Ask me about industrial electricity 2: electric boogaloo

The Something Awful Forums > Discussion > Ask/Tell > Ask me about industrial electricity 2: electric boogaloo

randomidiot: May 12, 2006; by Fluffdaddy
(and can't post for 11 years!)

They won't glow super bright - that's a fairly long exposure that I found here - but they will definitely light up.

I used to live in an apartment that was nearly directly under some ~500kv lines (the poles were in the parking lot about 100 ft from my front door) - when I switched to CFLs all of my lights would (barely) glow all the time. It was kinda neat to hang out on the porch on a humid night with a beer and :2bong:

and listen to the lines crackling/see a bit of corona discharge around the insulators.

I haven't turned into a super human or been raped by cancer.. yet. :tinfoil:

I will admit I was always a little concerned that someone would nail one of the poles in the parking lot and cause some ugly stuff, despite the substantial concrete bases. I also always wondered how the gently caress code permitted any of that, though the place was built in the late 60s..

# ? Nov 14, 2012 10:00

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# ? May 10, 2024 06:28

grover: Jan 23, 2002; PEW PEW PEW

The Cleaner posted:

Holy.. crap.

So uh.. there is really nothing to those studies that show cancer rates living near power lines and such? That seems pretty crazy I kinda wanna try that though. Just bring a box of lightbulbs out there and see what happens.

There is a capacitive effect between the power lines and earth that creates an an electric field. Line the bulbs up in-line with the EMF field lines (notice the bulb on the ground is not lit), and it induces a small amount of current to flow within the gasses of the fluorescent bulb. You can actually find higher magnetic fields in your home, believe it or not, caused by some of your appliances. And yes, it's completely harmless to humans; many studies have been done, but there is no conclusive evidence of any risk to people.

http://www.cancer.gov/cancertopics/factsheet/Risk/magnetic-fields

# ? Nov 14, 2012 11:41

Not a Children: Oct 9, 2012; Don't need a holster if you never stop shooting.

Power lines do not cause cancer. Cell phone towers do not cause cancer. Wifi does not cause cancer. Same goes with headaches, nausea, Alzheimers, etc etc. Electrosensitivity is complete pseudoscience and anybody who is trying to convince you that your electricity is invisibly harming you is trying to sell you something.

# ? Nov 14, 2012 13:21

Simulated: Sep 28, 2001; Lowtax giveth, and Lowtax taketh away.; College Slice

edit: carry on.

Simulated fucked around with this message at 00:21 on Nov 15, 2012

# ? Nov 14, 2012 17:54

Frozen Horse: Aug 6, 2007; Just a humble wandering street philosopher.

The stress response to low socioeconomic status associated with neighbourhoods with lots of overhead power lines is associated with cancer. But tackling that that would involve problems that can't be solved by NIMBYism.

# ? Nov 14, 2012 17:56

peepsalot: Apr 24, 2007; ��PEEP THIS...
��BITCH!

There was a guy a while back that did a big art thing laying out 1300 flourescent light bulbs under a high power line:

"Field" by Richard Box

http://vimeo.com/11137816

# ? Nov 14, 2012 19:27

Three-Phase: Aug 5, 2006; by zen death robot

peepsalot posted:

There was a guy a while back that did a big art thing laying out 1300 flourescent light bulbs under a high power line:

"Field" by Richard Box

http://vimeo.com/11137816

The thing you have to remember with photographs is by adjusting the exposure you can make objects like that glow as brightly or dimly as you want them to.

some texas redneck posted:

They won't glow super bright - that's a fairly long exposure that I found here - but they will definitely light up.

E;F,B

Three-Phase fucked around with this message at 23:01 on Nov 14, 2012

# ? Nov 14, 2012 22:58

grover: Jan 23, 2002; PEW PEW PEW

Ender.uNF posted:

For the magnetic field part, we are living in a constant magnetic field given off by the earth.

As for electromagnetic waves, it's not magic. The waves do the same thing to whatever they hit: cause that thing to vibrate at the frequency of the wave. Different materials vibrate more easily at different frequencies. Lower frequencies, like radio, etc are so big (IIRC VHF is feet long) relative to the size of your cells that your body is essentially invisible to the wave... Kinda like how bass sound frequencies pass through walls and such, but high frequencies are more easily absorbed by the walls.

For microwaves, they are centimeter lengths so your body does absorb them and convert them to heat but the effect is so small and irrelevant that you need waves tuned specifically to the resonant frequency of water to have any effect (around 2.5 Ghz) and even then you need a *ton* of it. That's why microwave ovens are enclosed little boxes - to keep 1000 watts of microwaves bouncing around inside, otherwise the food would never heat up. If you opened the door and defeated the safety, you'd just feel a warming sensation, assuming you pressed right up on it. Cell phones emit milliwats by comparison and without trapping the waves in a tiny metal box where they bounce around and around until they eventually hit your body, so the effect is even smaller than the minuscule power levels would suggest.

And the warming sensation of a campfire? That's infrared radiation hitting your skin and warming it up. The exact same effect as microwaves. They are literally the same mechanism, photons traveling at the speed of light... It's just that most matter resonates at infrared frequencies much better than any others (and when it heats up, all matter gives off infrared frequencies... The atoms in the cells of your body are emitting electromagnetic radiation internally right now!)

Visible light? Same thing as those radio waves bringing you a TV signal. All just photons. It just so happens that proteins in your retina resonate at visible light frequencies very easily so they absorb the photons and trigger chemical reactions that result in vision.

Why are X-rays and gamma rays (even higher frequencies still) dangerous? Because those waves are the size of your cells or the DNA in your cells, so they cause the DNA to resonate, heat up, and break apart. The DNA damage is what causes cancer. Only rays small enough to cause that reasonance have any potential to cause cancer.

Oh, and we are constantly bombarded with radiation and particles from space, even while inside the womb, so you've never been free of these effects and neither were the Romans nor the first land walking animals. The total power output from all man-made sources of electromagnetic radiation are less than 1/10 of 1% of the radiation dose you'll get just from existing.

Did I mention that radon gas constantly escapes from the earth, throwing off nuclear fission products? Hope you don't have a basement! Live in Denver or take a plane flight? That's another huge dose of radiation.

Remember: it's not magic, it's just electromagnetic radiation.

That's great and all, but has nothing to do with what's lighting up fluorescent bulbs under power lines, which is caused by the electric field, not an electromagnetic wave. For example, 200kV lines 20 meters overhead will create an electric field strength of appx 100v/cm. This is well under the 33kV/cm dielectric breakdown strength of dry air so it doesn't arc, but because it's at 60Hz, it does create a strong capacitive effect that can induce current to flow through conductors. It's such a small amount of current that it's not normally noticeable, but even small amounts of current can make fluorescent bulbs glow.

grover fucked around with this message at 23:21 on Nov 14, 2012

# ? Nov 14, 2012 23:19

Three-Phase: Aug 5, 2006; by zen death robot

ABB's game-changing HVDC breaker.

:holymoley:

Just a stack of IGBTs and a mechanical breaker combined?

# ? Nov 17, 2012 15:29

silence_kit: Jul 14, 2011; by the sex ghost

grover posted:

That's great and all, but has nothing to do with what's lighting up fluorescent bulbs under power lines, which is caused by the electric field, not an electromagnetic wave. For example, 200kV lines 20 meters overhead will create an electric field strength of appx 100v/cm. This is well under the 33kV/cm dielectric breakdown strength of dry air so it doesn't arc, but because it's at 60Hz, it does create a strong capacitive effect that can induce current to flow through conductors. It's such a small amount of current that it's not normally noticeable, but even small amounts of current can make fluorescent bulbs glow.

This is such a minor point, but I'm bringing it up because you insisted on telling him that he was totally wrong. Electricity in a transmission line is totally an electromagnetic wave.

You are right in that he is putting on airs a little bit by talking about waves and especially photons when a fluorescent light bulb is so small compared to the wavelength at 60 Hz, but he isn't wrong.

silence_kit fucked around with this message at 23:40 on Nov 17, 2012

# ? Nov 17, 2012 16:26

Cheesemaster200: Feb 11, 2004; Guard of the Citadel

Three-Phase posted:

ABB's game-changing HVDC breaker.

Just a stack of IGBTs and a mechanical breaker combined?

This is going to be big for all those theoretical wind farms in the middle of nowhere or offshore.

# ? Nov 18, 2012 23:32

Three-Phase: Aug 5, 2006; by zen death robot

Cheesemaster200 posted:

This is going to be big for all those theoretical wind farms in the middle of nowhere or offshore.

Hush! Imagine the benefits of adding an extra 500 megawatts to the grid!
_{Not that much compared to other power plants.}

# ? Nov 19, 2012 00:21

Knitting Beetles: Feb 4, 2006; Fallen Rib

Three-Phase posted:

Hush! Imagine the benefits of adding an extra 500 megawatts to the grid!
_{Not that much compared to other power plants.}

At least it's operating at 17% efficiency!

Speaking of which: a 500 MW wind farm in the German North Sea has just been cancelled/postponed because the utility can't get its poo poo together with the HVDC converter stations. The idea was to build a big AC/DC platform, connect various wind farms at 150 kV (AC) and then send it to shore at DC.

Too bad really, I had a year and half of contract work lined up for that bad boy and now I'm scrambling to get some work after March next year.

# ? Nov 19, 2012 22:53

Three-Phase: Aug 5, 2006; by zen death robot

some texas redneck posted:

I used to live in an apartment that was nearly directly under some ~500kv lines (the poles were in the parking lot about 100 ft from my front door) - when I switched to CFLs all of my lights would (barely) glow all the time. It was kinda neat to hang out on the porch on a humid night with a beer and and listen to the lines crackling/see a bit of corona discharge around the insulators.

I have never actually seen corona discharge, but I've heard it walking underneath 345kV lines.

# ? Dec 14, 2012 01:36

SlayVus: Jul 10, 2009; Grimey Drawer

What are the giant spherical objects on the lines on poles? Would it there be a reason why they would keep them on the line for over two years?

# ? Dec 14, 2012 17:27

grover: Jan 23, 2002; PEW PEW PEW

SlayVus posted:

What are the giant spherical objects on the lines on poles? Would it there be a reason why they would keep them on the line for over two years?

If you're referring to what I believe you are, they're so aircraft can see the power lines are there.

# ? Dec 14, 2012 17:30

Sneaking Mission: Nov 11, 2008

That's what happens when kids play basketball around power lines. Make a slam just a little too hard and it hits the wire and fuses in place. They would have to shut down the juice to get them off and that's a hassle so they'll leave them up.

# ? Dec 14, 2012 17:31

SlayVus: Jul 10, 2009; Grimey Drawer

grover posted:

If you're referring to what I believe you are, they're so aircraft can see the power lines are there.

The lines are below the level of the tree line though and there used to be a four story hospital next to those lines until the hospital was destroyed by a tornado.

# ? Dec 14, 2012 17:33

grover: Jan 23, 2002; PEW PEW PEW

SlayVus posted:

The lines are below the level of the tree line though and there used to be a four story hospital next to those lines until the hospital was destroyed by a tornado.

Did that hospital have a helipad?

grover fucked around with this message at 17:37 on Dec 14, 2012

# ? Dec 14, 2012 17:34

SlayVus: Jul 10, 2009; Grimey Drawer

grover posted:

Did that hospital have a helipad?

Yes

It still doesn't make sense though.... even though you are correct it seems on your first statement. The lines are lower than the helipad would have been.

# ? Dec 14, 2012 17:34

grover: Jan 23, 2002; PEW PEW PEW

SlayVus posted:

Yes

It still doesn't make sense though.... even though you are correct it seems on your first statement. The lines are lower than the helipad would have been.

If the spheres look like this, it's for visibility, nothing more. Might also be for cranes or other personnel working in the area, as they're used for "HEY, THIS WIRE IS LIVE!" sometimes, too. In this case, it's most likely still just for safety's sake for the helicopters. It's just something that's standard when lines are near airports and helipads and other places pilots there's an increased risk of an aircraft collision.

# ? Dec 14, 2012 17:37

helno: Jun 19, 2003; hmm now were did I leave that plane

As a pilot who does a bit of low altitude flying I can assure you that power lines are loving invisible.

The lines might be lower than the treeline now but don't forget that trees grow and most power infrastructure is rather old.

# ? Dec 14, 2012 22:01

Three-Phase: Aug 5, 2006; by zen death robot

This is a video that mentions the markers.

https://www.youtube.com/watch?v=E-bU8dHwSFo&t=1080

There was also an electrocution in that video as well, 480V

https://www.youtube.com/watch?v=E-bU8dHwSFo&t=2075

Drawing maintenance is absolutely critical in electrical systems. It's easy to make changes ("The box was cramped so instead of running the cable to breaker 12 we ran it to breaker 16.") can result in disasters. (That and always using your Volt Alert or meter to check.)

I recently had a problem with a control circuit, and I found that a simple short-cut taken (ganging two wires on one contactor terminal instead of using separate, isolated terminals) created a sneak-circuit. That circuit caused a PLC to indicate that the system was in one state when it was really in another state. (To be fair, in my original design I made the same mistake until someone more experienced pointed it out.) I looked at the schematic and immediately realized what the electrician did, opened the box, and did see two wires on one terminal. I explained the error to them, and consoled them in the fact that I made that mistake too.

Three-Phase fucked around with this message at 13:26 on Dec 15, 2012

# ? Dec 15, 2012 13:12

Anti-Hero: Feb 26, 2004

That 480V electrocution video is why you should always meter a circuit even after you think it's isolated.

I also hate that the narrator said "440 volts of current passed through his body"...

# ? Dec 15, 2012 23:49

Three-Phase: Aug 5, 2006; by zen death robot

Anti-Hero posted:

I also hate that the narrator said "440 volts of current passed through his body"...

Yeah, that's up there with "Victim is recovering from his electrocution".

# ? Dec 16, 2012 13:35

virtual256: May 6, 2007

What are the common components of your average everyday city substation?

Also, what are the common components of the larger regional ones?

# ? Dec 26, 2012 10:58

Three-Phase: Aug 5, 2006; by zen death robot

virtual256 posted:

What are the common components of your average everyday city substation?

Also, what are the common components of the larger regional ones?

I have trouble differentiating between those two, but I'd say things like circuit breakers, isolators, capacitor banks, line reactors, transformers, and control houses.

# ? Dec 28, 2012 00:19

single-mode fiber: Dec 30, 2012

Three-Phase posted:

I have never actually seen corona discharge, but I've heard it walking underneath 345kV lines.

You should hear the Jackson Ferry-Wyoming interconnection some time. It's got 6 lines per phase, which is supposed to make it quieter, but, at 765 kV, the sound is impressive (and awesome).

# ? Jan 3, 2013 01:31

FrozenVent: May 1, 2009; The Boeing 737-200QC is the undisputed workhorse of the skies.

So this came up in the Bitcoin thread in GBS, I thought it was topical and should be cross-posted here:

TheColorBlue posted:

What is the likelihood that this monstrosity manifested out of buttcoin mining?

NOTE: This is a BIG image thus it may break tables once enlarged.

This is apparently a place of business, so... Can anybody here explain why, exactly, someone would want to cool down their breaker panel?

Edit: Woops, sorry.

FrozenVent fucked around with this message at 21:30 on Jan 7, 2013

# ? Jan 7, 2013 21:01

Noctone: Oct 25, 2005; XO til we overdose..

Umm that's a breaker panel, not a fuse box. And if I had to guess, I'd say that fan is some idiot's idea of moisture abatement.

# ? Jan 7, 2013 21:27

IOwnCalculus: Apr 2, 2003

I was thinking either they're running a circuit right at the ragged edge and are trying to cool the breaker down so it doesn't trip, or they've got a shoddy breaker that needs to be replaced because it heats up when it shouldn't.

Either one seems monumentally stupid to me.

# ? Jan 7, 2013 22:02

grover: Jan 23, 2002; PEW PEW PEW

FrozenVent posted:

So this came up in the Bitcoin thread in GBS, I thought it was topical and should be cross-posted here:

This is apparently a place of business, so... Can anybody here explain why, exactly, someone would want to cool down their breaker panel?

Edit: Woops, sorry.

Overloaded breakers get hot and trip. They do this to protect overloaded wires which also get hot and can burn buildings down when breakers don't trip and they get too hot.

I'm thinking someone reset a tripped breaker and noticed how hot the motherfucker was, but instead of fixing it, rigged up a fan. Stupid.

# ? Jan 7, 2013 22:14

Noctone: Oct 25, 2005; XO til we overdose..

Can't wait to read about that in the inevitable OSHA fat/cat report. :xd:

# ? Jan 7, 2013 22:38

Three-Phase: Aug 5, 2006; by zen death robot

I'm cooking up something special on electrical hazards. I want to make sure I haven't missed anything. Here's my list:

Electric shock
-Ohm's law and current effects
-GFCIs and other safety items
-Ungrounded/grounded systems (elevated voltage during a fault)

Electrical safety history
-Early systems and dangers
-"Mixed voltages" on overhead wires
-"Jones is dead!" (Square D) and knife switches
-Hazards in earlier systems (metal case connected to neutral, exposed machinery, moving machinery)

Arc flash
-Effects
-PPE (NFPA 70E)
-Reduction (fuses, trip settings, current limiting devices like reactors)

High voltage
-Voltage gradient on downed line
-Hopping/shuffling
-Rubber mat use, safety grounds, etc.
-System misconfiguration

Meter safety
-Meter category (I - IV)

System safety
-National electric code NFPA 70
-Electrical fires
-Generator backfeed

Am I missing anything good?

Three-Phase fucked around with this message at 12:45 on Jan 24, 2013

# ? Jan 24, 2013 12:43

Noctone: Oct 25, 2005; XO til we overdose..

Only thing that immediately comes to mind for me is arc flash boundaries. Perhaps ladders/lifts/scaffolds, too, w/r/t overhead lines.

# ? Jan 24, 2013 14:59

peepsalot: Apr 24, 2007; ��PEEP THIS...
��BITCH!

power suppply isolation, or is that part of grounded/ungrounded?

# ? Jan 24, 2013 18:25

Three-Phase: Aug 5, 2006; by zen death robot

peepsalot posted:

power suppply isolation, or is that part of grounded/ungrounded?

Could include that with grounding. One of the comments is about how on a delta system (like 480V) there's no such thing as true isolation, in fact the "line to earth" voltage is the same as line to line.

# ? Jan 25, 2013 02:23

Frozen Horse: Aug 6, 2007; Just a humble wandering street philosopher.

Stored energy in disconnected systems. This can range from the obvious such as batteries and capacitors, through subtle cases like rotational inertia of motor-generators, to weird stuff like superconducting solenoids.

Also, X-ray hazards from vacuum HV discharges.

# ? Jan 25, 2013 07:44

Three-Phase: Aug 5, 2006; by zen death robot

Stored energy - that's good too!

One additional thing I considered is "mission-critical" electricity where a supply or power quality problem could lead to death. Things like:

1. Life-support and medical systems at a hospital
2. Ventilation fans in a mine
3. Fire pumps
4. Military systems (melt before fail and battle short)

# ? Jan 25, 2013 12:46

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# ? May 10, 2024 06:28

SeaBass: Dec 30, 2003; NERRRRRRDS!

I'd put under arc flash reduction a site survey and arc flash analysis using computer aided tools. You don't have to get too in depth about it, but mention that in complex electrical systems it is the only way to get a somewhat accurate picture of the arc flash hazards.

# ? Jan 27, 2013 19:02

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