Results 1 to 9 of 9
  1. #1
    Join Date
    Mar 2007
    Location
    Knoxville, TN
    Posts
    2,332

    Default Odd condition in fuse block

    I was checking a fuse panel today and found an odd condition. When I put my wiggy between the threaded part of the fuse block and a ground I got 120V. Got the same 120V between ground and the bottom of the fuse block. No other fuse block in the panel did the same.

    Nothing was connected to this block by the way.

    Similar Threads:
    ***IMPORTANT*** You Need To Register To View Images ***IMPORTANT*** You Need To Register To View Images
    NHIE Practice Exam

  2. #2
    Join Date
    Mar 2007
    Location
    Santa Rosa, CA
    Posts
    2,286

    Default Re: Odd condition in fuse block

    Jack,

    Sounds (weird thing to say when I didn't actually hear you say anything) to me like voltage is "backfeeding" into the panel from somewhere else. Did you remove the fuse to check that socket or was there no fuse in place?

    Department of Redundancy Department
    http://www.FullCircleInspect.com/

  3. #3
    Join Date
    Mar 2007
    Location
    Ormond Beach, Florida
    Posts
    25,317

    Default Re: Odd condition in fuse block

    Could be two things.

    First, that could be shorting out. Was it being used or was it already empty (no fuse in it)?

    It could also be that there was a multi-wire circuit or voltage back feeding as Gunnar stated.

    The center is hot - connected to hot.

    The shell is hot - connected to hot through the fuse.

    The wire coming off the shell is hot - when the fuse is installed.

    That wire could be getting voltage from something else, which in turn is showing up as the fuse shell being hot.

    If that voltage were on the same phase leg, it would not cause a problem, if on another phase leg, it would short out and blow fuses.

    It is quite possible that, at some point in time, some wires were interconnected and two circuits from two fuses got tied together somewhere.

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

  4. #4
    Join Date
    Mar 2007
    Location
    Knoxville, TN
    Posts
    2,332

    Default Re: Odd condition in fuse block

    fuse was not in, and there isn't a wire connected to the fuse anyway.


  5. #5
    Join Date
    Mar 2007
    Location
    Ormond Beach, Florida
    Posts
    25,317

    Default Re: Odd condition in fuse block

    Quote Originally Posted by Jack Feldmann View Post
    fuse was not in, and there isn't a wire connected to the fuse anyway.
    If there is no wire connected to that fuse's terminal, then the fuse holder must be shorted out in some manner.

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

  6. #6
    Join Date
    Mar 2007
    Location
    Knoxville, TN
    Posts
    2,332

    Default Re: Odd condition in fuse block

    I kinda thought that, just wasn't sure the mechanics of HOW?


  7. #7
    Join Date
    Mar 2007
    Location
    Santa Rosa, CA
    Posts
    2,286

    Default Re: Odd condition in fuse block

    Quote Originally Posted by Jerry Peck View Post
    If there is no wire connected to that fuse's terminal, then the fuse holder must be shorted out in some manner.
    Probably why there is no fuse in it.

    Department of Redundancy Department
    http://www.FullCircleInspect.com/

  8. #8
    Join Date
    Mar 2007
    Location
    Ormond Beach, Florida
    Posts
    25,317

    Default Re: Odd condition in fuse block

    Jack,

    There is usually an insulating washer/bushing under the center contact between it and the shell.It does not take much contamination to cause electrical leakage, which, over time, leaves an arc track. Also, like everything, those insulators age and deteriorate.

    Also, sometimes I've seen where the center contact comes in contact with the shell where the center contact penetrates the shell - where the slot in your photo is.

    If you zoom in on your photo, there is little to no space between the top of that center contact and the shell, right were the dark area is. I just zoomed in while typing this and even at 400 times zoom, the two pieces look like they are touching.

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

  9. #9
    Join Date
    Mar 2007
    Location
    Knoxville, TN
    Posts
    2,332

    Default Re: Odd condition in fuse block

    At 400X I guess my finger tip looks pretty cracked.

    Thanks for the responses. I talked to my client this evening, and the first thing on his plan is to replace all the panels and clean it up a bit. There were several ungrounded outlets, and he needs some dedicated circuits. He is planning on a lot of wiring anyway.

    We just see strange stuff sometimes, and about when we think we have seen most of it..................

    Thanks again. I really appreciate the answers.


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
  •