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Thread: GFI failures

  1. #1
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    GFI failures

    What are the common failure modes of GFI's?

  2. #2
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    Quote Originally Posted by coburn1 View Post
    What are the common failure modes of GFI's?
    Improper installation of the CT's and wiring direction (Zero sequence systems). CT polarity backwords (Summation type systems). Ground connection on wrong sid eof nuetral disconnect.

  3. #3
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    GFCI's or GFPs

  4. #4
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    Quote Originally Posted by brian john View Post
    GFCI's or GFPs
    Sorry. GFCI. I wanted to know common failure modes for GFCI that have been properly installed and subsequently fail.

  5. #5
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    i'm no electronics expert, but I've dissected a bunch of GFCI receptacles that have gone bad. Most of them showed blackening or damage to the tracers between the trip coil and one of the resisters.

    Failure rate on GFCI's seems to have gone down over the last few years. We used to between 2.5% to 5% natural failure rate regardless of brand, and now it seems closer to 1%.

  6. #6
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    Quote Originally Posted by coburn1 View Post
    Sorry. GFCI. I wanted to know common failure modes for GFCI that have been properly installed and subsequently fail.
    Oh, thats different, disregard my post in that case.

  7. #7
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    The receptacle type or breaker type? Someone (one of the Roger's I think) did a test a while back of the receptacle type and discovered that the GFCI portion failed a lot on circuits that had tripped due to a short circuit or other high current fault. Seems the current surge took something out and killed the GFCI circuitry.
    Mark
    Kent, WA

  8. #8
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    090215-0853 EST

    Failure of a semiconductor device can be a reason for the coil to burn up. Some failures, such as the main MOV, may not affect the coil.

    ELA made a video of what can happen with a failure that causes the coil to overheat. See
    http://forums.mikeholt.com/showthrea...ght=gfci+video

    .

  9. #9
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    Feb 2009
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    Thanks very much. I especially enjoyed the GFCI experimental work.

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