Fault in a home transferred to the grid

[Andpie]

Oh ,and Larry Fine also suggests POCO issue.

 

[LarryFine]

Question remains can the fault in one home be transmitted out onto the grid and affect other homes fed by the same pole mounted transformer in this situation?

Having read through the thread again, I'm tending to agree with the open-neutral theory. It sounds like the POCO is looking to pass the blame onto one of its customers; in this case, yours.

They're claiming that your fire happened first, and then caused a problem in the other homes. It's far more likely that their problem caused your fire as well as the other homes' damages.

What were those other damages, and are there any other signs of over-voltage in any homes?

 

[ptonsparky]

This is par. We all have opinions but only two have voted.

 

[herding_cats]

We call this the "ripple effect". When you cause disturbances within your home, the rest of the power grid will feel it. Usually this shows up as unstable voltage, or a disturbance in harmonics (harmonic distortion). Imagine a pond of water that is perfectly calm. You throw a rock about the size of a tennis ball in the center of the pond, creating waves. This represents fundamental current, fundamental waveform. Now throw another rock 1/3 the size in the pond off to the right of center, creating another set of waves. Now you have created harmonic distortion, away from the original fundamental waveform. If you could measure the difference between the first waveform, and the second, you would be calculating THD, or "total harmonic distortion".

 

[LarryFine]

Imagine a pond of water that is perfectly calm. You throw a rock about the size of a tennis ball in the center of the pond, creating waves.

 

[herding_cats]

??

 

[ptonsparky]

We call this the "ripple effect". When you cause disturbances within your home, the rest of the power grid will feel it. Usually this shows up as unstable voltage, or a disturbance in harmonics (harmonic distortion). Imagine a pond of water that is perfectly calm. You throw a rock about the size of a tennis ball in the center of the pond, creating waves. This represents fundamental current, fundamental waveform. Now throw another rock 1/3 the size in the pond off to the right of center, creating another set of waves. Now you have created harmonic distortion, away from the original fundamental waveform. If you could measure the difference between the first waveform, and the second, you would be calculating THD, or "total harmonic distortion".

I'm quite sure the disturbances in my home are not affecting yours in any way shape or form.

 

[herding_cats]

It’s subtle, but they do.

 

[ptonsparky]

It’s subtle, but they do.

Similar to the butterfly flapping it's wings in Brazil affecting our weather here.

 

[herding_cats]

There is a Dutch children's book that starts with a nail entering a horse's hoof, the nail not removed, that leads to the complete collapse of a nation by war, starvation.

Additionally, the smart people at UL did not force cell phone companies to use power factor correction on non-linear phone chargers/rectifiers, it would have collapsed the grid completely about 10 years ago.

It all matters in the end.

 

[LarryFine]

There is a Dutch children's book that starts with a nail entering a horse's hoof, the nail not removed, that leads to the complete collapse of a nation by war, starvation.

For Want of a Nail

For want of a nail the shoe was lost.
For want of a shoe the horse was lost.
For want of a horse the rider was lost.
For want of a rider the message was lost.
For want of a message the battle was lost.
For want of a battle the kingdom was lost.
And all for the want of a horseshoe nail.

Why do we say For want of a nail the kingdom was lost?

For want of a nail the kingdom was lost: The source of this phrase and how to use it.

www.bookbrowse.com

 

[readydave8]

This is par. We all have opinions but only two have voted.

I felt bad for my part in this so I just now voted

Since multiple selection is allowed, I voted Yes and also No

 

[Andpie]

Well thanks again for all the input. This is great. To answer the question - What were those other damages, and are there any other signs of over-voltage in any homes? - yes. The story goes that the house across the street from the house with the fire had a power failure at some point. It is not known if it was before during or after the fire. But too close to the time of the fire I.M.OP. to be a coincidence. Right there I'm thinking PO CO because I cant see one house taking out the other, but OK, and keep in mind that there are no adverse signs at the pole, service drop, weather head, meter pan, main load center - nothing - So we do know that the non fire house's whole house generator kicked on and was supplying power for a period of time. (More than 1 hour less than 8). An emergency service call was responded to and the electrician found the house dark. Troubleshooting he found a faulty oil pressure switch in the generator that shut down the generator operation and prevents the transfer switch from doing anything including switching back to utility power. (Another coincidence?) Electrician replaces the switch and finds that the utility power is live and restores power the the non fire house.
Also at some point PO CO comes out and severs the service drop to the fire house and claims that is all that they touched.
Inside the non fire house a rack mounted power supply (UPS) bit the dust (no smoke just not working) cant be sure if it was damaged as a result or not, and some new style Leviton Load center CB's had to be replaced. I am working on obtained the replaced items. I understand that some of these new beakers can't be reset and must be replaced. The replaced CB's are the new white color AFCI or combination AFCI/GFCI.
So now what do you guys think? I know need a better time line as things are sketchy.

 

[ptonsparky]

Which breakers can't be reset?

 

[Andpie]

Google Leviton new style load centers
They are white in color

 

[GoldDigger]

Ok well thank you everyone for that information. This is a great platform. When I said a “fault “ that was a very broad term. So that could cover just about everything.
So we know that the 220v / 240 v whatever the case may be is derived from the pole mounted transformer and we are not talking about a fault there. So correct me if I’m wrong but the voltage from the residence can never be more than it was supplied. That means we are talking about a fault current . In order to trip the network protection device on the primary side of the transformer the current would have to be extremely high. Agreed?
The service into the house looks unscathed. Main CB not tripped. Fire on the opposite side of the house from the service drop. So that means the fault was within a branch circuit. I’ll give you the benefit of doubt and say the fault occurred at an electric range on a 220v 50A CB. Question is - is that fault current enough to cause an issue at the neighbors house in anyway?

In theory, which is a large caveat, a bolted fault between one line conductor and the neutral could pull the neutral far enough away from its nominal voltage that devices driven between the other phase and neutral could see a damaging overvoltage condition.
However, I think it should not be possible for that overvoltage condition to reach a customer served by a separate service drop from the POCO secondary winding.

 

[LarryFine]

In theory, which is a large caveat, a bolted fault between one line conductor and the neutral could pull the neutral far enough away from its nominal voltage that devices driven between the other phase and neutral could see a damaging overvoltage condition.

At the customer's end of the service drop/lateral, and for a short (no pun intended) time, yes.

However, I think it should not be possible for that overvoltage condition to reach a customer served by a separate service drop from the POCO secondary winding.

Not without a defect of some kind (*cough* bad neutral *cough*) ahead of the dividing point.

 

[GoldDigger]

A serious problem with the vote just on the question asked in the first post, is that a "Yes" response could correspond to a "Yes, but it could not cause damage" opinion.

 

[Fred B]

Can an electrical fault in a residence be transferred out onto the service grid affecting other homes in the area on the same secondary side of the transformer?

It would require several extraordinary conditions to exist simultaneously for an occurrence to extend from one service into a separate service off the same xfer. As some suggested most likely would have to carry from something on the neutral.

Anything in residence in question that could create a very high frequency return that might be close to the level of a lightning strike?
Not aware of any equipment that is normal for residential use that could do that.

 

[Andpie]

Thank you again. Nope no lighting strikes recorded at all. Weather was good. I just cant get my head around an over voltage situation on one phase vs the other unless there was an issue with the neutral on the utility side of things. The loss of "balance" between phases at one house would not affect the other house because we have to "assume" that the second house is still viably connected to their neutral. Unless we are saying that a loss of neutral from POCO caused issues in both houses only the fire house had a device more susceptible to failure such as an old RPT with non fused MOV's or something of that nature. Well I think we beat this dead horse enough. I'm going back to the scene tomorrow and Ill give you guys an update if anything new is found. Again, I really appreciate the input. Stay safe out there.