Swimming Pools or Natural Body of Water

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hurk27

Senior Member
The problem with these types of pools is we tend to think that because there is no electrically supplied equipment around the pool that there is no danger of a shock problem, but we all know that some time in the future someone will eventually even if it is by an extension cord bring a electrically supplied equipment by the pool even if it is for a radio, or at some time later they might want lights added.

Stray voltage is a local event and stray voltage must be brought into the area via a low impedance path, a isolated pool like this would not have a problem of any voltage gradients as long as there is no low impedance path brought to the pool, it would remain at the potential of earth, the myth that a primary line fault a few hundred feet away can cause a voltage to travel through earth is false, most all stray voltage is caused within 25' of the area and its mostly cause by an elevated voltage of grounding conductors from a service that also has an elevated voltage to earth, stick a ground rod into earth and 25' away you will have dropped 100% of the voltage applied to the ground rod and the earth would be back at the potential of earth, of course this depends upon the conductivity of the soil but for most coagulations it works, the higher the resistivity of the soil the larger the sphere of influence around the rod and shells, so a soil with a lower resistivity will have even a smaller shell like 23'.

So we are back to the problem of someone bringing in a conductive path that would cause the stray voltage, who is to say that someone might want to listen to a radio at some future point and run an extension cord out there or at a later time install some lighting, we all know at this time no one will put an EPB system in and someone could be killed, My view is if the pool is intended for people to get in then a EPB system in needed, there is no requirement for it to be connected to the service grounding as this is not the purpose of it.
 

Dennis Alwon

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Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Take the original pic I posted and take out the obvious pool structure in the middle where the area tapers as a pond would. So now you have a deep middle section and shallow perimeter where plants grow. Why is this a pool? Simply because I installed a membrane? No chemicals but there is filtration. Chemicals make the water much more conductive- hence the difference in the code between a hot tub and hydromassge tub.

So now there is no obvious structure difference and the entire area looks like a pond.
 

Dennis Alwon

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Location
Chapel Hill, NC
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Retired Electrical Contractor
I was thinking something like this


ry%3D400
 

Dennis Alwon

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Retired Electrical Contractor
Then there is this. I wonder if seeing the pic below if an inspector would even consider this a pool? I just muddied the water here--- pun intended.

ry%3D400
 

ritelec

Senior Member
Location
Jersey
Then there is this. I wonder if seeing the pic below if an inspector would even consider this a pool? I just muddied the water here--- pun intended.

ry%3D400

Yep still trying to understand this a bit....

If God (or nature) makes a hole and fills it with water, theres no epg necessary.
If Man makes a hole and fills it with water, a epg is necessary.


OK ???

I understand this to a point.
It makes sense to me that if the utility companies turned off the switch we could all swim in peace..... :D
 

Dennis Alwon

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Location
Chapel Hill, NC
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Retired Electrical Contractor
Yep still trying to understand this a bit....

If God (or nature) makes a hole and fills it with water, theres no epg necessary.
If Man makes a hole and fills it with water, a epg is necessary.


OK ???

I understand this to a point.
It makes sense to me that if the utility companies turned off the switch we could all swim in peace..... :D


I think it is more than making a hole-- I believe throwing in the pumps changes it a bit-- a pond with no circulating pump would be fine but ....

Of course if this stuff is listed as natural pools then that would make it a pool but I think it is just a rubber membrane so you call it what you like...
 

hurk27

Senior Member
I think it is more than making a hole-- I believe throwing in the pumps changes it a bit-- a pond with no circulating pump would be fine but ....

Of course if this stuff is listed as natural pools then that would make it a pool but I think it is just a rubber membrane so you call it what you like...

Boy do you like to have interesting subjects:huh:

I see your point with these photo's, and your right it would be no different then a natural pond, but like I said before if it is intended for swimming and you are running any electrical circuits out by it, then I would tell them they need an EPB system and explain why, but if they don't want it or the extra cost, and if for some reason the inspector also sees it their way, I would make sure I have it in writing and signed that they refused to allow you to put one in, and including the point that the inspector also signed off on it.

I got to ask how are you involved with this pond? I don't remember you being in the pond installation business?, unless you are running circuits out to it?
 

kwired

Electron manager
Location
NE Nebraska
I don't do pools at all, nevertheless, this is an interesting thread. In a regular pool, is the equipotential bonding to protect against faults in the lighting system, pump system or both? If the pump is a factor, would some kind of belt driven pump (which eliminates any possibility of the water becoming energized by a fault in the pump) or a 12V pump eliminate the need to build the equipotential bonding?
The equipotential bonding is not for fault clearing, though it does help with that, fault clearing is the job of equipment grounding conductors run to the equipment that may have a fault. The purpose of EPB is to bring every conductive object within the user's reach to the same potential. A pool with no connection whatsoever to the utility grounded conductor would be a case where the risks probably are greatly diminished, but such an installation should still be constructed the same way even if not powered from the utility, most of the voltage issues that are present if we don't install proper EPB come from the fact we have a difference of potential at the load end of a grounded current carrying conductor than we have at the supply end, and though equipment grounding and bonding conductors don't carry current they are still bonded to the current carrying grounded conductor back at the service and this potential will still show up at remote locations.

Then consider you are also bonded to the POCO distribution grounded neutral, any voltage drop on that is also present between your system equipment grounds and bonding conductors and true earth. This is where the voltage often comes from when you hear of people getting electrocuted at boat docks with a boat lift yet nothing appears to be wrong with anything, if it were possible to put an EPG in the lake in those instances then those accidents likely don't happen.

Yep still trying to understand this a bit....

If God (or nature) makes a hole and fills it with water, theres no epg necessary.
If Man makes a hole and fills it with water, a epg is necessary.


OK ???

I understand this to a point.
It makes sense to me that if the utility companies turned off the switch we could all swim in peace..... :D
But if we run power to something at that body of water we have complicated things, now we at least need to decide if 680 or 682 applies.

As far as the POCO turning off the switch - they need to disconnect the grounded conductor as well, problems with ungrounded conductors is usually because of defective equipment, all other problems with stray voltages are because of potential differences between true earth and grounded/grounding conductors.
 

ritelec

Senior Member
Location
Jersey
Thank you

But if we run power to something at that body of water we have complicated things, now we at least need to decide if 680 or 682 applies.

No power to the body of water your at, should be no problem..

How far is this rule?


Hypothetically, there's a guy next to me who installs a swimming pool.
He's 20 ' or 30 ' or 60' away from my natural water hole or pond.. any problems in my watering hole?

I've been reading and as you mentioned, when we run power... I thought part of this had to do with the utility neutral/ground.

If there was a pool installed with no electrical equipment installed... would there still be a need for a epb...

(I know something would be needed for circulation.. but lets say there was running water you could direct or you had the professor fro gilligans island that figured something out.)
 

Dennis Alwon

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Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
I doubt the neighbors pool would be an issue at your pond. The equipotential bonding is to take care of stray voltages from underground lines so I don't see the pool as an issue.
 

kwired

Electron manager
Location
NE Nebraska
Thank you



No power to the body of water your at, should be no problem..

How far is this rule?


Hypothetically, there's a guy next to me who installs a swimming pool.
He's 20 ' or 30 ' or 60' away from my natural water hole or pond.. any problems in my watering hole?

I've been reading and as you mentioned, when we run power... I thought part of this had to do with the utility neutral/ground.

If there was a pool installed with no electrical equipment installed... would there still be a need for a epb...

(I know something would be needed for circulation.. but lets say there was running water you could direct or you had the professor fro gilligans island that figured something out.)
Doesn't matter if the neighbor builds a pool or a high rise hotel bringing something with elevated voltage to ground in close proximity to your watering hole is what would increase the electric shock risks at your water hole, installing a bonding grid is what makes it safer. Again you are not exactly "grounding" those items you are "bonding" them all together so that there is no potential between them. Though they are in general near earth potential you kind of don't care what potential they are to earth as long as there is nothing with any potential within reach of a user.

If constructing a pool with no electrical equipment I would still want to bond things together as it doesn't really take that much extra effort, and someday maybe there is electrical equipment.
 

GoldDigger

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Placerville, CA, USA
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On the other hand rivers streams and lakes seem to have been relatively safe as long as humans refrain from dangling wires into them.

Tapatalk!
 

kwired

Electron manager
Location
NE Nebraska
On the other hand rivers streams and lakes seem to have been relatively safe as long as humans refrain from dangling wires into them.

Tapatalk!
Not true, the boat docks and marinas are more of a hazard then a swimming pool with proper equipotential bonding. There have been many electrocutions from elevated voltage on the EGC to a boat hoist or some similar situation, well I guess you did say as long as humans refrain from dangling wires into them, should maybe even say from dangling wires within reach of someone in the body of water.
 

augie47

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Location
Tennessee
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State Electrical Inspector (Retired)
I think it is more than making a hole-- I believe throwing in the pumps changes it a bit-- a pond with no circulating pump would be fine but ....

Of course if this stuff is listed as natural pools then that would make it a pool but I think it is just a rubber membrane so you call it what you like...
IN a nutshell, that's my thinking.
 

kwired

Electron manager
Location
NE Nebraska
I think it is more than making a hole-- I believe throwing in the pumps changes it a bit-- a pond with no circulating pump would be fine but ....

Of course if this stuff is listed as natural pools then that would make it a pool but I think it is just a rubber membrane so you call it what you like...
I see some contradictions with "listed as natural"
 

Dennis Alwon

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Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
I am not certain they are listed at all with UL as this is just a membrane but they are sold as pools- call them natural or whatever they appear to be pools.

I have seen lake and ponds with pumps in the water used for aeration or to use water from the lake itself for irrigation. These are used to swim in and as Kwired mention there are many casualties around natural bodies of water.

If the army corp of engineers builds a lake is it a natural body of water? :D Rhetorical question
 

kwired

Electron manager
Location
NE Nebraska
I am not certain they are listed at all with UL as this is just a membrane but they are sold as pools- call them natural or whatever they appear to be pools.

I have seen lake and ponds with pumps in the water used for aeration or to use water from the lake itself for irrigation. These are used to swim in and as Kwired mention there are many casualties around natural bodies of water.

If the army corp of engineers builds a lake is it a natural body of water? :D Rhetorical question

I will try to give a rhetorical reply :D

Look at Lake Oahe located on the Missouri river, the dam that created this reservoir is in central South Dakota and the upper end of the reservoir is in North Dakota, it is roughly 230 miles long and has around 2250 miles of shoreline, try building an equipotential bonding plane for that:cool:

Lake Mead is the largest such reservoir in the US, but Oahe is much closer to me and I am familiar with it is why I gave it some mention.
 

RichB

Senior Member
Location
Tacoma, Wa
Occupation
Electrician/Electrical Inspector
Even after reading all these I am still torn--If I have a pond on my property and use it for swimming do I need to ground/bond it--the "pond" in question has been there for 40 plus years and used to serve as an irrigation water storage pond-- now I just Swim in it--or--If I dig a big hole and make one then do I ground--also--which is it 1.0 meters or 42 inches 1 meter equals 39 inches
Permanently Installed Swimming, Wading, Immersion,
and Therapeutic Pools. Those that are constructed in the
ground or partially in the ground, and all others capable of
holding water in a depth greater than 1.0 m (42 in.), and all
pools installed inside of a building, regardless of water depth,
whether or not served by electrical circuits of any nature.
 

Dennis Alwon

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Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Even after reading all these I am still torn--If I have a pond on my property and use it for swimming do I need to ground/bond it--the "pond" in question has been there for 40 plus years and used to serve as an irrigation water storage pond-- now I just Swim in it--or--If I dig a big hole and make one then do I ground--also--which is it 1.0 meters or 42 inches 1 meter equals 39 inches
Permanently Installed Swimming, Wading, Immersion,
and Therapeutic Pools. Those that are constructed in the
ground or partially in the ground, and all others capable of
holding water in a depth greater than 1.0 m (42 in.), and all
pools installed inside of a building, regardless of water depth,
whether or not served by electrical circuits of any nature.


All in ground or partially in ground pools, and any pool that holds water greater than 42" need a equipotential bonding. So a 3' deep in ground pool would need equipotential bonding. An above ground pool where the max water level is 42" or less does not need one-- not sure why not but it doesn't.

A pond with no pumps is fine but the addition of circulation seems to be the key- This is the point of the thread since it is not clear when the pond becomes a pool. I guess it is always best to use an equipotential bonding but it is not very practical esp in cases such as kwired mentioned.

It sounds like in your case there is no need for an epb
 
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