can find information here as well:

I would say watch my online video regarding it. You can’t assue anything based on the meter can…plus its a POCO thing…so exclude it and go with what is known…Panel Rating, Conductors Size and OCPD size…those factors based on the weakest link theory is the method to use…remember the meter can is part of the analysis…and may lead to confirmation of the other 3 items…but alone never rely on the meter can…

The online course helps you understand concepts and general sizes but is only a stepping stone to the entire process.

This is excellent advice.