How is this determined reportable size service supply

Here are a couple of examples:
Example #1:
A 200-amp service lateral,
a 200-amp meter and base,
a 175-amp-rated SEC,
a 150-amp-rated panel, and
+ a 125-amp service disconnect
= A 125-amp reportable service supply

Example #2:
A 150-amp service drop,
a 60-amp meter and base,
a 150-amp SEC,
a 100-amp-rated panel, and
+ a 100-amp service disconnect
= A 60-amp reportable service supply

IMO the meter has no bearing on determining the service size. In example #1 I agree 125 amp service based on the 125 service disco. In example #2 how could you use a 60 amp meter enclosure with a 100 amp service?

In example #1 you said that there is a 200A service lateral. Do you mean the service lateral conductors from the utility company? How are you determining the ampacity?

In example #2 you said that there is a 150A service drop? How are you determining the ampacity?

Greetings Folks,

Sometimes questions do not have to totally make sense to convey the proper message. In the examples shown the OP has correctly stated the rating of the service in terms of the information provided. Sometimes we want to equate theoretical questions with real life situations…ignore that aspect of the question and take the values at face value.

The OP is using the weakest link method of determination of the service based on given (assumed known) information. In the real world it wont be that simple and in some cases you will only have 2 or 3 of the key factors to rely on…but usually the signs are evident if you just look for them.

Now the questions - The answer to A is indeed 125A as that is the limiting factor. In the second example, it would appear that the meter base is the limiting factor. However, there are indeed (real world creeping in now) some meter enclosures that are 60A and/or 125A depending on the time frame and since the physical nature of the meter was not expressed…we have to assume they validated this fact.

Now…the bigger message here to an HI is this. If in example 2 you notice the situation it is fairly observant that either an unauthorized upgrade took place (based on the given example parameters) or someone is mistaken about the meter size and ratings. So with that said it would be customary to question that fact on your report.

However, if you are unclear on the meter (and at this point no physical attributes are given, so I may disregard it) I would not loose sleep over rating it a 100A with an explanation again of the meter situation. Either way you have conveyed the message to the customer that is needed in a truthful and accurate depiction.

Just my thoughts on the subject.

Hi Paul,
Always great to see you weigh in on these posts. There’s been a few discussions lately (here and in other forums) about the meter base being part of the service size calculation. Most say it’s not part of the calculation, I was originally taught it was. If you have one of the old round meter bases (60A), is that a limiting factor if everything else is 200A? Or is this a sign that things may not have been upgraded under a permit. I do see a lot of CL200 meters in 60A bases.


IMO you cannot determine the size of the service with the parameters you’ve given. If everything is rated for 200 amps except the meter enclosure then can you call that a 60 amp service? Not really because a 60 amp service would need to have a 60 amp OCPD not a 200.

In essence what you have is a 200 amp service with a violation of the incorrect size meter pan. With the exception of the meter enclosure burning up there is nothing to limit the current to 60 amps.

That’s definitely a factor when considering the size, and why I’m wondering where the idea to ignore the meter can in service size calculations came from.

I’m not sure either. As an electrical inspector I would look at the entire installation to see if it were code complaint and then determine the service size. If an element or several elements of the installation are not complaint then it’s rather difficult to say for sure what size the service actually is.

I know that HI’s have an SOP so I can live with that. :slight_smile:

That’s why I’m hoping Paul adds his wisdom. I’d almost bet we’re missing something simple here, but who knows.



You are correct. The meter base rightfully can be taken into account in the overall assessment but cannot be used as the basis for determining the service size. Likewise, the service drop conductors cannot be used as the basis for determining the service size.

This discounting of the meter is because of too many variables that can come into play then you (The HI) are determining the size of a service to report on a HI report.

My original response gives two options on how to address it.


Don’t look at it from an Electrical Inspectors perspective…you have to from the HI’s perspective to truly understand how to eliminate the less supporting component. In many cases the HI’s have very little data to go on and due to too many variables with meters it is best dismissed.

However, it can lead to confirmation when other factors need confirmation based on service entrance conductors (Overhead or Underground) are concerned (not service drops or service laterals ofcourse), panel enclosure ratings, main circuit breaker or fuse ratings and so on.

In fact, there was a time (sounds like a song) where the same 100A meter was also in some cases a 125A meter so it could get confusing. Now, as stated if you see something that looks like a 200 A service and a small square or round meter socket then REPORT IT…as that is obvious of work being done without a permit but again each inspection will be different and more so in the older homes these guys inspect.

Just my thoughts on it…Cheers

Thanks Paul, you definitely cleared some things up. If you’re ever up near San Antonio, let me know and we’ll grab lunch.


Greetings Mike,

If I am again down your way I will give you a hollar. If you ever get enough HI’s down that way who may be interested in an Electrical Defects Training just let me know. However, it would not be for HI CEU Credits as I am too lazy to submit for such credit to the State of Texas…:wink: