Another TIA for Perimeter Bonding

[petersonra]

Why is it that an above ground pool is less dangerous than an inground pool?

It seems to me that allowing anything other than steel reinforced concrete allows for a higher risk. Why not just require some kind of conductive deck around the pool?

 

[retirede]

2. Drownings: From what I have read, it always was with power on, except for marinas.

Maybe because the power is always on. The only time a pool doesn’t have power is during a power outage or when winterized.

 

[don_resqcapt19]

How about a NEC 2026 requirement that all in ground pools must disconnect all power to pools before use ?

It might not make any difference...many of the issues with the shock hazard at pools comes from an elevated neutral to earth voltage. This voltage drop on the utility primary and secondary neutrals and cannot be eliminated. There is always some voltage drop on any conductor that carries current. That voltage is on everything connected to the electrical bonding and grounding system. The pool bonding grid is connected to the service neutral via the equipment grounding conductors for any electrically operated pool equipment. This voltage is there even with your service main turned off. The shock hazard would still exist between any parts that are bonding and anything that is not bonded.

The real answer would be to prohibit any possible connection between the pool and the electrical system and still require the conductive parts of the pool to be bonded together. This, of course, would be very difficult and require major changes in pool and pool equipment design. Things like only fiber optic lighting in the pool with the fiber light source at least 10' from the pool, double insulated pool pumps with a non-conductive pump shaft, impeller and housing.

 

[petersonra]

Another option would be to ban the use of plastic pipe in favor of metallic pipe that would then have to be bonded.

I like the idea of no electricity in the pool area.

But as Don mentioned, it does not solve the whole problem.

Maybe some kind of monitor to check for unwanted voltage?

 

[mtnelect]

It might not make any difference...many of the issues with the shock hazard at pools comes from an elevated neutral to earth voltage. This voltage drop on the utility primary and secondary neutrals and cannot be eliminated. There is always some voltage drop on any conductor that carries current. That voltage is on everything connected to the electrical bonding and grounding system. The pool bonding grid is connected to the service neutral via the equipment grounding conductors for any electrically operated pool equipment. This voltage is there even with your service main turned off. The shock hazard would still exist between any parts that are bonding and anything that is not bonded.

The real answer would be to prohibit any possible connection between the pool and the electrical system and still require the conductive parts of the pool to be bonded together. This, of course, would be very difficult and require major changes in pool and pool equipment design. Things like only fiber optic lighting in the pool with the fiber light source at least 10' from the pool, double insulated pool pumps with a non-conductive pump shaft, impeller and housing.

That kind of leads me to the proposition of requiring the utilities to provide an insulated neutral instead of using the uninsulated guywire. It will cost extra for the utilities but will provide the safety that is missing.

 

[petersonra]

That kind of leads me to the proposition of requiring the utilities to provide an insulated neutral instead of using the uninsulated guywire. It will cost extra for the utilities but will provide the safety that is missing.

The NEC does not have any say over those conductors. As a practical matter, who would be paying for the many billions of dollars it would cost to replace all those conductors? pool owners?

 

[mtnelect]

The NEC does not have any say over those conductors. As a practical matter, who would be paying for the many billions of dollars it would cost to replace all those conductors? pool owners?

A Class Action Lawsuit would probably be a starting point to explain how many people have been electrocuted in swimming pools.

 

[retirede]

A Class Action Lawsuit would probably be a starting point to explain how many people have been electrocuted in swimming pools.

If you drive 10 miles to swim in your friends pool, chances are far greater you’ll be killed in a car wreck before being electrocuted in his pool.

33 people died of electrocution in pools between 2002 and 2016. About 2 per year. Between 35 and 40 thousand die in automobile accidents every year.

 

[mtnelect]

If you drive 10 miles to swim in your friends pool, chances are far greater you’ll be killed in a car wreck before being electrocuted in his pool.

33 people died of electrocution in pools between 2002 and 2016. About 2 per year. Between 35 and 40 thousand die in automobile accidents every year.

The possible Class Action lawsuit is for the Utilities not the NEC. The utilities are at fault for combining the neutral to the guy wire at the pole, the neutral should be insulated and separated. The swimming pool electrocutions could be the fault of the utilities trying to save money over lives.

 

[retirede]

The possible Class Action lawsuit is for the Utilities not the NEC. The utilities are at fault for combining the neutral to the guy wire at the pole, the neutral should be insulated and separated. The swimming pool electrocutions could be the fault of the utilities trying to save money over lives.

Good luck with that!

 

[petersonra]

The possible Class Action lawsuit is for the Utilities not the NEC. The utilities are at fault for combining the neutral to the guy wire at the pole, the neutral should be insulated and separated. The swimming pool electrocutions could be the fault of the utilities trying to save money over lives.

what difference would it make if they insulated the neutral? It would still be connected to earth.

 

[mtnelect]

Attached is the first three pages of "Multi Grounded Neutral"

 

[petersonra]

Attached is the first three pages of "Multi Grounded Neutral"

Again I ask what difference does it make? This is the neutral. There isn't going to be a whole lot of current in the neutral so there isn't going to be very much in the way of voltage drop if I remember correctly the neutral is grounded every two poles which is a couple hundred feet? So the worst case is you get whatever the unbalanced current is for 200 ft as the voltage drop.

You want to reduce the voltage drop cheap, you could ground it at every pole instead of every other pole near pools.

 

[mtnelect]

Again I ask what difference does it make? This is the neutral. There isn't going to be a whole lot of current in the neutral so there isn't going to be very much in the way of voltage drop if I remember correctly the neutral is grounded every two poles which is a couple hundred feet? So the worst case is you get whatever the unbalanced current is for 200 ft as the voltage drop.

You want to reduce the voltage drop cheap, you could ground it at every pole instead of every other pole near pools.

Thank you for taking the time to read part of the report.
Seems, like you do understand that the earth is being used as a "false" return to save the utility money.

 

[retirede]

Thank you for taking the time to read part of the report.
Seems, like you do understand that the earth is being used as a "false" return to save the utility money.

The utility runs all conductors needed to carry the loads served. The fact that one conductor is grounded in multiple locations doesn’t mean that the utility is using an earth return to “save money.” You’re really stretching things.

 

[petersonra]

Thank you for taking the time to read part of the report.
Seems, like you do understand that the earth is being used as a "false" return to save the utility money.

What is a false return?

All the current that goes out returns back to the source. A tiny amount of it returns through the earth. So what? That doesn't prove that it's dangerous.

 

[don_resqcapt19]

That kind of leads me to the proposition of requiring the utilities to provide an insulated neutral instead of using the uninsulated guywire. It will cost extra for the utilities but will provide the safety that is missing.

That would not change anything without eliminating the primary to secondary neutral bond at the utility transformer, requiring an supply side bonding jumper to be installed along with the ungrounded and grounded conductors to the service equipment, and you would also have to prohibit the bonding of the grounded conductor at the service equipment.

As far as things being the utilities fault, you might have go after the IEEE instead of the utilities. They publish the National Electrical Safety Code, which governs the utility installations, and the current installations are in compliance with that code. Following recognized standard for the current wring practices would be a very good defense from any suit over this issue.

 

[don_resqcapt19]

Again I ask what difference does it make? This is the neutral. There isn't going to be a whole lot of current in the neutral so there isn't going to be very much in the way of voltage drop if I remember correctly the neutral is grounded every two poles which is a couple hundred feet? So the worst case is you get whatever the unbalanced current is for 200 ft as the voltage drop.

You want to reduce the voltage drop cheap, you could ground it at every pole instead of every other pole near pools.

That is not completely correct. The only thing that the multiple grounding points on the primary neutral does is to provide additional conductive paths for the grounded conductor current, reducing the voltage drop. The connection to earth really does not reduce that voltage drop very much as the connection to earth has a very high resistance as compared to the resistance of the actual conductor.

The easiest way to get rid of this issue would by using transformers that have line to line connections, not the more typically line to neutral connections that are used for most single phase services....here again it is a cost issue that would require more expensive transformers, and additional costs to install a distribution system that has at least two ungrounded primary conductors at each single phase transformer.

 

[mtnelect]

That would not change anything without eliminating the primary to secondary neutral bond at the utility transformer, requiring an supply side bonding jumper to be installed along with the ungrounded and grounded conductors to the service equipment, and you would also have to prohibit the bonding of the grounded conductor at the service equipment.

As far as things being the utilities fault, you might have go after the IEEE instead of the utilities. They publish the National Electrical Safety Code, which governs the utility installations, and the current installations are in compliance with that code. Following recognized standard for the current wring practices would be a very good defense from any suit over this issue.

You are definitely a detail-oriented type person and have always respected your comments on this forum.

I had no idea that there was a connection between the IEEE & NEC.

 

[petersonra]

That is not completely correct. The only thing that the multiple grounding points on the primary neutral does is to provide additional conductive paths for the grounded conductor current, reducing the voltage drop. The connection to earth really does not reduce that voltage drop very much as the connection to earth has a very high resistance as compared to the resistance of the actual conductor.

The easiest way to get rid of this issue would by using transformers that have line to line connections, not the more typically line to neutral connections that are used for most single phase services....here again it is a cost issue that would require more expensive transformers, and additional costs to install a distribution system that has at least two ungrounded primary conductors at each single phase transformer.

It seems to me that your voltage drop between grounded points on the N is E=IR. So if you cut the length of conductor in half between grounded points the voltage drop between those points is cut in half. There is not a lot of current flow through the earth but whatever flow there is would tend to reduce the voltage drop between points where it is grounded.