Beam me up Scotty

We have a problem house built in 2008 in the country no AHJ inspection total electrical 5 ton heat pump with 4 15 KW strip heat, 2 electrical cook stoves remote cook top 2 whirlpool tubs a private well for water and Aerobic septic system 3 bathroom exhaust fans with electric heaters and one 50 gallon electrical water heater.
My write up was a little different than what was on the Realtor sheet.

The main panel was 200 amp and had a 100 amp sub feeding the additional panel side by side. As you can see I exceeded the 80% a bit.

I find this a lot but always on a home that has been added on to one or more times and the electrical was not updated. This was my first for a new home the electricians were so proud of their work they signed and dated the inside of the panel. 218 amps sure makes for nice thermal images

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Wow. How did you manage to get the 218 amp reading, did you turn everything on at once? Looks like the service is too small. I wonder what a load calculation would say about the connected load.

I was wondering the same thing.

Charley, did you turn everything on to see that load.?
I think they need a bigger panel Eh!:slight_smile:

Nice work. I am just starting toread more and understand electrical systems in the residential home.
Good work.

Good morning Robert and Ole Charley knows his thingy. :mrgreen::wink:

Are there neutrals going to the ground buss in the subpanel?

They are all puting there stickers on the panels. Yes they do make mistakes because business pushes them to the limit. I always have to laugh when I watch “Mike Homes and his teem” rip out and gut the whole basement just because they found something wrong with the panel. He would have fun here. I have found so many wrong problems with new reno’s I am just about to explode.

I always use the inhouse appliances and what ever else is available to get a load as I scan thermally all electrical panels. This house just happen to be total electrical got 218 amps without the dishwasher or a dryer the home was vacant


Sorry I answered to quick yes there were neutrals on the ground buss in the sub but not in the main

Thanks for the correction. I thought I saw two that are just above the top breakers on the left side. One looks like it comes from the yellow NM with the long sheath at the bottom of the panel.

Hey Charley,

“218 amps sure makes for nice thermal images”!

Do you have any thermal images of this to show us?

Thank you!

Brossard, Quebec, Canada

Morning to you to Marcel. Well afternoon now.
Yes it is very interesting. I find it a help to follow this electrical system chatter.
HVAC AND ELECTRICAL. That’s my week areas.

Yes I have will post them later have a report to get out

So the question is, is the panel a violation or not with a load of 218 amps?

While that might be handy to help with an IR scan due to the non-typical usage, it does not represent how the service will typically be used or if it is too small. Kind of like adding up all the breaker handle ratings and saying the service is too small.

My understanding and what I have always gone by is its not allowed to exceed 80% of the rating of the panel period. I load the panels up with what is available knowing perfectly well that it would be very unusual for every appliance in the home to be on at the same time but that should make no difference if the appliance are installed the rating of the panel should allow for them all to be on at the same time. Here are a couple images of the panel before I shut the test down once I saw 218 amps the 200 amp main had got up to 115 degrees before I shut down don’t know how high it would have got to If had not shut down when I did

Shouldn’t this cause the main breaker to trip.

Eventually it will, maybe. That’s likely an inverse-time CB which will trip faster based on a larger amount of overload. More overload faster trip. This is based on the manufactures trip curve. For a 10% overload it may take hours to trip.

Would that be sufficient to protect circuits from overheating? Or normally would individual circuit breakers trip first, or easier?