Electricity and electric and magnetic fields (EMFs)

Take a couple of fluorescent bulbs and walk under a high voltage power line and watch them glow, then put one end in the ground and watch them really light up. Get really brave and walk barefoot under the line and see your hair stand straight up Things my brother and I did when we were young and dumb. :)

Depending on soil characteristics, it isn't unusual to run local single phase high voltage distribution (4.8KV & 12.4KV, etc) with only one wire & using the earth for the neutral/return. Looks a bit strange to see only one wire at the top of the power pole.

I have often wondered about whether or not 3 phase Electric Fields would cancel out. Appears not to be the case.

3 Phase Electric Fields

The monitoring and control rooms are basically insulated to prevent electrostatic build up. With av pacemaker today I wouldn't get within a mile of the place.

Neat stuff, had no idea DC transmission has been around since the 1970s..
So I do have some knowledge of the Magnetic Field around a DC circuit.
BUT, nothing about a DC Electric Field, or so I thought....
Then Dr Google says this:
"DC Electric Field: DC Electric Fields, can be referred to as an Electrostatic Charge present on an object"
Now that I understand.

I had totally forgotten about the DC intertie. There's a wikipedia article, and sure enough, it has a picture of a tower with two big insulators.
https://en.wikipedia.org/wiki/Pacific_DC_Intertie

Mex!!!! Very interesting, thanks for sharing. I will be thinking about DC transmission advantages for a very long time.

It's the Path 4, West Coast intertie line. Washington state to Reseda CA. 3.5 gigawatts capacity. Direct current system. Not A.C.

It's 1 megavolts 1,000,000 volts direct current. The 10 meter distance, length of the insulators, is a clue.

The two wires are the same polarity.

in a ditch adjacent to the towers is the negative pathway. It is filled with conductive media. I was invited to a field survey in Ely Nevada that discussed basic soil composition and conductance to minimize earth eddy currents. Eastern Nevada was chosen over the alternatives because of that reason. I was a guest of Siemens.

Software controlled conversion and reversion of DC. Components are giga size with appropriate cooling air temperatures, moisture and contaminate containment.

An interesting study. The science behind it is in another dimension. This is PhD territory beyond my capabilities when I attended and now outside my area of interest. Power generation and storage is quite enough for me these days :)

Software controlled rectification using ultra low forward voltage drop interests me. As does artificial EMP and solar EMP. If alternator rectification involved .002 vf you cannot imagine the advantages. And it implies direct interface with camping and RV'ing. :)

"In the last diagram, which wire is a neutral and what is the voltage?"

I'll byte:

The neutral is the "stringer" and the voltage to Earth is 0 VAC at the Neutral Earth bonding point.
The bonding neutral (stringer) to Earth is in the breaker panel.

Note: "stringer" being the bare conductor cable physically supporting the L1 and L2 conductors.

JaxDad wrote:
A farmer near here got pinched by the nice folks at our electrical utility a while back.

He had a very well lit barn and storage / shop building for his side business.

Then we had a power failure.......

When the linesmen went past they thought it odd that his outbuildings were well lit but not his house or anything else.

Then it dawned on them, there was a 500 KV transmission corridor running across his pasture.

When they discovered he ha buried a huge loop of wire zig-zagging back & forth beneath the transmission lines they handed hm a huge bill based on what they 'estimated' his consumption had been.

So much for 'free' electricity.......

This is a great story to tell because it is a head scratcher. So was it via inductance to the Magnetic Field or capacitance to the Electric Field. Unquestionably it was the latter and here is why:

The power line was severed downstream of the farm so there would be no current flowing (so no Magnetic Field) BUT the upstream portion over the farm was still powered up. So we have a full blown Electric Field over the farmers "capacitance plate" in the field.

A single conductor from the capacitance plate to the primary of his transformer and the bottom of the primary to a ground rod in Earth.

;) ;) :)

On second thought, the towers were on line but the local distribution was down So, it could have been inductance to the Magnetic Field. My bad.