Pool And Radio

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domnic

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Electrical Contractor
If i drop a radio in a in ground pool that is bonded correctly will it trip the GFI the radio is plugged in to. (radio has two prong plug) no pool light just a steel ladder witch is bonded 30' away from the radio dropped in pool.
 
domnic said:
If i drop a radio in a in ground pool that is bonded correctly will it trip the GFI the radio is plugged in to. (radio has two prong plug) no pool light just a steel ladder witch is bonded 30' away from the radio dropped in pool.
Click to expand...

IMO, yes. which is why the new code change in 2008 to bond the water.
 
I believe that is the idea with the bonding of the pool water if it were not it may not trip
 
I guess I have to retract my statement that the use of a bonded section of metal piping will bond the water.
I just tried a jumper from a GFCI receptacle to running water at the bathroom sink. I have all copper water pipe except the flexible connection between the faucet and the pipe in the wall and the GFCI did not trip.
I would also question if a single 9 square inch metal object in the pool itself would really do the job.
 
domnic said:
If i drop a radio in a in ground pool that is bonded correctly will it trip the GFI the radio is plugged in to. (radio has two prong plug) no pool light just a steel ladder witch is bonded 30' away from the radio dropped in pool.
Click to expand...

Two or three prong cords make no differnce to a GFCI, they do not work off of the ground, they trip when there is a diffence in current between the hot and grounded conductors. if they are not equal, then current is flowing somewhere it isnt supposed to go.
 
domnic said:
If i drop a radio in a in ground pool that is bonded correctly will it trip the GFI the radio is plugged in to. (radio has two prong plug) no pool light just a steel ladder witch is bonded 30' away from the radio dropped in pool.
Click to expand...
When I read this, the first thing that came to my mind was: Who are you planning to kill. :cool:
 
It should trip even if pool is not bonded.The hot wire should be trying to go thru water and shell.Now if by some way out thing like perfect water then it would not.Try it by just throwing in a drop cord.Radios cost money.
 
ultramegabob said:
Two or three prong cords make no differnce to a GFCI, they do not work off of the ground, they trip when there is a diffence in current between the hot and grounded conductors. if they are not equal, then current is flowing somewhere it isnt supposed to go.
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In the case of the pool the cord can make a difference. If there is no path back to the power source, then the GFCI will not trip, however the live cord in the water can set up a hazardous voltage gradient. The three wire cord provides this path, assuming that the water is conductive enough to flow 5 mA between the hot and the EGC of the cord.
 
Jim W in Tampa said:
It should trip even if pool is not bonded.The hot wire should be trying to go thru water and shell.Now if by some way out thing like perfect water then it would not.Try it by just throwing in a drop cord.Radios cost money.
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Jim,
A path of ~2' of water in a non-conductive pipe would not trip my GFCI when I tried it tonight. The water was energized enough to make my non-contact tester show that it was energized but it did not flow enough current to trip the GFCI. If the pool has a fiberglass or other nonconductive shell the water may not conduct the 5mA required to trip the GFCI.
 
so what your saying is that there will be no differnce of current between the two conductors because they are both submerged and have no ground to leak to, or they leak equally?
 
ultramegabob said:
so what your saying is that there will be no differnce of current between the two conductors because they are both submerged and have no ground to leak to, or they leak equally?
Click to expand...
Yes, without another path back to the source (bonding and or grounding) there is no current imbalance and the GFCI will not trip, but the water will have voltage gradients. A three wire cord may provide a path between the hot and the EGC creating an imbalance that will trip the GFCI.
 
don_resqcapt19 said:
Yes, without another path back to the source (bonding and or grounding) there is no current imbalance and the GFCI will not trip, but the water will have voltage gradients. A three wire cord may provide a path between the hot and the EGC creating an imbalance that will trip the GFCI.
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Is this not the logic used to justify bonding the water in the first place???
 
The proposal for the pool water bonding only talks about the elimination of potential between the water and the bonded pool deck. I have heard (and repeated) other statements that said part of the reason was to make sure that a GFCI would trip. That statement appears to be in error. However, given my informal test, I don't see how you can bond all of the water in the pool with a single 9 square inch bonding point. I guess I need to get some pool water to test as it is likely somewhat more conductive than the tap water that I tested with.
(680.26(C) (New) )
____________________________________________________________
Submitter: Frank C. Lambert, Georgia Tech/NEETRAC / Rep. National
Electric Energy Testing, Research, & Applications Center
Recommendation: Insert a new Section 680.26(C) as follows:
680.26(C) Pool Water. An intentional bond of a minimum conductive surface
area of 5806 mm 2 (9 in 2 ) shall be installed in contact with the pool water.
This bond shall be permitted to consist of parts that are required to be bonded
in 680.26(B).
Renumber the present sections sequentially from (C) to (D), (D) to (E), and
(E) to (F).
Substantiation: Bonding of metal parts in and around a swimming pool to an
equipotential bonding grid is extensively covered in 680.26. The intent of this
bonding is to equalize the voltages between the pool water and the deck
including any attached metal structures or parts. 680.26 has been effective in
mitigating stray voltage problems, especially in the case of fiberglass
swimming pools or pools with insulated liners.
680.26 describes various metal parts and equipment that require bonding with
an equipotential bonding grid. In describing these metal parts, it is assumed
that one or more of the parts are in contact with the pool water. This may not
always be the case. Some pools do not have any bonded metal parts in contact
with the water. In such a case, intentional bonding of the water is necessary to
equalize the water-to-deck voltages. Presently, 680.26 does not have a
provision for intentional bonding of the pool water.
Panel Meeting Action: Reject
Panel Statement: The submitter has not provided adequate substantiation.
There are issues such as conductivity of water, changes with water temperature,
current flow, size of conductors, etc. that need to be addressed.
Number Eligible to Vote: 11
Ballot Results: Affirmative: 9 Negative: 2
Explanation of Negative:
HIRSCH, B.: The testing done by the National Electric Energy Testing,
Research and Applications Center (NEETRAC) clearly substantiates that the
potential for shock hazard is increased in pools where the pool water is not
bonded via metal parts in the pool. Results of this testing were reported to
Panel 17 at the proposal meeting in January of 2006. Based on this testing, EEI
supports the adoption of this proposal and as such is voting negative to the
panel?s action. At the proposal meeting, Panel 17 indicated they had additional
questions that needed to be answered before supporting this proposal. The
panel statement, however, did little to document those concerns. Just as the
submitter needs to provide compelling substantiation for a code change, the
code panel has the responsibility to provide a justifiable technical basis to
reject well supported proposals.
JHONSON, D.: I agree with the Submitter?s substantiation, and, in addition,
the substantiation of the NEETRAC testing results reported to Code-Making
Panel 17 at the ROP meeting in January of 2006. I have provided additional
relevant pool test results from a project supervised by the university of
Newcastle, Australia and sponsored by Energy Australia. This reports a
potential shock hazard when conditions exist effectively bridging the isolation
of the pool water provided by an insulated pool shell.
This issue should be revisited.
Note: Supporting Material is available for review at NFPA headquarters.
____________________________________________________________

17-98 Log #802 NEC-P17 Final Action: Accept
(680.26(C) (New) )
________________________________________________________
Submitter: Frank C. Lambert, Georgia Tech/NEETRAC
Comment on Proposal No: 17-122
Recommendation: Proposal 17-122 should have been adopted in its entirety.
Substantiation: Extensive testing clearly substantiates that the potential for
voltage gradient is present in pools where the pool water is not bonded via
metal parts in the pool. With this knowledge and confirmation of a voltage
gradient hazard, the CMP must address the issue. Test results, handed out at
the Proposal Meeting, show that the presence of a touch potential exists in all
areas of the pool and that the proposed solution for bonding pool water will
essentially reduce that potential to zero. While the proposed solution may
not be the only solution, it meets the NEC criteria of providing minimum
protection for the public. The test report in its entirety has been submitted to
this Comment for further review by the Panel Members.
Typically, pool water is considered electrically conductive due to dissolved
chemicals. Although the conductivity will vary with the temperature, the
change in conductivity for all practical purposes is not a factor in the
application of a proposed solution. Again, the proposed solution meets the NEC
criteria of providing minimum protection for the public and should be viewed
as a protection measure compared to having no protection.
In the proposed solution, the size of bonding conductor is not specified. This
is in line with several Bonded Parts described in 680.26(B). In 680.26(B)(1),
(B)(2), (B)(3), and (B)(5), use of a minimum of #8 AWG size wire is implied
as specified in 680.26(B)(4) and 680.26(C).
In the stray voltage field, ground currents are rarely determined due to
measurement difficulties and inaccuracies. On the other hand, resulting
voltage gradients (stray voltages), however, are very easy to measure and
can be directly used to analyze stray voltage problems and their mitigation.
As evidenced by the test report, the proposed solution is based on such stray
voltage measurements around a swimming pool.
Note: Supporting material is available for review at NFPA Headquarters.
Panel Meeting Action: Accept
Number Eligible to Vote: 11
Ballot Results: Affirmative: 9 Negative: 1
Ballot Not Returned: 1 Gill, C.
Explanation of Negative:
CRIVELL, P.: Optimum solution is to eliminate stray currents causing the
voltage gradient. Code Panel 17 should address the cause and methods for
elimination of stray currents. Conductive metallic objects in chlorinated water
will result in electrolytic coupling issues.
________________________________________________________
Click to expand...
 
Pool water is more conductive,it has a higher total dissolved solid content up around 600 to 1200 ppm and pools with salt generators have a higher tds.

I came up with a bonding plate that will be easy and cost affective to use.
The bonding plate is made of stainless steel 3"x 4" witch is 12 square inches and the plate has a threaded stainless steel stud. This fits in the skimmer of the pool, all pools have skimmers. you drill a 1/4 inch hole in skimmer so the threaded stud can go through to the outside of skimmer to have a bonding lug attached to it.
 
I think there are a lot of misconceptions about water and electricity. The video of the hair dryer running in a sink full of water demonstrates that fact. I was also surprised to find that when I accidentally dropped the lit 120 volt fluorescent light fixture in our fish tank, the fish were unaffected and the light stayed on. I was a bit freaked out when it happened as the fish are my kid's beloved pets. She was standing next to me when I did it. My first thought was to quickly stick my hands in the water and pull out the light in order to save the fishies. My second thought was the possible effect of the voltage in a fluorescent fixture ballast on my wet little hands. Two voices in my head were arguing, "Fish!", "Electrician!" back and forth. No, I did not dive into the possibly energized fish tank to be a fish hero. I did, however, unplug the light as fast as I could and then got it out of the water.

The light and fish both came out unharmed. I think I was worse off than either as I thought as the light hit the water I was about to electrocute the poor fishies right in front of my daughter.

Yesterday I repaired some low voltage yard lights. One of the bulbs was in a below ground fixture half full of water, conductors on the bulb totally submerged, and the light worked fine.

I remember as a kid out fishing at night and seeing a buddy drop a regular old metal Ray-O-Vac flashlight overboard and watching it sink to the bottom of the lake, on all the way. (Since it was his light and he dropped it I did not volunteer to swim through the seaweed to go get it.)

I can't tell you how many cars I have worked on with the newer style headlights where the enclosure was full of water and the light still worked. While I was with Chrysler (around 1991) there was a recall on Caravans where we had to drill a drain hole in the headlamp enclosures to let the water drain out. *Many* came in so full of water it submerged the bulb and the lights still worked.

I have had cell phones and pagers go through the wash machine and still work. I had an earphone for one of my radios go both through the wash machine and the dryer and I still use it to this day.

I think the most amazing thing I encountered was working on a dump truck in the 70's to find that the electric fuel pump was totally submerged, by design, in gasoline. That is common today but not so way back then. I was troubleshooting a fuel gauge issue and was shocked (pun intended) to find an electric pump in the tank along with the sending unit.

It seems that when it comes to electrical devices submerged in liquid we have wisely chosen to err on the side of safety, but nonetheless, the fact that they have been observed to keep working when submerged makes for a fascinating subject to study. I want to do an experiment and see if an incandescent fixture can stay lit in a bucket of water someday. (Kids, don't try this at home!!)
 
A long time ago (in a galaxy far, far away :grin:), I was given a toy submarine kit that had a sealed compartment for the PM motor, but the battery (2 D cells) compartment was flooded for ballast.

I knew enough about electricity back then to ponder the whole idea, but it worked without a hitch. Naturally, I lost it long before I had the chance to try it in salt water. I wonder where it sailed off to?

Y'know, looking back, my early interests in electronics provided me with some neat toys and pastimes that other kids didn't experience. I built my first crystal radio from scratch when I was in the first grade.
 
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