*Shallow end, being shocked when grabbing railing*

NowintersinAZ

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Oct 18, 2020
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Mesa, AZ
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If it is coming in on the neutral, what are the possible causes and fixes?
Possible causes are anything that chops up the sign wave to convert the incoming voltage to something else that it needs to run the equipment. i.e. computers, fluorescent lighting with electronic ballasts, TVs, things like that. There are filters that can be placed on the main panel that will filter out transients that are coming in on the service.

Does the way they distribute the three phases contribute to the issue?
It's not so much the distribution and more the loads. 3 phase is more susceptible to harmonics because they are 3phases at a 120 degree between hot conductors. It's exacerbated by the sharing of neutrals which is common in three phase system supplying 120v loads. Such as in an office building when supplying power to a floor full of cubicles. (cube farm)

In his case he does not have 3 phase and hopefully not sharing neutrals. I also believe the lines supplying the transformer supplying his house is also single phase. But he does have electronic loads which will muck up his electricity.

IF it is coming in on the service turning off the main breaker, can if ALL other power sources in the house are off or disconnected from the system i.e. solar panel, power backups, anything that will power up when the incoming power is lost. Can tell you it's riding on the incoming neutral. That's why I ask if it is lifted not during a power outage as state because the source of the transients could also have lost power.

And he could have a neutral in the house somewhere pressing against a grounded metal of a box or an EGC and leaking a bit to the EGC. That's why I asked if the main breaker from the service to the house is what was referenced in my last message. As that would eliminate the stray voltage he is seeing at the pool.

He stated that his panels are back to back. I wish I could see the setup as some people say back to back but there is a wall between them as in the meter is outside and the panel inside the house. if that is the case and the nipple between them is plastic and there are no screws shared by the meter and panel then turning off the main in the house and lifting the neutral in the panel would work and would not have to involve the power company. AGAIN safety first if someone is not comfortable ina panel they should call someone who is licensed and is. Always turn off power before lifting wires, as if there are shared neutrals you can and will burn up equipment.
 
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JamesW

TFP Expert
Mar 2, 2011
25,709
In his case he does not have 3 phase and hopefully not sharing neutrals.
I was thinking that maybe three phase was being split between different transformers where one phase went to one transformer and a different phase was sent to a nearby transformer?

If the power is not balanced, it might cause problems.
 
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NowintersinAZ

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Oct 18, 2020
87
Mesa, AZ
Pool Size
7560
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Intex Krystal Clear
I was thinking that maybe three phase was being split between different transformers where one phase went to one transformer and a different phase was sent to a nearby transformer?

If the power is not balanced, it might cause problems.
That could be I am not a lineman and have not studied power distribution.

An imbalance would not cause transients and in a properly configured circuit the neutral will only carry the unbalanced load. i.e. phase A has 10 amps, phase B has 15, the neutral will have 5 amps on it. Assuming we are talking about a 120/240 circuit that is sharing a neutral.

If all wires are hots 240 volt loads then there is no imbalance and the hots just share the loads. Or in the case of the power companies lines it could be 480 volts, or something higher depending on the area.
 
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JamesW

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Mar 2, 2011
25,709
The main power is 3 phase and single phases are pulled from the three phase distribution network.

If the loads are not balanced between all three phases, voltages can build up on the neutrals.

 

NowintersinAZ

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Oct 18, 2020
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Mesa, AZ
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Salt Water Generator
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Intex Krystal Clear
The main power is 3 phase and single phases are pulled from the three phase distribution network.

If the loads are not balanced between all three phases, voltages can build up on the neutrals.

As I said I am not a lineman and have not studied power distribution.

Power companies do not run neutrals in the grid. They are derived at the transformer feeding a business or house.

And as I stated and he confirms that the problem will manifest itself in circuits with neutrals. Here is another point to look at if his run to the pool is long the copper wires will act as a resistive load and you can get a voltage between the neutral and the EGC. This can be eliminated or reduce to with in code of a total of 5% for service drop and circuit length in the residence by running a bigger wire.

Yes industry can and do cause imbalance on the grid cause single phase brown outs or even total brown outs. I used to work in an area where an business was required to call the power company before turn on their equipment, because it drew such a large load that it effected the area around it.

You can track this with a chart recorder or even a volt meter with a min max function. Although you will only be watch one phase with a digital meter unless it has the ability to monitor two hots or your have two meters.
 
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JamesW

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Mar 2, 2011
25,709
I am not a power distribution expert.

So, I am just speculating on the possible causes.

If you have three different single phase end customers being fed by separate phases of a three phase main supply, the load will virtually never be exactly balanced.

Each transformer is grounded at the neutral.

If the three phases have significantly different load characteristics, then the load might try to balance on the neutrals through the ground.

This might be something to ask the power company about.

There is going to be a lot that the power company knows that they don't want to talk about as it could cost them a lot of money to address any issues.
 

NowintersinAZ

Well-known member
Oct 18, 2020
87
Mesa, AZ
Pool Size
7560
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Intex Krystal Clear
I am not a power distribution expert.

So, I am just speculating on the possible causes.

If you have three different single phase end customers being fed by separate phases of a three phase main supply, the load will virtually never be exactly balanced.

Each transformer is grounded at the neutral.

If the three phases have significantly different load characteristics, then the load might try to balance on the neutrals through the ground.

This might be something to ask the power company about.

There is going to be a lot that the power company knows that they don't want to talk about as it could cost them a lot of money to address any issues.
Agree, I was just thinking about the imbalanced grid. And it wouldn't cause (now I am not genus) a reading on the 3rd harmonic. Unless the loads that caused the imbalance were of the type that would cause them. We need to keep in mind it was found on the third harmonic and the only thing that I know of right off is electronics.

It is easy figure it out as it only takes a voltage reading to know if there is an imbalance on the incoming lines.
 
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JamesW

TFP Expert
Mar 2, 2011
25,709
The oscilloscope did not show a 180 hz signal on any of the three readings, so it's difficult to know how important the original reading of 180 hz was.

The triangle shape is interesting and it might provide an important clue to a power company engineer.

The OP definitely needs to get a good engineer from the power company to get involved in figuring this out.

I would send these reading to the power company to see what they can tell you.

They will have to refer the readings to an engineer. Once the engineer gives their opinion, you will now have a good person to help you track this down to the source.

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NowintersinAZ

Well-known member
Oct 18, 2020
87
Mesa, AZ
Pool Size
7560
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Intex Krystal Clear
I watched a TV show about those guys and how one pinhole in the rubber suit and they are toast! No thanks I will pass :)
Once they attach the rod to the power line they are at the same potential and there is no way the electricity can harm them. Even at the voltages they work with which is up to 250,000 volts. You can't see the insulators in the picture but if you count them and multiple by 11,000 that is near the voltage of the power lines.
 

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