Need veteran assistance.

Currently working my way through the educational ranks of InterNACHi and I have a few questions on what’s written below directly out of the electrical inspection course. I sure would appreciate if a veteran home inspector could take a moment to help me better understand what’s going on here. I have a feeling I’ve been doing something wrong. Thank you for your time.

Calculating available amperage

In many cases the listing information about a home is incorrect about the service amperage, due to the broker or owner relying solely on the size of the main breaker or fuse. Many people are also mistakenly under the impression that the available amperage is the total of the individual breakers or fuses in the service panel.

The correct way to determine the available amperage is to determine the ampacity of the lowest rated of the following components:

  • Service supply
  • Electric meter & socket
  • Service entrance conductors
  • Service disconnect
  • Distribution panel
    Here are a couple of examples:
  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.
    *]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.
    A home inspector getting this wrong could potentially end up paying for a service upgrade costing several thousand $$$$$.

Hi Billy,

I wrote that course, what do you feel you are misunderstanding?

I tried to call you but I see from your website you are deployed overseas at this time. Thanks for your service. :smiley:



Mr. Beaumount,

Thank you for your time. I appreciate it very much. Do to that I’m currently in the middle east the best way to communciate is through instant messenger via I have an account set up for you. All you have to do is log on. Please send me a good email address to send this log on info to. Again I appreciate your time.


Hi Bill,

I have a Gmail account, I’ll pm you the address, I am heading out for the evening, but feel free to catch me most evenings.

Be safe


you da man Gerry …way to step up…

Just sent you a PM. Look foward to talking with you. Enjoy your evening Gerry.

Can you explain how this could possibly happen?

Hi Pete,

I can think of multiple senarios where a home inspector could overstate the service amperage.

For example, older home where the service drop, meter assembly, and panel feeders are 100 amp rated but the homeowner installed a panel with a 200amp main, many people would wrongly assume that as the main is 200 that that would be the rating despite the other rated components being smaller.



I get that, but how in the world could a H-I be liable to pay for an upgrade???

Hi Pete,

we get blamed for everything :wink:

Seriously though, if someone buys a home believing that they have service “X” and finds out that they have service “Y” who they going to blame??



It is really up to the PoCo to decide what meter they install. I bet if you called them and said you had a “60a” meter on a 200a service they would tell you there is nothing wrong with that.
I agree with you on all the user owned equipment. (disconnect, SE cable, panel etc.) but the PoCo does what it wants on their equipment.

Passed the course! :slight_smile:

Material was very well laid out and writer knowledge of subject was very apparent. Highly recommend this course be taught in HI schools nationwide. As a graduate of a certified 50 hr HI course in Oklahoma I can tell you first hand all students would benefit from having to take InterNACHI’s online courses within a classroom enviroment. It simply should become the norm.

Comment for InterNACHI education board: For future courses if it’s possible please provide feedback on the question’s missed on the final exams so they can be reviewed. Presently, a student simply either get’s a pass or fail score and you have no idea what was missed. Thank you!