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  1. #1
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    Default Main Disconnect(s) vs Main Service Panel

    In residential use, is or are the main disconnect or disconnects always located in the main service panel? That's what I normally see, but I don't know if it's a code requirement or not. If it is a requirement, can someone cite the code for me? I appreciate the help with this.
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    Mike Chambers
    BrickKicker Home Inspections

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  2. #2
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    Default Re: Main Disconnect(s) vs Main Service Panel

    The main disconnect for a service is not always in the "main service panel". It could be a fused disconnect or an enclosed circuit breaker. Either way the disconnecting means needs to be nearest the point of entry of the service conductors.

    2008 NEC Article 230.70 (A) (1)
    The service disconnecting means shall be installed at a readily accessible location either outside of a building or structure or inside nearest the point of entrance of the service conductors.


  3. #3
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    Default Re: Main Disconnect(s) vs Main Service Panel

    Thanks Ken for the quick answer!

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    Mike Chambers
    BrickKicker Home Inspections


  4. #4
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    Default Re: Main Disconnect(s) vs Main Service Panel

    Quote Originally Posted by Michael Chambers View Post
    In residential use, is or are the main disconnect or disconnects always located in the main service panel? That's what I normally see, but I don't know if it's a code requirement or not. If it is a requirement, can someone cite the code for me? I appreciate the help with this.
    _______________
    Mike Chambers
    BrickKicker Home Inspections

    Mike,

    The "main disconnect" *IS* *ALWAYS* located at the main "SERVICE panel" as that is what makes it a "service panel".

    If the main disconnect was not located there, it would not be "service equipment" and would therefore *not be* a "service panel".

    I realize this is the opposite of what Ken stated, however, when you understand that the "service equipment" *IS* where the "service disconnect" is located (the "main disconnect" and "service disconnect" are one and the same), then you will immediately understand that to be a service panel it must therefore also be part of the service equipment ... otherwise it is simply a "panel".

    Jerry Peck, Construction / Litigation Consultant
    Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
    www.AskCodeMan.com

  5. #5
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    Default Re: Main Disconnect(s) vs Main Service Panel

    So, a fused disconnect or an enclosed breaker, examples cited by Ken, would be the main service panel because of the presence of a main disconnect. And, as I understand it, this is also where the common buss would be bonded, bringing the commons together with the ground circuit.

    The large panel right next to it (or somewhere else for that matter) that is full of breakers that are distributing power throughout the house, and is being fed by a simple fused disconnect main service panel, is simply a distribution panel. It also would not be bonded, and the commons would be floating.

    Ken was making the point that the main disconnect is not always in the distribution panel, and it appears that you agree with that.

    If all this is correct, then I understand it. I needed the distinction you've made that the presence of the main disconnect is what makes that piece of service equipment the main service panel. Thank you for your help!


  6. #6
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    Default Re: Main Disconnect(s) vs Main Service Panel

    Quote Originally Posted by Michael Chambers View Post
    So, a fused disconnect or an enclosed breaker, examples cited by Ken, would be the main service panel because of the presence of a main disconnect. And, as I understand it, this is also where the common buss would be bonded, bringing the commons together with the ground circuit.
    Correct. Whether fused or unfused (which simply means "protected or unprotected") as part of the disconnect, and, if not part of the disconnect, then the overcurrent protection would need to be in or immediately adjacent to, the disconnect.

    Let's take the normal "typical" installation where the disconnect is fused (protected by either a fuse or a breaker).

    The large panel right next to it (or somewhere else for that matter) that is full of breakers that are distributing power throughout the house, and is being fed by a simple fused disconnect main service panel, is simply a distribution panel. It also would not be bonded, and the commons would be floating.
    Correct. Even if it was immediately adjacent thereto and connected with a closed nipple, as close as you could get. It would still be "separate" from the service equipment and would simply be a panel with the neutral isolated from ground.

    Ken was making the point that the main disconnect is not always in the distribution panel, and it appears that you agree with that.
    That was one point Ken was making, and on that point I agree with Ken.

    If all this is correct, then I understand it. I needed the distinction you've made that the presence of the main disconnect is what makes that piece of service equipment the main service panel.

    The presence of the service disconnect "in the same enclosure" with the panel or "not in the same enclosure" with the panel. Yes, that is what makes the difference. Just clarifying that point.

    Jerry Peck, Construction / Litigation Consultant
    Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
    www.AskCodeMan.com

  7. #7
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    Default Re: Main Disconnect(s) vs Main Service Panel

    The service disconnect is required to be labeled as a "service disconnect". Main breakers are just that, the main breaker for a panel. If the panel happens to be service equipment then that breaker gets labeled as a "service disconnect". If the breaker isn't a service disconnect it gets labeled as a main breaker. Panels, well load centers anyway, come with labels to mark the breaker appropriately. A stand alone breaker or switch used as a service disconnect must be marked as such. Either of these used to disconnect non-service equipment should be marked as to what they disconnect. The NEC only makes one reference to a main breaker and it is in conjunction with specialized wiring

    In every jurisdiction I'm aware of, the NEC blurb [230.70(B)]that says a service disconnect shall be identified as a service disconnect means that it is labeled "SERVICE DISCONNECT". Marking the service disconnect as a "MAIN", "MAIN DISCONNECT, or anything but "SERVICE DISCONNECT' will result in a correction notice.


  8. #8
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    Default Re: Main Disconnect(s) vs Main Service Panel

    Quote Originally Posted by Bill Kriegh View Post
    The service disconnect is required to be labeled as a "service disconnect".
    We have been through this before and it does not require being marked or labeled "service disconnect", only that it be marked to identify it "as a service disconnect", and marking or labeling it "Main", "Service Main", "Main Disconnect", etc., indicating that is where the service is disconnected is what is required.

    In every jurisdiction I'm aware of, the NEC blurb [230.70(B)]that says a service disconnect shall be identified as a service disconnect means that it is labeled "SERVICE DISCONNECT". Marking the service disconnect as a "MAIN", "MAIN DISCONNECT, or anything but "SERVICE DISCONNECT' will result in a correction notice.
    Likewise, in the AHJ that I am familiar with, does NOT require the wording "Service Disconnect", only that the service disconnect be marked to let everyone know that it is the main source of disconnecting the service, i.e., "Main", "Main Disconnect", etc.

    Thus I guess it depends on the AHJ in the area.

    At least until clarification is made in the code to address it as .... "shall be marked and labeled with the words Service Disconnect. When, and if, the code ever says that, then the issue will be resolved".

    The code DOES specifically require specific wording on some things, and when it does, it SPECIFICALLY states so, here is an example:
    - Thermally Protected (as applied to motors). The words Thermally Protected appearing on the nameplate of a motor or motor-compressor indicate that the motor is provided with a thermal protector.

    Jerry Peck, Construction / Litigation Consultant
    Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
    www.AskCodeMan.com

  9. #9
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    Default Re: Main Disconnect(s) vs Main Service Panel

    Perhaps it would be a good idea to respond accordingly then. There isn't a hard fast rule across jurisdictions. The "service disconnect" label is required statewide in Colorado as far as I'm aware. We have state inspectors as well as city and county inspectors where the entity is large enough to support them.

    Most panels have "main" stamped into the metal adjacent to the breaker location. When used as a service equipment, panels lacking the service disconnect label get written up, an indication that to these folks the "main" designation isn't sufficient to indicate a service disconnect.

    Last edited by Bill Kriegh; 06-11-2009 at 09:23 PM.

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