Electricity leakage question?

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Old 07-03-17, 07:54 AM
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Electricity leakage question?

Hello, I discovered this weekend that I have a broken bond wire on the handrail anchors of my in-ground pool. I have a cut on my hand and when I grabbed the handle with my feet in the water I got a slight shock. I ran a temporary wire from the bonding loop to the hand rail and the shock did not exist. So now I have to figure out a way to install a new bonding wire to the anchor cast in concrete. The anchor is about 5 feet from the edge of the concrete so not sure if I can fish the wire under ground to the anchor, but I will figure something out. Once I diagnosed it to the be a bad bonding wire I started trying to figure out where the electrical leak is coming from. I finally killed all power to the house by tripping the main house breaker. My main breaker for the house is mounted directly beside the power meter. With everything off I am still getting the leak in the pool. Is it common for underground power to have a slight leak? If it's leaking before the meter, would it be the power companies responsibility to find and fix? Just looking for suggestions on what my next step should be? First thing is getting the bonding wire fixed!
 
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Old 07-03-17, 08:28 AM
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If it is leaking before the meter, how is it getting to your pool? Could the main breaker maybe leaking? Remove the cover & test it.
 
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Old 07-03-17, 08:37 AM
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The power is ran about 200 feet underground from the main transformer pole to my house meter. The main breaker is mounted in a box attached to the side of the meter box. So you do not think it can leak before the meter? Why not, just curious? I suppose the main breaker could be leaking but how can I test for that? Everything in the house and pool is dead when I flip the breaker.
 
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Old 07-03-17, 11:01 AM
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There is a three wire service feeding your home. Two hot legs and neutral. The ground for the house service comes from water service bonding and ground rods.

If you don't a have metal incoming water line then you only have a ground rod.

The ground also connects to the incoming neutral in the first panel which is usually the main breaker panel.

You are either missing the ground to your service or it is not effective enough.

You need to start by assessing how the service is grounded. If you aren't sure.... the help of an electrician would be warranted here.

Just to add..... this is an in ground pool. What is the construction ? Plaster, cement ?
There should be a bond system around the pool. The ladder, the filter, the pump, the light niche, etc. all connected together. That should also act as a service ground but apparently it is not. I would also have the pool bonding assessed.
 
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Old 07-03-17, 11:31 AM
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Thanks Pete. You are correct on the house incoming power and the grounding for the house is the grounding rod only. The water supply is PVC into the house.

The ground and neutral are connected properly in the first (main breaker) panel.

I plan to have the main panel replaced in the near future as it is old and is a six throw main breaker panel. It was installed when the house was built in 1980. I have only owned this house for 2 years and slowly updating things as I go. I want to have installed a main panel with a single throw main breaker. I will have the electrician access the grounding when the panel is replaced. Does that sound like a good plan? Maybe it is common practice for electricians to check that but I will point it out just in case.

This is an inground vinyl pool. I assume it has metal walls behind the liner. Everything is properly bonded except the hand rail at the stairs. This is the only metal item that appears to not be connected to the bonding grid.
 
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Old 07-03-17, 03:09 PM
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6 Throw Main Breaker Panel Help - Electrical - DIY Chatroom Home Improvement Forum

Is that your post? You didn't tell us that the box was outside & had rust in it. I would think that it could matter.
 
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Old 07-03-17, 09:53 PM
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That is my post. The sub panel has been replaced for the pool. Still looking into getting the main panel replaced. You think that could be the issue?
 
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Old 07-04-17, 06:07 AM
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Re-bond that handrail and other metal objects as soon as possible, even if you need to run a copper wire on the surface embedded in a thin berm of epoxy.

Bonding of the metal parts about a swimming pool is intended to get the voltage difference between these parts and the water and the concrete pool walls as small as possible.

The greater the voltage difference the greater the chance you can feel a shock.

A correctly wired house has ground rods and/or a metal cold water line underground all of which are bonded to the panel neutral. The mere presence of these buried objects (grounding electrodes) means that although most of the neutral current goes back to the pole transformer via the service drop neutral/ground/support wire, a minute amount gets back via the earth (ground*, dirt, soil).

... if there is leakage before the meter, how is it getting to the pool? ...
Pick a point, say, the neutral terminal of the pole transformer, and call that the zero voltage reference. Your house grounding electrode system, every neighbor's house grounding electrode system, and ground rods at some utility pole bases all result in minute currents flowing in various directions through the earth. At any given point on the earth such as under the middle of your pool, there is a voltage relative to the aforementioned reference. It would take many pages of text to predict and compute the voltage relative to reference at any given point on the landscape. Whenever there is a voltage difference (potential difference) between two objects, additional current, leakage if you insist, can flow given another conductive path such as a person between those objects tand that person touching both objects might feel a shock.

Concrete is slightly porous so it becoms a little moist inside. So current can leak through the pool walls and into the water and through you.

An equipotential grid (network of buried copper wires) under the pool deck helps drain (short circuit) any voltage difference in the earth to the ground wires of any electrical equipment, thus making any voltage difference smaller (or unmeasurable) and nearly eliminating any chance of electric shock.

Ground fault circuit interrupters affecting all power arriving at the pool including power for the pool filter pump will offer near perfect protection against electrocution even if bonding of railings and other metal parts is incomplete or defective. But a GFCI will not eliminate the possibility of feeling a shock.

* As in: (diner) "This coffee tastes like mud!" (waiter) Well, it was ground this morning.
 
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Old 07-04-17, 07:08 AM
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Thanks Allen. Getting the bonding fixed asap! Thanks for the explanation. That makes me feel better. Everything for the pool is on a GFCI breaker. I am double checking all other metal objects today to be sure they are correctly bonded.
 
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Old 07-05-17, 04:54 AM
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I'm only going to disagree with Allen's excellent explanation on one minor point: The purpose of the equipotential grid is not to drain or short circuit anything. The grid raises the voltage of the earth in the immediate vicinity, and that is what prevents you from feeling a slight shock.

As for where this voltage comes from (when your main breaker is off), it's due to losses in the power company neutral, and gets worse during high load situations... like during July in air conditioning territory. Even with 0 neighbors and a perfectly wired/grounded panel, you'd feel the shock still the same. Well as long as there was poco load on your run caused by somebody.

The voltage on the neutral (and all bonded equipment) _must_ be higher than earth ground when the poco neutral is carrying current. That is, until we start using lossless superconductors on the poles. (Not gonna happen.)

A fun way to measure this voltage difference as the weather (load) changes is to take a voltmeter and put one lead on something bonded to neutral accessible outside, like the copper wire going to your panel. Hook the other lead of the voltmeter to a screwdriver placed into the earth a good 6+ feet away. Watch the changes throughout the day and as the temperature changes if you're curious.

This voltage is not directly harmful, except for the drowning risk caused by a poor swimmer being startled and unable to get out of the pool each time he tries to do so. It can also cause livestock to refuse to drink their water depending on the watering setup. In fact I'd go so far as to say the average farmer/rancher is more acquainted with all of this than your average city electrician.
 
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Old 07-05-17, 07:34 AM
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Thanks Core! I will try that "science experiment" out.. My biggest concern was it getting worse and causing electrocution. From what I read it will only be a nuisance shock. I have a temporary wire ran to the handrail from the main bonding wire at my equipment pad and it eliminated the shock. I also bought an analog meter so I could check the ohm's and now everything is at zero. Thanks again for every ones help! Now I have to figure out how to get the bonding wire permanently connected to the hand rail anchor, under the concrete if at all possible.....
 
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Old 07-05-17, 10:52 AM
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The bond is to create the bird on a wire effect. If everything is at the same voltage there can be no shock hazard since there is no potential difference.
 
 

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