Outlet next to bathtub

[Jim Katen]

Jim,

Would that GFCI trip if you stuck your finger in the water?

The answer is very interesting.

In fact, if I stick my (impeccably clean) finger in the water, the GFCI does not trip. However, if I then swish my finger around, it trips.

This interested me. I eventually found that my finger was not necessary. If I stick the wires in still tap water, nothing happens. However, if I agitate the water, even if only by moving the glass, the GFCI trips. Agitation seems to be the key.

I don't know why this happens, but I suspect that my particular tap water is not quite conductive enough to trip the GFCI on its own, but it's really close. Perhaps by agitating the water, I'm causing the ions to move around, making & breaking connections as they go and increasing the chance of lining things up, if even temporarily, so that they cause the GFCI to trip.

Plausible?

Any other explanations?

- Jim Katen, Oregon

[JEuriech]

A long time ago, I worked in the water treatment field. We sold water treatment for boilers, chillers, and cooling towers.

The conductivity of water is based on total dissolved solids. Pure water is not a good conductor of electricity. As total dissolved solids increase, conductivity will increase. Even distilled water has enough dissolved solids to conduct electricity under the right conditions. For absolute pure water, we would use double distilled water for testing purposes.

We used a TDS (total dissolved solids) meter for our testing in the field. It worked on the same principle as an ohmmeter. By testing the resistance of water, you can determine the level of dissolved solids or how well it will conduct electricity.

We would not use an ohmmeter because it was hard to control all the variables. The amount of water used, how far the probes went into the water, the spacing on the probes, etc. A TDS meter made our life simpler.

It is sort of fun to take a ohmmeter and test the resistance of water. However, keep all the variables the same throughout your testing. Try hard water, soft water, RO water, and even distilled water. You will find some interesting results. With distilled water, look at you reading, then stick your finger in the water and swirl it around. You will be able to see the resistance of the water change on your meter.

While absolute pure water will not conduct electricity, I still will not stick my finger in a glass of water that has power going to it. However, I have seen other salesman/servicemen do it.

If you do a search on the internet, you can find a ton of information. See some of the following examples.

Jeff Euriech

Peoria Arizona

http://water.epa.gov/type/rsl/monitoring/vms59.cfm

http://www.lenntech.com/applications/ul ... tivity.htm

.

[Tom Raymond]

Loose connection at the GFCI? Put a plug on the end of that romex and try again.

Oh, and hold a light bulb in your mouth like Uncle Fester. [:-bulb]

[Jim Baird]

How about this one for convenience?

Click to Enlarge

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