fundamental electricity question

[junkhound]

I was designing power system wiring for Minuteman silo upgrades at the same time I built the house (early 1970s), so was thinking I'd try to get the house ground low enough so that EMP would not fry any of the wiring hmy: .
Still to0 high though, not nearly the same ground as a 12 ft diameter steel tube 80 feet deep.

 

[Ingenieur]

Ufer grounds are based on the "parallel" principle. The ft^2 area of the slab in contact with the earth basically makes many parallel grounds; as well as the "always moist" aspect of concrete. (Herbert G. Ufer created his namesake to ground ammunition bunkers in the Southwest against lightning strikes.)

POCO does the same thing. Multiground Neutral has in effect thousands of parallel grounds per mi^2 of service area. Your Ufer/rod/pipe is part of the big picture.

As for SWER, the HVDC Pacific Intertie has a large ground at each end, even though it's {?now} balanced. Good place to dump faults when required.

https://en.wikipedia.org/wiki/Pacific_DC_Intertie

The grounding system at Celilo consists of 1,067 cast iron anodes buried in a two-foot trench of petroleum coke, which behaves as an electrode, arranged in a ring of 2.02 mi (3,250.87 m) circumference at Rice Flats (near Rice, Oregon), which is 6.6 mi (10.6 km) SSE of Celilo. It is connected to the converter station by two aerial 644 mm2 ACSR (aluminum conductor, steel reinforced) conductors, which end at a "dead-end" tower situated at 45.497586°N 121.064620°W.

&

The Sylmar grounding system is a line of 24 silicon-iron alloy electrodes submerged in the Pacific Ocean at Will Rogers State Beach[4] suspended in concrete enclosures about one meter above the ocean floor. The grounding array, which is 30 mi (48 km) from the converter station and is connected by a pair of 644 mm2 ACSR conductors, which are in the sections north of Kenter Canyon Terminal Tower at 34°04′04.99″N 118°29′18.5″W installed instead of the ground conductors on the pylons. It runs from Kenter Canyon Terminal Tower, via DWP Receiving Station U (Tarzana; a former switching station), Receiving Station J (Northridge) and Receiving Station Rinaldi (also a former switching station) to Sylmar Converter Station. On the section between Receiving Stations J and Rinaldi, one of the two shielding conductors on each of two parallel-running 230 kV transmission lines is used as electrode line conductor.

ac-dc end the gnd is tied to the common point of the converter
for stability and to ensure each bipolar mag is equal

dc-ac end neut/gnd of inverter to establish the 0 crossing reference so the rms pos/neg swings are equal

they also provide a fault path for a downed dc line
Also the earth coupling provides for a common reference
likely carries sny minor imbalances too?

pics give general concept

 

[KundaliniZero]

Yesterday i had the same question.

I had read in books that in my country in rural areas we did that system because we have not to much money to distribute electricity to people in non urban areas. So it is a cheap system to get electricity to houses (eight (8) houses could be get light...but they are only rumors related with the picture)

But I have never seen the system work until yesterday.

The picture it is a transformer touching the wire of phase. At left 12kv and at right 220v because only one house it is on the right at 100 meters I think. The wire of phase it is making distribution in 12 kV (usual in my country) and then transforming at 220 v.

Enviado desde mi TA-1039 mediante Tapatalk

 

[ggunn]

Yesterday i had the same question.

I had read in books that in my country in rural areas we did that system because we have not to much money to distribute electricity to people in non urban areas. So it is a cheap system to get electricity to houses (eight (8) houses could be get light...but they are only rumors related with the picture)

But I have never seen the system work until yesterday.

The picture it is a transformer touching the wire of phase. At left 12kv and at right 220v because only one house it is on the right at 100 meters I think. The wire of phase it is making distribution in 12 kV (usual in my country) and then transforming at 220 v.

Enviado desde mi TA-1039 mediante Tapatalk

I have seen this in rural Texas as well.

 

[junkhound]

1871 telegraph grounding.

 

[FionaZuppa]

i read the the 1st few posts of the thread.

the earth as a conductor? is the Q.

interesting, because that is what Tesla was doing to "commercialize" power and/or signal delivery while experimenting in his lab out on LI NY.

the concept is to create a standing wave in the earths crust to be tapped into at some distance away. unfortunately for Tesla, JP Morgan halted funding as he learned that Tesla was promoting the technology as "free" power, which does no bode well with investors, etc.

for poco stuff, look at it the other way, if using earth ground

was a good way then poco would be saving lots of $$ not running extra wire.

but to appease the OP's Q, in some areas where just a "few" feet down you hit wet soil, that usually makes for a good conductor, its just not practical in application for a poco though because of the huge variance is soil.

 

[joebanana]

I know they combine in parallel. My point is, if 1 rod's contact resistance is significantly more than 50 ohms (such as 100 ohms), and 25 ohms are required, why do we get to follow the "two and done" rule? I would think we'd have to continue driving rods, until the total resistance is less than the requisite 25 Ohms. Or use another electrode.

Because 100 ohms combined in parallel with another 100 ohms, IS NOT 25 ohms.

Pour a copper sulfate solution on the rod.

 

[Carultch]

Pour a copper sulfate solution on the rod.

I was not aware of that solution, no punn intended.


But you are still missing the point of my question.

 

[ggunn]

Pour a copper sulfate solution on the rod.

Copper Sulfate is very toxic. Anything poured on the ground especially if it is water soluble eventually makes its way into the drinking water supply.

 

[Sahib]

Copper Sulfate is very toxic. Anything poured on the ground especially if it is water soluble eventually makes its way into the drinking water supply.

Any law against doing it?

 

[Coppersmith]

Copper Sulfate is very toxic. Anything poured on the ground especially if it is water soluble eventually makes its way into the drinking water supply.

Any law against doing it?

I guess basic morality is not a law so go ahead, poison the drinking water.

 

[MAC702]

Toxicity is relative to MANY things that are not being mentioned.