Basement flood--why did the breakers not trip?

Discussion in 'Bad Dog Cafe' started by maxvintage, Jul 22, 2019.

  1. maxvintage

    maxvintage Friend of Leo's

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    We had an unprecedented flood around here two weeks ago, and ended up with three feet of water in our basement, which had been bone dry for twenty years. Big disaster.

    But here's my question--even though the water was above the wall outlets for a couple hours, none of the breakers on the panel tripped. Where there were GFCI's in a circuit, they failed. But for example we had an LED nightlight at the foot of the basement stairs, and it remained lit underwater. We never lost power in the house.

    We had the house electrical service upgraded two years ago--new ground rods pounded in outside and a ground wire added to the main water pipe. The basement outlets were all modern wiring.



    Can anyone explain this?
     
  2. smartsoul72

    smartsoul72 Tele-Meister

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    Breakers trip when there's a short or theyre overloaded. The GFCIs sense the imbalance in the circuit. Just having the wiring under water wasnt enough to trip the breakers, but your GFCIs did their job
     
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  3. maxvintage

    maxvintage Friend of Leo's

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    Why did being underwater not cause a short?
     
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  4. danlad

    danlad Tele-Meister

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    Unless you were flooded by the local distilled water factory I've no idea.
     
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  5. Teleterr

    Teleterr Friend of Leo's

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    When I use to build docks we would run extension cords from shore to our floating barge. Where the cords plugged together would be under SALTWATER sometimes. Its a better conductor than fresh water, but way more resistance than Copper. So no problem. I was careful to wear both rubber boots and elbow length rubber gloves when using the drill tho.
     
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  6. Teleterr

    Teleterr Friend of Leo's

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    Distilled has more resistance than Fresh.
     
  7. darren7

    darren7 Tele-Holic

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    Distilled water does not conduct electricity. It’s the ions from dissolved metals and salts that act as conductors.
     
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  8. Obsessed

    Obsessed Telefied Ad Free Member

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    Unless you know the circuitry in your basement, the GFCIs Probably did the job. They protect like a circuit breaker between the fault outlets and the actual circuit breakers extending out from the GFCIs. With flooding as a possibility, maybe your updated wiring included the GFCIs to protect all of the basement outlets. It could possibly only take one GFCI if your basement wiring is on one circuit.

    BTW, I would have all of your basement outlets inspected for corrosion or better yet, just replaced.
     
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  9. maxvintage

    maxvintage Friend of Leo's

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    No but here's the thing--most of those outlets DID NOT have GFCI's in them, and as mentioned, they still worked after the water went down. The GFCI's are a different issue. I don't understand how a row of outlets without a GFCI in the circuit can be underwater for several hours without tripping a breaker.


    I plan to replace them but we need to have asbestos tile removed first
     
  10. Bones

    Bones Telefied Ad Free Member

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    All I know is that after hurricane Sandy, the houses around me that got flooded and like yours kept power through the storm, all burned down a week to 10 days later as the houses dried out and the wiring began to corrode.
     
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  11. adamkoop

    adamkoop Tele-Meister

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    As I understand them, GFCIs measure for an imbalance in their own current out / current return loop. The idea being that if you are in the circuit and flowing current through yourself to ground directly, rather than back through the outlet's return, it will detect that and shut down. In the case of the outlet itself being underwater, the return is going to be through the outlet, and not some other path most likely. Assuming the GFCI circuit wasn't damaged by being underwater.

    As for the mains breaker not tripping, the high resistivity of the water likely didn't allow the requisite current to flow. Assuming you need 20A to trip the breaker, you'd need a load under 6 ohms at 120V to get that current.
     
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  12. Obsessed

    Obsessed Telefied Ad Free Member

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    The outlets don't need a GFCI in those positions. Each basement circuit potentially would only need one GFCI outlet somewhere up stream. One GFCI outlet can protect many standard outlets depending upon how they are wired.
     
  13. magicfingers99

    magicfingers99 Friend of Leo's

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    Breakers don't work on plumbing. you need shutoff valves on plumbing. breakers are for lectrixity.

    city folks...
     
  14. Milspec

    Milspec Friend of Leo's

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    One of my professional past duties was flood restorations and to answer your question, the breakers will not trip if there are GFCI's installed. If they are not GFCI outlets, then they should trip a breaker unless the water is too clean. Water itself will not cause the circuit to short, it is the minerals / metals that exist in dirty water that causes the short.

    As was also noted, wiring that has been under water need to be fully inspected / replaced prior to placing the home back into service. Compromised wiring like that often triggers a house fire later if not corrected.

    If you need any advice on dealing with the remediation, let me know. There are some real vampires in that industry so be on your guard.
     
  15. Milspec

    Milspec Friend of Leo's

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    Asbestos tile....floor tiles? The tiles themselves are not asbestos, just the adhesive used to mount them. As long as the adhesive is not exposed, there isn't a problem. Most of the time, another layer of tile is installed over the old to encapsulate it and save money.
     
  16. magicfingers99

    magicfingers99 Friend of Leo's

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    don't tell that to the lighting bolts that shoot between clouds and ground.

    if the voltage is high enough or the amperage, the electrons will seek the path of least resistance and are pretty agnostic about the type of material involved.

    basically at a high enough charge an insulator becomes a conductor. good to respect electricity, it can give a shocking education if you survive it.
     
  17. magicfingers99

    magicfingers99 Friend of Leo's

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    if water compromised insulated wiring, wouldn't all the buried electrical cables catch fire every time it rains? Seems like just another way to charge a fee...
     
  18. charlie chitlin

    charlie chitlin Doctor of Teleocity Silver Supporter

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    Read this again.
    This post is the money.
     
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  19. Blrfl

    Blrfl Tele-Holic

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    Ohm's law makes this pretty easy to figure out:

    Rain water has a resistance of about 20KΩ, so immersing contacts being fed at 120V will flow current of about 0.006A. Tap water is 1-5KΩ depending on how hard it is, which puts the worst case for that at 0.12A.

    Neither is enough for the breakers to notice. Their job is to break the circuit when too much current is flowing so the wires don't overheat and burn their insulation. They don't care if the load at the end is an electrical appliance or you, just as long as there isn't too much current. A submerged GFCI outlet won't trip, either, because any current flow from the conductors through the water will be to ground. That's exactly what the breaker expects.

    Some flavors of GFCI breaker have terminals that will let you create a ground fault and force a trip, much like the test button on some GFCI outlets. If you want the power shut off in your basement when it floods, you'll need to install a water sensor and have it trip the breaker like an emergency power-off button would do.
     
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  20. Milspec

    Milspec Friend of Leo's

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    Wiring in the house is up agaisnt flammable materials....not that way in the ground.
     
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