Did the GFCI really save my insurance agent?

[hockeyoligist2]

I spent a little time with my insurance agent this morning, not job, homeowners and vehicle INS. I've know him a few years and he knows I'm an electrician. He loves to tell stories. Maybe to send me off track so I don't notice extra charges!

He said that his basement flooded and he stepped in to the water to check things out and heard a click as soon as he stepped in. In the direction of his dehumidifier. After he pumped it down he found that the GFCI on his dehumidifier was tripped and thinks that it happened when he touched the water.

Wouldn't it have tripped from the dehumidifier being under water first? Or could he have triggered it?

 

[Dennis Alwon]

It depend. If it is a 2 wire gfci it will run underwater till the motor burns out without tripping the gfci. If it were a 3 prong unit then I would think the gfci would trip.

BTW, I did an experiment at our local contractors meeting that blew them all away. I took an empty plastic staple bucket filled with water. I wired a porcelain socket to a 2 wire cord. The porcelain had no box either, I stuck a wp flood bulb in the socket and dropped it in the bucket. The gfci did not trip. To make it more interesting I stuck my hand in the water and it still did not trip. I took a tester and had about 20V to ground at the top of the bucket but as I moved the tester closer to the socket it tripped the gfci.

 

[hurk27]

To say it saved him would be a tough one, as they were probably more non-GFCI circuit in this basement that could have been a problem.

First a GFCI only requires a path of 24,000 ohm's impedance to trip @ 120 volts, that's at .005 amps, I find it most likely that even if the circuit had no EGC all the way back to the panel this would have been very easily achievable just between the hot and the concrete floor and or walls of the basement all submerged in water.

In Dennis's experiment there was no alternate path back to source because of the water being in a plastic container that it self was isolated, it wasn't until he introduced an alternate return path (meter) that the GFCI did trip, with just the hot and neutral in the container of water current can flow all the way to the point of tripping the breaker, I would think a conductive mineral would have to be added to reach that point like salt, but as long as the current flowing upon the hot is equal to the current flowing upon the neutral the GFCI will allow the full capacity of the circuit to flow without tripping.

Now for the matter of having live circuits underwater in a flooded basement, each open live connection with the water will have a voltage shell around this point or each of these points, these will be very similar to the shells we have discussed on ground rods and or other electrodes, current does not flow in a single path from point A to point B but will flow through all paths back to source, the most dangerous place will be near the point the voltage in injected into the water, this is anywhere there is a exposed live conductor in contact with the water, the shell around this point will have the greatest voltage drop and if you are within this shell you will become part of the return path, as you move away from this point the water will have lesser and lesser of a voltage drop because there will be more and more paths back to source, but we must remember, the human body can maybe not have a problem with 30 volts out of water, if you are submerged it can be a big problem down as low a 1 to 3 volts, there has been cases of persons not being able to move as low as 1 volt of stray voltage while submerged and drowned just because they could no longer swim.

So in essences no flooded basement is safe if there is still live circuits in it, do not enter any water until all electric has been turned off, this might require the POCO removing the meter or what have ya but, it is not worth the chance, and this HI should have not even thought about entering this water until this was done.

 

[tkb]

Let him think that your work saved his life. You might get a discount. :lol:

 

[kwired]

If he did cause it to trip it was because he add enough (fault) load somehow to get above the 4-6 mA trip point that maybe had not been reached before. If the entire 4-6 mA passed through him he definately would have felt the results.

 

[weressl]

I spent a little time with my insurance agent this morning, not job, homeowners and vehicle INS. I've know him a few years and he knows I'm an electrician. He loves to tell stories. Maybe to send me off track so I don't notice extra charges!

He said that his basement flooded and he stepped in to the water to check things out and heard a click as soon as he stepped in. In the direction of his dehumidifier. After he pumped it down he found that the GFCI on his dehumidifier was tripped and thinks that it happened when he touched the water.

Wouldn't it have tripped from the dehumidifier being under water first? Or could he have triggered it?

I would say no - based on the scarce data available - but he deserves the Darwin award of stepping in the water in the first place.

 

[steve66]

If he had caused it to trip, he probably would have felt a shock.

The GFI probably tripped long before he stepped into the water.

 

[iwire]

If he had caused it to trip, he probably would have felt a shock.

Great point, I agree 100%.

 

[hockeyoligist2]

Great point, I agree 100%.

I agree also, I didn't tell him that though. I just warned him to never step in to standing water if it flooded again, unless he turned off the main breaker and was sure there was no power on.

 

[pfalcon]

I would say no - based on the scarce data available - but he deserves the Darwin award of stepping in the water in the first place.

Can only get honorable mention since he can still reproduce. And the situation is too common to qualify even for that.

 

[LJSMITH1]

What about the 'waves' he made to the water level when he stepped into the flooded basement? If the humidifier motor or other energized parts were just above the water level when the water was still, then the GFCI wouldn't have tripped. Typically, with most dehumidifiers, the motors and other energized components are at the top half of the unit.

Once he stepped in the water, the water level rose slightly as it ran into the dehumidifier's energized components.

 

[nosparks1]

As in Deniss's experiment with the bucket of water is the problem with a lot of new installations where sinks are involved. Even with a stainless steel sink, most plumbing pipes both drain and water are not metal and grounded so if you drop a 2 wire cord appliance into the water filled sink, the GFCI the appliance is protected by probably will not trip.

 

[jeremysterling]

I'm still trying to picture the HO's fault circuit. Did he hold on to some overhead metal piping as he stepped into the water?

 

[rt66electric]

What kind of shoes were you wearing?

What kind of shoes were you wearing?

At the time of the experiment were you wearing leather soled shoes?? I assume not.. Did you at any time touch a grounded surface??

I was in the garage ( hard concrete) wearing tennis shoes, and touble shooting a dewalt batter-and-charger. I had the plastic cover apart and the battery in charge mode testing each cell for voltage for a faulty one. I touched the metal battery shell ,and recieved no shock.-------- I came back later without shoes -bare feet- grabbed the battery metal shells to remove them from the charger and the jerk-back from the shock threw the battery across the shop. GFCI DID NOT TRIP .

To say it saved him would be a tough one, as they were probably more non-GFCI circuit in this basement that could have been a problem.

First a GFCI only requires a path of 24,000 ohm's impedance to trip @ 120 volts, that's at .005 amps, I find it most likely that even if the circuit had no EGC all the way back to the panel this would have been very easily achievable just between the hot and the concrete floor and or walls of the basement all submerged in water.

In Dennis's experiment there was no alternate path back to source because of the water being in a plastic container that it self was isolated, it wasn't until he introduced an alternate return path (meter) that the GFCI did trip, with just the hot and neutral in the container of water current can flow all the way to the point of tripping the breaker, I would think a conductive mineral would have to be added to reach that point like salt, but as long as the current flowing upon the hot is equal to the current flowing upon the neutral the GFCI will allow the full capacity of the circuit to flow without tripping.

Now for the matter of having live circuits underwater in a flooded basement, each open live connection with the water will have a voltage shell around this point or each of these points, these will be very similar to the shells we have discussed on ground rods and or other electrodes, current does not flow in a single path from point A to point B but will flow through all paths back to source, the most dangerous place will be near the point the voltage in injected into the water, this is anywhere there is a exposed live conductor in contact with the water, the shell around this point will have the greatest voltage drop and if you are within this shell you will become part of the return path, as you move away from this point the water will have lesser and lesser of a voltage drop because there will be more and more paths back to source, but we must remember, the human body can maybe not have a problem with 30 volts out of water, if you are submerged it can be a big problem down as low a 1 to 3 volts, there has been cases of persons not being able to move as low as 1 volt of stray voltage while submerged and drowned just because they could no longer swim.

So in essences no flooded basement is safe if there is still live circuits in it, do not enter any water until all electric has been turned off, this might require the POCO removing the meter or what have ya but, it is not worth the chance, and this HI should have not even thought about entering this water until this was done.

 

[kwired]

At the time of the experiment were you wearing leather soled shoes?? I assume not.. Did you at any time touch a grounded surface??

I was in the garage ( hard concrete) wearing tennis shoes, and touble shooting a dewalt batter-and-charger. I had the plastic cover apart and the battery in charge mode testing each cell for voltage for a faulty one. I touched the metal battery shell ,and recieved no shock.-------- I came back later without shoes -bare feet- grabbed the battery metal shells to remove them from the charger and the jerk-back from the shock threw the battery across the shop. GFCI DID NOT TRIP .

4-6 milliamps needed to trip the GFCI does not seem like a lot, until it is passing through you. This is a good example of how such a low current can really cause serious issues with the human body.

 

[hornetd]

I would say no - based on the scarce data available - but he deserves the Darwin award of stepping in the water in the first place.

If I understand the Darwin Award criteria he would have to have died prior to having fathered a child thus eliminating his particular gene arrangement from the gene pool.
--
Tom Horne

"Tommy sometimes the gene pool seems to be in need of a stiff dose of Chlorine." A now deceased fire captain who I worked under years ago.

 

[pfalcon]

If I understand the Darwin Award criteria he would have to have died prior to having fathered a child thus eliminating his particular gene arrangement from the gene pool.

Reasonably unique method that prohibits FUTURE procreation. Does not require death nor does it have to precede procreation. There's an introduction on the site for qualifications.

 

[sameguy]

We just replaced a 6 meter stack that was 3 feet under water w/ 200A and 100A main brkrs. Not trips, shorts, nothing, lights were on when the POCO came in, per the POCO guy. 3phase 208v/120v

 

[K8MHZ]

At the time of the experiment were you wearing leather soled shoes?? I assume not.. Did you at any time touch a grounded surface??

I was in the garage ( hard concrete) wearing tennis shoes, and touble shooting a dewalt batter-and-charger. I had the plastic cover apart and the battery in charge mode testing each cell for voltage for a faulty one. I touched the metal battery shell ,and recieved no shock.-------- I came back later without shoes -bare feet- grabbed the battery metal shells to remove them from the charger and the jerk-back from the shock threw the battery across the shop. GFCI DID NOT TRIP .

GFCI's, as you found out, do NOT prevent shock, nor are they designed to do so. They DO reduce injuries and fatalities.

I am still shaking my head over this one.....I really can't believe that someone in our trade would ever attempt to work on any sort of electrical equipment while standing barefoot on a concrete floor.

Your lucky you didn't get killed. Since it's obvious muscle contraction was involved, enough current may have went through you to cause afib.

 

[K8MHZ]

So in essences no flooded basement is safe if there is still live circuits in it, do not enter any water until all electric has been turned off, this might require the POCO removing the meter or what have ya but, it is not worth the chance, and this HI should have not even thought about entering this water until this was done.

That was the consensus of a friend of mine. He had the need to power wash a basement and wanted me to come over and pull the main and make sure that all the power in the house was off before he started to spray.

Sure, I said. :roll: I planned on hanging around to watch. This friend is the type that can tear stuff apart and fix it, like me. I was hoping to see how much of the power washer he would have apart before he realized that there was no power getting to the power washer.

A short while later, he called me back, realizing his error.

Darn it!!!! :lol: