An electrician added a new circuit to our panel today. It was simple, a 20A dedicated circuit to power a treadmill. He labelled the new breaker on the door of the panel:

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What does the circle with two slashes indicate? I see it on a few other circuits as well.

  • 1
    Specifically, this is the symbol commonly used on architectural drawings to denote a duplex outlet (two sockets). You may also see similar symbols for single-socket outlets (circle with one vertical line) or for quad outlets (circle with two vertical and two horizontal lines, like a # symbol). The symbols are more useful for the single/quad outlet cases since those are less common and the extra information can make it easier to locate the outlet in question.
    – bta
    Apr 18, 2023 at 17:11

2 Answers 2


It means the circuit terminates in an outlet. That outlet used for the treadmill

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    And ... that notation will confuse another person who owns the house or works on the panel, who has no idea where the treadmill was or which outlet it was plugged into. It's much better to identify an outlet by room ("SW 20x30", "Kitchen" etc.) and wall ("N").
    – Wastrel
    Apr 18, 2023 at 14:17
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    I see that, @Wastrel. But considering how heavy the thing is I think it will be there for some time to come :)
    – nuggethead
    Apr 18, 2023 at 17:50
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    @Wastrel that's how I ended up with breakers at my last house named 'freezer', 'computer room', and 'office'. Finally had to give up and get one of those breaker locators.
    – KMJ
    Apr 18, 2023 at 18:15
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    Look on the bright side, at least it doesn't say "new outlet" (because it stays "new" forever of course). Apr 18, 2023 at 22:10
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    @Wastrel I don't think I have ever owned a house where the breaker circuits were labelled in an understandable manner. One of the first things I always wind up doing when buying a new house is to create a schematic mapping every last outlet, switch, light, etc. to which breaker controls it. It makes a nice parting gift when selling as well...
    – Michael
    Apr 19, 2023 at 18:59

In blueprints it marks an outlet. I suppose on a panel it marks that there is an outlet on the circuit? Not too useful.

What's important is the 1st-grade penmanship. I believe that's mandatory on panels.

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    I'll take credit for the penmanship. I drew it here with a mouse
    – nuggethead
    Apr 18, 2023 at 1:09
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    Also, in fairness, many times labels are being written directly on the panel, which isn't flat.
    – Huesmann
    Apr 18, 2023 at 13:40
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    Do you ever have a moment where you wish you took a picture of every panel door in every place you lived in your life? Ok probably not ... but I'm having that now. :)
    – jay613
    Apr 18, 2023 at 14:29
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    There's always a label maker, and for installs older than 3 decades, Dymo tape. It's an issue of extra effort.
    – user71659
    Apr 18, 2023 at 22:42
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    @user71659 There is no "always" for any item, no matter how important it is.
    – MikeB
    Apr 19, 2023 at 6:29

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