Results 1 to 9 of 9
  1. #1
    Join Date
    Mar 2007
    Location
    Spring City/Surrounding Philadelphia area
    Posts
    3,509

    Default Spliced Service Cable for Service to Garage

    Inspected this house yesterday. The service panel has a 200 amp cable that is spliced inside the panel above the connection to the main lugs. The spliced-in cable runs down through and out of the bottom of the panelbox and into a 150 amp disconnect for the subpanel inside a detached garage.

    The connection appears clean but I've never seen this type of installation before. Is this an allowable proper installation? If I understand correctly, the service panel interior is not supposed to be used as a junction box for a splice that is not connected inside the panel.

    Similar Threads:
    ***IMPORTANT*** You Need To Register To View Images ***IMPORTANT*** You Need To Register To View Images
    Inspection Referral
    "It takes a big man to cry. It takes an even bigger man to laugh at that man". - Jack Handey

  2. #2
    Join Date
    Mar 2009
    Location
    Colorado Front Range
    Posts
    684

    Default Re: Spliced Service Cable for Service to Garage

    Splicing in an enclosure containing over current devices is permitted with restrictions, which in the case of the pictured installation involve having the required space. This installation appears to meet the criteria.

    The NEC addresses this issue in 312.8. The article has 3 requirements for splicing in the enclosure. 2 of them are related to the total fill of the enclosure and fill at the cross section of the panel where the splice is made. The third requirement is a label indicating where the closest disconnect is for any feed through conductors. The conductors in the picture wouldn't be considered feed through, but an extension of the service conductors. Both the panel and the disconnect underneath would be considered service disconnects.

    Prior language in the NEC appeared to some people to indicate that a specific amount of space needed to be "provided" for splicing and that if that special space wasn't somehow indicated as being "provided" that splicing wasn't permitted. So, some inspectors wouldn't permit splicing unless a label on the enclosure specifically indicated that splicing was OK and space was provided for it. The language was clarified in the 2011 NEC to indicate that indeed, if the requirements for fill in the enclosure were met splicing was permitted.

    Occam's eraser: The philosophical principle that even the simplest solution is bound to have something wrong with it.

  3. #3
    Join Date
    Mar 2007
    Location
    Spring City/Surrounding Philadelphia area
    Posts
    3,509

    Default Re: Spliced Service Cable for Service to Garage

    Good info Bill. Thanks for your input. Sounds like this installation is OK.

    "It takes a big man to cry. It takes an even bigger man to laugh at that man". - Jack Handey

  4. #4
    Join Date
    Jun 2008
    Location
    Maryland
    Posts
    1,096

    Default Re: Spliced Service Cable for Service to Garage

    Hold on a minute. That original SEC now serves a 200amp main and a 150amp at another location. I'm not sure if I'd call the other panel with the 150amp a sub panel. Yes its spliced inside of the panel but not fed through the panel. It is acting as a separate SEC right? So it's two separate service panels the way I see it. A 200 and a 150. So thats a potential of 350. Even if the original SEC is a 4/0, its only rated for 200. I see potential for the SEC to be overloaded. Its over fused.

    - - - Updated - - -

    My bad. Maybe garage is a sub panel if its fed by the 150 disconnect. But I still see 200 + 150 potential on that SEC. That's gotta be wrong...


  5. #5
    Join Date
    Mar 2009
    Location
    Colorado Front Range
    Posts
    684

    Default Re: Spliced Service Cable for Service to Garage

    The right or wrong of whether or not the service conductors are "big enough" is determined by the connected (calculated) load. The "potential future" load doesn't enter in to sizing a service, which is why adding circuits should only be done by someone who can calculate the load on the service equipment. You may not like it, but them's the rules.

    I would suspect that the large size service conductors to the garage are because there are provisions for a welder. Even if not, the load calculations for the house and garage are what needs to be taken into account, not the size of the service disconnect for each.

    Last edited by Bill Kriegh; 08-30-2018 at 08:19 AM.
    Occam's eraser: The philosophical principle that even the simplest solution is bound to have something wrong with it.

  6. #6
    Join Date
    Jun 2008
    Location
    Maryland
    Posts
    1,096

    Default Re: Spliced Service Cable for Service to Garage

    Quote Originally Posted by Bill Kriegh View Post
    The right or wrong of whether or not the service conductors are "big enough" is determined by the connected (calculated) load.
    But if I see a 200 amp main being fed by a 2/0 AL SEC, thats wrong. Am I correct here?

    The point I'm making is the splice in that service panel is prior to the main breaker, therefor the load on the spliced conductors are not governed by the 200 amp main, they are an addition to it. The added load is not covered by the main in the service equipment. This clearly leaves "potential" for an overloaded SEC upstream of the splice. You could have 150 amps being drawn by the main service equipment, and another 100 being drawn by the sub panel in the garage. Neither breaker would trip and the SEC upstream of the splice would be flowing 250 amps, which is in excess of its rating.

    Possible, yes or no?


  7. #7
    Join Date
    Mar 2009
    Location
    Colorado Front Range
    Posts
    684

    Default Re: Spliced Service Cable for Service to Garage

    Sure. ANYTHING is possible. But again, the OPs installation is permitted if the calculated load doesn't exceed the service conductor rating.

    Rules are different if there is a single over current protection device.

    If you have access to the NEC what you are looking for is article 230.90 exception 3.

    The rules were never written for John Q to be arbitrarily stuffing circuits into a panel.

    Occam's eraser: The philosophical principle that even the simplest solution is bound to have something wrong with it.

  8. #8
    Join Date
    Aug 2008
    Location
    Maryland
    Posts
    1,970

    Default Re: Spliced Service Cable for Service to Garage

    I would say it is an issue as the unfused conductors are not as short as practical. The tap rules are rarely applicable in residential work.

    Last edited by Jim Port; 09-02-2018 at 03:59 AM.
    All answers based on unamended National Electrical codes.

  9. #9
    Join Date
    Mar 2009
    Location
    Colorado Front Range
    Posts
    684

    Default Re: Spliced Service Cable for Service to Garage

    Well Jim, I guess "practicable" is in the eye of the inspector (AHJ).

    Given the train wreck visible in the pictures, I'd say the addition of the garage circuit was a well done piece of work, based on what I can see. However, there appears to be framing that intrudes on the required work space but without a full view picture it' s hard to tell. And whether or not this was installed after the electrical installation would change my opinion about things being a good install.

    There are other violations present in the pictures that have nothing to do with the garage wiring but the OP didn't ask about anything else.

    At any rate, similar type installations aren't rare in my part of the world and this one is infinitely better than a lot of the hack jobs I've run across. Done from scratch there are definitely better ways to put things together.

    Occam's eraser: The philosophical principle that even the simplest solution is bound to have something wrong with it.

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •