Confusing: do electrical wires run directly from the service panel to branch circuits?

I’m practicing to challenge my two proctored exams and find several of the questions confusing. I can easily confabulate answers to these questions but they just don’t make sense to me. For example, on this page:
Practice Questions - InterNACHI®

I found this question:

Really? It’s not like there’s anything separating the service panel from the branch circuit. I understand that the branch circuit includes the breaker which is in the service panel, but why would it be “wrong” to say “electrical wires run directly from the service panel to branch circuits?” Even if it’s not perfectly accurate? Am I missing something? Is there a reason this is just dead wrong to even think of it this way? Maybe someone got injured because they missunderstood this?

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IMO the question could be worded better to convey what they’re actually asking. Here’s the NEC definition of a branch circuit does this help?

Branch Circuit. The circuit conductors between the final overcurrent device protecting the circuit and the outlet(s).


Thank you for responding. I wish I could say that helps but I am not any closer to understanding why the answer to this question cannot be true. The way I see it, there is nothing between the panel and the branch circuit so I’d go with that and answer true.

All I can see from your comment is that the wires from the service panel are part of the branch circuits rather than connecting to them. Is that the reason it would be wrong to answer true?

Is it something else? Am I missing something? Can you try to break it down for me?

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The NEC likes to call the same thing by different names and the NHIE likes to confuse by vocabulary. I’m wondering if the TRUE statement would have to read: “Electrical wires generally run directly from the distribution panel to branch circuits.” The distribution and service panel can be the same thing but they don’t have to be. The “service” panel contains the main disconnect. The “distribution” panel contains the OCPDs for the various circuits.

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It’s a poorly written question but by definition the branch circuit begins at the OCPD. Between the OCPD and the service panel there are no electrical wires, the OCPD is connected directly to the bus of the panel.


Those are some ambiguous trial questions.
Ben, should be made aware of this.

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Terrible questions. Poorly written.

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There is no question but that electrical wires “run from,” or lead out of, the service panel to branch circuits. Intentional ambiguity in this instance is confirmed by the ridiculous answer.

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Doh, for crap sake, I never even thought of the distribution panel separately. I’ve worked with electricians on 40+ houses and they always called it the service panel. Obviously they were always combined. I remember the course explaining the difference but it just didn’t register to think of them separately.

I wish these questions came with links to NACHI content that explained the answers because I couldn’t find an explanation anywhere. Probably because I was thinking of them combined. There are dozens of questions that are just as baffling to me as this one. Maybe I’ll go track them down and start posting them all because you guys have been very helpful and I’d love to get explanations for all of them. I have just been memorizing the answers hoping the explanation would one day occur to me.

Yes, that is the explanation that sorted this out for me. Thank you.

You’re welcome. Often when questions are worded this way one has to try and think of what was in the person’s head when they wrote it. Having said that I’m not sure what the actual intent was probably something to do with the definition of branch circuit. :thinking:

If you have other questions post them too. There are many sharp people here who can try and help to decipher them.

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I guess the ambiguity in this instances served well to separate the laborer from the professional. If that was the objective then they succeeded.

Yes, many of the questions are so obvious they give you the answer, but many are so ambiguous you really have to know your stuff to figure out what the questioner was thinking. Like Smith said:

So, they can figure out how much, or little, I know with these kinds of questions.

Actually, David, such ambiguity is the mark of the amateur and enemy of the accuracy in technical writing inspectors should strive for.

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Important…words matter

I do not personally strive for technical writing. I strive accuracy and clear communication so the end user (my customer) can understand the problem in “laymen” terms.

Just my two cents. Your statement was insightful.

As already noted that is a horribly written question. And Nick is always complaining how the NHIE words their questions.

“The electrical wires” (conductors) Are the branch circuit.