A house I inspected yesterday - built in 1966. It had this Square D panel - with 2 breakers labelled “MAIN” each is labeled as “80” amps. These 2 MAIN breakers are independent of each other - I did something I was not supposed to - I threw the MAIN breakers. Each 1 cuts some of the power, and the 2 breakers do cut total power for the house. I’ve never seen this before - should these breakers be tied together? Is this a total of 160-amp service? Thanks!
Sounds like you were dealing with a split bus panel. Did you check the wiring diagram or internal panel wiring?
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Sounds like you encountered one of these: What is a split bus electric panel?
It’s not a 160 amp service. As mentioned by others it’s likely a split-bus panel. Do you have some photo’s? With a split bus panel the service size is usually indicated by the size of the service entrance conductors and/or the panel bus size.
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I’m still confused… it is obviously a split-bus panel. There are 2 main breakers which are labelled 80. Apparently, this is like having 2 80-amp services in the panel? Obviously, this panel should probably be replaced as it is likely original to this 1966 home.
No, that would make sense to actually check my pics before moving on…
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Eh…I feel ya. I just take pics of every damn thing because I have been burned. Photos are free and often have unforeseen value.
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I guess my main question is how do I report the service amperage? 2x80-amp?
I’ve done that in the past. Also, don’t be afraid to disclaim it as not clearly labeled. Our SOP allows that.
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Good advice - I’ve never used that, but it seems it is appropriate here. I’m going to refer to an electrician due to the age and design… Thanks!
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He has it right here 80 amp x2
My narrative. Main disconnect at panelboard consisted of two 80 amp breakers labeled “main”.
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I’m on board with that. I’ve used a similar description/terminology on past reports when it is not as simple as having a single main disconnect. I feel like the bottom line is that if it is not readily evident what the max amperage is, we don’t have to become super-sleuths. Honestly, very few clients are even looking at that info anyway, lol.
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I think you are referring it out because you are scared of it. Nothing wrong with the design that you can see other than you do not understand it wholly.
However, nothing wrong with recommending evaluation, service check-up or upgrade because of age.
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That’s not so obvious. Is the panel failing? Are there indications of heat damage? Poor workmanship? A history of failure for the brand or model? Lack of capacity? Anything wearing out, cracked? Are the wire sizes matched to the breakers? Double tap neutrals?
I’d get nowhere in my area recommending age replacement of such a panel. It’s not even old by local standards.
That panel may have the new owner’s lifetime, and more, left in it. There may be far higher priorities in the same home. There’s nothing inherently unsafe in that setup, and sometimes messing with something introduces new problems. You’ve got a setup that’s operated (apparently) correctly for 55 years. The new panel, who knows, the sparky may pinch one of the old wires and create a real hazard.
You are the neutral party: some percentage of electricians will give self serving answer and happily take the customer’s money for a new panel. Read up about split bus panels: or just look at the diagram. It’s pretty straightforward.
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It is definitely not a split bus panel. It’s a panel that is fed from two 80 amp main circuit breakers. Very old and strange design. A better photo of the label may provide a part number that you can use to gather more information.
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That’s why they have a home inspection done. An inspector ought to be able to do a proper assessment of an electrical panel.
Define proper assessment beyond a visual evaluation which is not technically exhaustive.
Example, I do not perform heat exchanger evaluations during my visual inspection. Should I not recommend one on an old furnace? Because I do. It is not a defect, it is a recommendation based on my experience. And yes, I will recommend this to be done by a qualified HVAC contractor, which I am not.
But I agree, yes an inspector should be able to assess an electrical panel visually and know what he is looking at as a “generalist” but not necessarily as a master electrician.
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