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  1. #1
    Roger Frazee's Avatar
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    Default 6 disconnect rule for detached residential garage

    Was it ever a correct installation (code wise) to apply the 6 disconnect rule to a panel in a residential detached garage fed with a feeder from the service equipment panel at the home/dwelling ?

    Seems I'm told on another forum if in the days of LA&BCPs and power panels it wouldn't be possible to meet service rated requirements for the disconnect as it would almost certainly be a lighting and appliance branch circuit panel board.

    We have for as long as I can remember while working (up to 2007) ... we were allowed to use the six disconnect rule and install an MLO panel as long as we did not exceed the 6 disconnects.. now that it has been brought to my intention it appears we were in violation of the written code....?

    Only bring this up on this forum as it may be related to an HI inspection where they are possibly approving a non compliant panel.

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    Default Re: 6 disconnect rule for detached residential garage

    RF, plz decode ur abbrvtns.
    LA&BCPs MLO


    Jim Luttrall
    www.MrInspector.net
    Plano, Texas

  3. #3
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    Default Re: 6 disconnect rule for detached residential garage

    Quote Originally Posted by Jim Luttrall View Post
    RF, plz decode ur abbrvtns.
    LA&BCPs MLO
    L&ABCP = Lighting and Appliance Branch Circuit Panelboard

    MLO = Main Lug Only ... no single throw main breaker in the panel nor a back fed main

    Sorry




  4. #4
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    Default Re: 6 disconnect rule for detached residential garage

    If it takes six or less hand movements to kill all of the power leaving the service panel it is ok in my book. It does not matter what the panel is feeding. IMHO


  5. #5
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    Default Re: 6 disconnect rule for detached residential garage

    Quote Originally Posted by James Duffin View Post
    If it takes six or less hand movements to kill all of the power leaving the service panel it is ok in my book. It does not matter what the panel is feeding. IMHO
    It appears that several municipalities still allow the 6 disconnect rule for panels in detached buildings on residential property.


    It appears and I have verified this that the panel will state on its labeling that it is service rated as long as it is not used as an L&ABCP. It would be dang near impossible IMO for a panel to not be LA&BCP in a residential garage.


  6. #6
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    Default Re: 6 disconnect rule for detached residential garage

    I think I am lost....are you saying that the panel in the garage is considered a service but is being fed from the service on the house.


  7. #7
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    Default Re: 6 disconnect rule for detached residential garage

    The NEC requires a disconnect for the detached building. It must to be suitable for service equipment (service rated) as outlined in article 225. In order for a mlo panel (residential load center) to be service rated proir to 2008 it must not be used for a LA&BCP under the 6 disconnect rule.. In 2008 they did away with the power panel and LA&BCP and now the panel must have a single throw main breaker installed to be service rated.... at least that is how I'm now understanding.

    Last edited by Roger Frazee; 09-23-2010 at 08:12 PM.

  8. #8
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    Default Re: 6 disconnect rule for detached residential garage

    Quote Originally Posted by Roger Frazee View Post
    The NEC requires a disconnect for the detached building. It must to be suitable for service equipment (service rated) as outlined in article 225. In order for a panel (residential load center) to be service rated proir to 2008 it must not be used for a LA&BCP. In 2008 they did away with the power panel and LA&BCP and now the panel must have a single throw main breaker installed to be service rated.... at least that is how I'm now understanding.

    Thanks for the clarification. Here is what I see in the 2005 and 2008 codes about the disconnects.

    225.36 Suitable for Service Equipment.
    The disconnecting
    means specified in 225.31 shall be suitable for use as
    service equipment.

    Exception: For garages and outbuildings on residential
    property, a snap switch or a set of 3-way or 4-way snap
    switches shall be permitted as the disconnecting means.



  9. #9
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    Default Re: 6 disconnect rule for detached residential garage

    If fed from the service panel in the home, this is detached structure, feeder circuit, limit has been no more than two devices protecting feed side and disconnect side at the detached structure for a long while.

    Once past the disconnect (maximium two devices, two fuses one for each "leg" one block, etc.) at the detached structure then you can have six on a load side panel, or use suitable equipment that incorporates both functions (panel with main).


  10. #10
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    Default Re: 6 disconnect rule for detached residential garage

    Quote Originally Posted by H.G. Watson, Sr. View Post
    If fed from the service panel in the home, this is detached structure, feeder circuit, limit has been no more than two devices protecting feed side and disconnect side at the detached structure for a long while.

    Once past the disconnect (maximium two devices, two fuses one for each "leg" one block, etc.) at the detached structure then you can have six on a load side panel, or use suitable equipment that incorporates both functions (panel with main).
    Ok that makes sense. Then it would appear we were in violation of written code using an mlo as the disconnect without a service rated disconnect ahead of that panel near the entrance of the feeder to the detached structure.

    As an example while I was trying to get this figured out I came across this guideline and some others that basically said the same thing.

    Look at ( 2.) on ' rules to operate by' would this not be a violation if I am understanding correctly...

    speaking about where they say a panel with 6 breakers or less will satisfy the disconnect for the building.

    http://www.ci.bloomington.mn.us/hand...3fffdetach.pdf


  11. #11
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    Default Re: 6 disconnect rule for detached residential garage

    It looks like it depends on what size feeder you have going to the garage. If the circuit is not over the rating of the switch you can use a snap switch for the disconnect. I have never seem a snap switch rated over 30 amps but there may be one.


  12. #12
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    Default Re: 6 disconnect rule for detached residential garage

    Quote Originally Posted by Roger Frazee View Post
    Was it ever a correct installation (code wise) to apply the 6 disconnect rule to a panel in a residential detached garage fed with a feeder from the service equipment panel at the home/dwelling ?

    Roger,

    Are you referring to feeder taps?

    Or are you referring to where the feeders are supplied by a breaker (or fuse) at the service equipment?

    Almost sounds like you are referring to a second service equipment installation which is not grouped with the first service equipment?

    Or are you referring to this?
    - ARTICLE 225 Outside Branch Circuits and Feeders
    - - II. More Than One Building or Other Structure
    - - - 225.33 Maximum Number of Disconnects.
    - - - - (A) General. The disconnecting means for each supply permitted by 225.30 shall consist of not more than six switches or six circuit breakers mounted in a single enclosure, in a group of separate enclosures, or in or on a switchboard. There shall be no more than six disconnects per supply grouped in any one location.
    - - - - - Exception: For the purposes of this section, disconnecting means used solely for the control circuit of the ground-fault protection system, or the control circuit of the power-operated supply disconnecting means, installed as part of the listed equipment, shall not be considered a supply disconnecting means.
    - - - - (B) Single-Pole Units. Two or three single-pole switches or breakers capable of individual operation shall be permitted on multiwire circuits, one pole for each ungrounded conductor, as one multipole disconnect, provided they are equipped with identified handle ties or a master handle to disconnect all ungrounded conductors with no more than six operations of the hand.

    Jerry Peck, Construction / Litigation Consultant
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  13. #13
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    Default Re: 6 disconnect rule for detached residential garage

    Sorry I wasn't able to get back this evening till now. Let me try to be more clear by example.

    I build a detached garage next to my home. I decide to install a panel in that garage and supply power to that panel from the service equipment in the home. I decide to run a 100 amp feeder underground in pvc pipe to the garage and install a 100 amp breaker in my homes service equipment to protect that feeder to the garage.

    I must provide a service rated disconnect at the detached garage nearest the point of entrance of the feeder. I decide to use a 100 amp 20 circuit mlo panel with 5 single pole breakers in it to operate lights and receptacles with thoughts of adding circuits in the future that would power some woodworking tools.

    But for the time being just the 5 single pole breakers in that 20 circuit panel. So I mount the panel in the garage and land my feeder directly to the main lugs of that panel.

    Does this satisfy the disconnect requirement of 225.36 ?

    The labeling on modern panels states that the panel is ...
    suitable for use as service equipment with 6 disconnects or less and the panel is not used as a lighting and appliance branch circuit panelboard.
    Now this is before the 2008 code changes on panelboards as now a main would be required in the panel.

    I was shown several mlo panels from different manufacturers with labeling to that effect. I am told that I would be in violation of the nec using that mlo panel as a lighting and appliance branch circuit panelboard without a main breaker. It will not satisfy the 'service rating' for the disconnect of that detached garage due to the label listing.

    If this is so and all load centers that are mlo have this labeling prior to 2008 (and I'm told they do) then it would be a violation to use one under the 6 disconnect ruling as it would be darn near impossible for it to be used for anything other than a LA&BCP in a residential detached garage.

    I made a drawing (below) to make this more clear ... it illustrates an installation to NEC 2008.

    Think in terms of prior to 2008 when there were LA&BCP and Power Panels ..

    Now looking at the drawing below if I take away the main breaker in that detached building panel and make the panel mlo with 5 single pole 20 amp circuit breakers installed for branch circuits to lights and receptacles will this satisfy the service rated disconnect required for the detached building under the 6 disconnect ruling ??

    I am told no it will not because of the panel listing and labeling as mentioned earlier. I am also told all mlo load centers at least prior to 2008 manufacturers dates for residential have this labeling. I've looked at 5 or 6 and they do have that labeling.

    I'm not sure how far back you would need to go before that labeling would not be present.

    See item 23 page 14 of this document to see the example wording/labeling for service rating for an mlo panel
    http://www.ul.com/global/documents/o...2006_Final.pdf

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    Last edited by Roger Frazee; 09-22-2010 at 12:12 AM.

  14. #14
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    Default Re: 6 disconnect rule for detached residential garage

    Roger, I could be wrong, but in your example you have a properly rated over-current protection device at the service equipment on the house so a secondary disconnect would not be needed at the remote panel.

    If you did not have a breaker up stream then you would need to worry about your scenario as well as other issues.

    Let the NEC experts begin.

    Jim Luttrall
    www.MrInspector.net
    Plano, Texas

  15. #15
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    Default Re: 6 disconnect rule for detached residential garage

    Hi Jim

    I am understanding the NEC to require a service rated disconnect located at the nearest point of entrance of the feeder to the detached garage.

    Also added a link to the ul panelboard marking guidelines in the last post I made.


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    Default Re: 6 disconnect rule for detached residential garage

    A service rated disconnect at the remote detached structure is not required if the limitations for the exception were met for one residential branch circuit to the remote structure from the residence panel protected by OCPD at the circuit origin, but a disconnect at the garage entrance is required (just not required to be "service equipment rated"). IIRC 30A used to be the limit.

    A 2-pole switch or pull-out box can suffice at the garage entrance.

    For the purposes of that Exception, a (one) MWBC is considered single circuit as long as it is protected at its (the circuit's) origin by one single 2-pole 120/240 device (same molded case even if two switch handles or two fuses pull-out) not two individual 125v single pole breakers with handle ties or similar.

    Not a tap. A tap would require service rated disconnect and OCPD to protect the tap conductors at the garage entrance, as there would be no disconnect or protection sized for just the tap conductors at the tap.

    From what I'm gathering in your question Roger, you are asking about a single "feeder" Circuit protected by a properly rated OCPD secondary disconnect at its (the circuit's) origin, load side of the primary "service rated" disconnect and the main service OCPD for the service entrance itself, WITHIN the residence; not a "feeder" tap (no secondary OCPD or disconnect at its "origin").

    Last edited by H.G. Watson, Sr.; 09-22-2010 at 11:22 AM.

  17. #17
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    Default Re: 6 disconnect rule for detached residential garage

    Good afternoon HG thanks for responding

    In the diagram if I run a 4 wire feeder or 3 wire feeder to the panel in the detached building and protect that feeder with a ocpd in the service equipment of the home can the panel in the detached garage be mlo with 5 single pole breakers serving as the required service rated disconnect for the detached building? This would be using the 6 disconnect ruling.

    Is that code compliant?

    I'm told no because the panel is LA&BCP and therefore must have a single throw main breaker to comply with the labeling (mentioned earlier) for compliance with a service rating.. NEC 225.36 says the building disconnect must be service rated. The Panel labeling states that if your going to use 6 disconnects or less then it will be a service rated disconnect as long as you do not use it as LA&BCP. If you use it as L&ABCP it will not be service rated and you cannot use it as the service rated disconnect under the 6 disconnect ruling.. The mlo panels seems to be labeled this way.

    Very confusing but that is what the labeling on the panel states and so far every mlo I have looked at has that labeling..

    Last edited by Roger Frazee; 09-22-2010 at 11:49 AM.

  18. #18
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    Default Re: 6 disconnect rule for detached residential garage

    Just so everyone knows I'll be offline for the next 4 or 5 hours be back around 7:00 central time.


  19. #19
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    Default Re: 6 disconnect rule for detached residential garage

    If you have a disconnect line side entrance to garage - does not have to be service rated, but has to be sufficiently rated for the feeder circuit itself, this is NOT a feeder tap, ahead or line side of your MLO Lighting and appliance circuit panel board and any other outlet. IF you meet the rules for the residential single circuit exception to remote structure and a single feeder branch circuit MWBC can meet that exception which includes NO other metallic paths between the two structures and eliminates the possiblity of a remote 3-way switch circuit now with grounding and bonding requirements.

    Local bonding for the equipment and building is also necessary with introduction of a panel - usually 2 driven rods, or one plus the UFER if present. The use of the detached structure has to be of a residential nature - not ag, business, professional garage repair business, commercial venture, etc. Put a pull out disconnect or a double pole switch depending on if you're running a 30 or 20A MWBC. Most pull-out disconnects are rated up to 65A IIRC.Now, where are you at and what are the rules where you are at? Some local jurisdictions require a disconnect on the exterior of every structure including residences and their accessory structures. Some locales modify the multitude of articles which apply. Some further modify. Don't know what edition or ammendments rule in your application.Can and May....not going there.

    You seem to be asking in present for future now, thought this started out about past.

    1999 is where things were being mopped up from the earlier 80s and early 90s debacles.

    Read though this review article about chages in the 1999 NEC, might answer some of your questions as you review it.

    Illustrated Changes in the 1999 NEC — Part 1 of 4

    As you review the article you may find some "bells" going off in the ol' noggin regards to endless debates prior what is a power feeder, can you tap a tap, what IS a tap, etc. and what disconnect ratings are, etc.

    As you review the summary article I linked to above (clickable link to EC&M) the original question and your discussions elsewhere with others (don't know where, or what was said, just how you seemed to characterized it which, I find some fault with, esp. how equipment was listed) may make more sense.

    HTH, as you revisit your past experience or not.

    Last edited by H.G. Watson, Sr.; 09-22-2010 at 04:33 PM.

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    Default Re: 6 disconnect rule for detached residential garage

    Quote Originally Posted by Roger Frazee View Post
    But for the time being just the 5 single pole breakers in that 20 circuit panel. So I mount the panel in the garage and land my feeder directly to the main lugs of that panel.

    Does this satisfy the disconnect requirement of 225.36 ?
    No.

    Not as described.

    You could, however, install a maximum 4 or 6 breaker panel and that would satisfy the disconnect requirements of 225.33 and of 225.36 if labeled as suitable for service equipment. I find the requirement of 225.36 strange as: 1) it cannot be installed as service equipment; 2) the disconnecting means is allowed to be snap switches or 3-way or 4-way switches. Now, if the code said "may" be suitable for use as service equipment, then I could agree with that.

    Jerry Peck, Construction / Litigation Consultant
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  21. #21
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    Default Re: 6 disconnect rule for detached residential garage

    Thanks HG for that link. I just got in so have not reviewed as yet.

    I'll rephrase my question and see if that helps. ... And I'm talking about an installation under 2005 NEC or before ...residential]

    If I install a 100 amp mlo panel in a detached garage and install only 5 single pole breakers in that panel ( it's a 20 circuit panel) to supply lights and receptacles and protect the feeder to that panel with a 100 amp double pole breaker in the single family dwellings service equipment ... will the 100 amp mlo panel with the 5 single pole circuits breakers pass muster as the detached building disconnect under the 6 disconnect ruling ?

    I am being told no .. because the mlo panels for residential load centers are listed to only be service rated under the 6 disconnect rule if the panel is not used as a LA&BCP.
    I never installed a panel in a residential detached garage that was not LA&BCP ...

    The catch here is the 'service rating' or suitable for service equipment labeling in the mlo panel.

    My understanding is that 225.31 requires a disconnect for the feeder and 225.32 requires that disconnect to be located at the nearest point of entrance of the feeder inside or outside the detached garage ... the breaker in the service equipment will not satisfy the detached building disconnect requirement. 225.36 requires the disconnect in 225.31 to be service rated.

    225.33 allows that disconnect to be in the form of six circuit breakers or less under the 6 disconnect ruling.

    Which brings us back to the mlo panel labeling saying that the mlo panel is service rated under the 6 disconnect ruling if it is not used as a LA&BCP. My understanding is that all mlo panels for residential have this listing on the panel specifications sheet.

    I'm trying to locate an actual mlo panel labeling online to show what I am talking about.

    When I was working we installed many 100 amp panels as I described that passed inspection for the building disconnect under the 6 disconnect ruling and as mentioned in the guideline for Bloomington, Minnesota in the beginning of this thread. It seems though that the building disconnect must be service rated for a 60 amp, 100 amp feeder etc...

    In summary the position the person I am in discussion with says that an mlo panel will not comply as the required service rated detached building disconnect for the 100 amp feeder due to its listing. Because to be service rated under the 6 disconnect rule it cannot be used as a LA&BCP .

    In 2008 this became a mute point as the panel will now require a main breaker.


  22. #22
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    Default Re: 6 disconnect rule for detached residential garage

    Quote Originally Posted by Jerry Peck View Post
    No.

    Not as described.

    You could, however, install a maximum 4 or 6 breaker panel and that would satisfy the disconnect requirements of 225.33 and of 225.36 if labeled as suitable for service equipment. I find the requirement of 225.36 strange as: 1) it cannot be installed as service equipment; 2) the disconnecting means is allowed to be snap switches or 3-way or 4-way switches. Now, if the code said "may" be suitable for use as service equipment, then I could agree with that.
    Thanks Jerry

    Your addressing what I've been trying to ask. This is strange to me also ... this service rating requirement.

    Ok I think I understand about the 4 or 6 breaker panel as it would not allow more than 6 disconnects. Is that where your going?

    Back in an hour my neighbor is bar - b - que-ing tonight ....

    Last edited by Roger Frazee; 09-22-2010 at 07:45 PM. Reason: correct spelling

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    Default Re: 6 disconnect rule for detached residential garage

    Quote Originally Posted by Roger Frazee View Post
    Ok I think I understand about the 4 or 6 breaker panel as it would not allow more than 6 disconnects. It that where your going?

    Yes, that is where this train is going, and in fact that is the next stop ... I should qualify that 'Yes' with 'as long as it is a CTL panel' - it would need some way of rejecting half-size breakers, otherwise the 6 disconnect/overcurrent device maximum could be defeated.

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  24. #24
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    Default Re: 6 disconnect rule for detached residential garage

    Quote Originally Posted by Jerry Peck View Post
    Yes, that is where this train is going, and in fact that is the next stop ... I should qualify that 'Yes' with 'as long as it is a CTL panel' - it would need some way of rejecting half-size breakers, otherwise the 6 disconnect/overcurrent device maximum could be defeated.
    Yes I was just thinking the same thing while I was off eating some ribs....

    Jerry

    I haven't been successful ( not yet anyway) finding an online label listing for a mlo panel to show the labeling I've been discussing. If you had the chance did you look at that link ( post 13) to the UL markings for panels and the page I referenced. That seems to substantiate the labeling for some mlo ctl panels. And it has the wording that will be listed on the panel label in that paragraph... (23)

    Also somewhere close to that paragraph it talks about if a panel uses the 6 disconnect rule that even though you may be able to exceed 6 disconnects with some combination of breakers there must be at least one combination that is exactly six disconnects and
    uses all the spaces in the panel.

    This was something I never knew ...

    Last edited by Roger Frazee; 09-22-2010 at 08:58 PM.

  25. #25
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    Default Re: 6 disconnect rule for detached residential garage

    Quote Originally Posted by Roger Frazee View Post

    In 2008 this became a mute point as the panel will now require a main breaker.
    Where did you find this in the 2008 code?


  26. #26
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    Default Re: 6 disconnect rule for detached residential garage

    Quote Originally Posted by James Duffin View Post
    Where did you find this in the 2008 code?
    Start with 408.30 then go to 408.36 ...if you cannot meet the exceptions of 408.36 the panel now requires a main breaker. This is all about the dropping of the LA&BCP and POWER Panel classifications and the removal of the 42 circuit limit for panelboards.


  27. #27
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    Default Re: 6 disconnect rule for detached residential garage

    408.36 Overcurrent Protection.
    In addition to the requirement
    of 408.30, a panelboard shall be protected by an
    overcurrent protective device having a rating not greater
    than that of the panelboard. This overcurrent protective device
    shall be located within or at any point on the supply

    side of the panelboard.

    To me...it looks like based on 408.36 the breaker in the panel feeding the remote panel meets the code requirement.



  28. #28
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    Default Re: 6 disconnect rule for detached residential garage

    Quote Originally Posted by James Duffin View Post
    408.36 Overcurrent Protection.
    In addition to the requirement
    of 408.30, a panelboard shall be protected by an
    overcurrent protective device having a rating not greater
    than that of the panelboard. This overcurrent protective device
    shall be located within or at any point on the supply

    side of the panelboard.

    To me...it looks like based on 408.36 the breaker in the panel feeding the remote panel meets the code requirement.
    The problem with that is the detached building must have a 'service rated' disconnect located at the building . 408.36 'general' works if the panelboard is located in the same structure or dwelling as the service equipment where you can group the mains or one main can remove power for both the service equipment and the remote panel in that same structure/building/dwelling.

    In this case we are discussing I cannot meet a 'service rated' disconnect if I want to use a mlo 100 amp 20 circuit panel in the detached garage as the building disconnect without a main breaker in it. As Jerry said the mlo panel cannot except more than 6 disconnects and it must be CTL. If I have a panel like that and the labeling/listing allows me to use 6 disconnects and it is service rated in the manner I want to use it then I can meet service rated for the disconnect located at the detached garage.

    So to allow 408.36 first paragraph I must meet one of the 3 exceptions of 408.36. BUT I have a panel in a detached building remote from the service equipment and I have to comply with article 225 also.

    Exception 2 .. would apply to a remote panel in the same structure as the service equipment that cannot hold more than 42 circuits (CTL) (NEC 2008)

    Exception 1 .. won't apply to the detached garage 100 amp panel because it is not 'service equipment' yet it must be service rated ... to be used as the building disconnect ...... kinda hard to figure that one out in my opinion.

    And exception 3 obviously does not apply.

    It's all rather confusing and maybe someone else here can explain it in better than I.

    Last edited by Roger Frazee; 09-23-2010 at 08:14 PM. Reason: added CTL

  29. #29
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    Default Re: 6 disconnect rule for detached residential garage

    Thanks for taking the time to type all that out! I don;t agree 100% but that's ok too!


  30. #30
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    Default Re: 6 disconnect rule for detached residential garage

    Quote Originally Posted by James Duffin View Post
    Thanks for taking the time to type all that out! I don;t agree 100% but that's ok too!
    Hey I don't agree either... I'm just trying to sort out the code language and how it would or would not support a 100 amp 20 circuit mlo in the detached building with 6 disconnects or less installed in it. A rather experienced electrician told me it was not compliant as the building disconnect and that caused me to go ....


    Roger


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    Default Re: 6 disconnect rule for detached residential garage

    Quote Originally Posted by Roger Frazee View Post
    If you had the chance did you look at that link ( post 13) to the UL markings for panels and the page I referenced. That seems to substantiate the labeling for some mlo ctl panels. And it has the wording that will be listed on the panel label in that paragraph... (23)

    Also somewhere close to that paragraph it talks about if a panel uses the 6 disconnect rule that even though you may be able to exceed 6 disconnects with some combination of breakers there must be at least one combination that is exactly six disconnects and uses all the spaces in the panel.
    Roger,

    I think you are referring to this: (underlining and bold are mine)
    22. Some panelboards may have the required number of handles and service overcurrent devices, when the maximum number of the smallest units are installed and used without handles ties or similar devices. These panelboards may have the shorter marking “Suitable for use as service equipment” or “Suitable only for use as service equipment.” The shorter marking is suitable for Class CTL (circuit limited) lighting and appliance panelboards since they cannot have more than two main overcurrent protective devices as specified in Section 408.36(A) of the 2005 NEC.

    23. Class CTL lighting and appliance panelboards without main overcurrent protection usually are not marked suitable for service equipment use. Such panelboards, with not more than 10 percent of their overcurrent devices rated 30 amperes or less, however, may be suitable for use as service equipment. They are marked “Suitable for use as service equipment when not more than six main disconnecting means are provided and when not used as a lighting and appliance branch-circuit panelboard; see Section 408.34 of the 2005 NEC."

    24. A panelboard intended for service equipment use must have the marking “Service Disconnects” near the switch or circuit breaker handles. If this is not done in the factory, pressure sensitive labels must be provided. This marking identifies the service disconnects when branch disconnects are also present. This is required by Section 230.70(B) of the NEC.


    Jerry Peck, Construction / Litigation Consultant
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  32. #32
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    Roger Frazee Guest

    Default Re: 6 disconnect rule for detached residential garage

    Yes that is the section of the document I'm talking about. Anyway I am pretty sure I have the correct understanding now. It was a rather large surprise to me about this mlo panel I made example of not working as the building disconnect . In my experience there are many mlo panels out there that passed as the residential detached building disconnect under the 6 disconnect rule that would accept more than 6 disconnects and all of them are LA&BCP.


  33. #33
    John Steinke's Avatar
    John Steinke Guest

    Default Re: 6 disconnect rule for detached residential garage

    IF a disconnect is required, there are several ways it can be done. Local rules can greatly affect your choice.

    Some examples are:

    Simply back-feeding a breaker in the panel would meet the NEC rules, even if the panel is inside the garage, in the back.

    Many towns want there to be an outside disconnecting means. Again, this might be met by simply placing the panel itself outside.

    A separate disconnecting switch might be used. This can be something as simple as a full-current rated switch. Here's where the 'service rated' part kicks in; your typical HVAC disconnects might have the ampacity, but they lack any provisions for the neutral and for tying in the ground rod. (More than one circuit, you need a ground rod too- but that's another discussion).

    Another alternative is to have a simple snap switch operate a 'shunt trip' breaker in the panel. These are typically identified by a large red triangle. One of the quirks of the various codes is that while a 'disconnect switch' is usually required to be mounted less than 6-1/2 ft. from the ground, "shunt trip" switches are typically required to be located MORE than 7ft. from the ground. Go figure.

    A safety note: even when the disconnect to such a building is tripped, there may STILL be power present. One situation where this can happen is when outside lights on the building are controlled from the other building.


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