Dangers Of Stray Current, as in power that can shock you...

Yes it's true, you can get shocked by stray current and it can also disrupt your electrical devices... Something I thought everyone should be aware of seeing as some people are experiencing what seem to be electrical phenomena which this could be the cause of...

Dangers of Stray Current Full Source

The uncontrolled flow of continuous electric
current over the earth, building steel, metallic piping, etc. has
become a serious problem that lacks recognition by the
greater part of the electrical industry. The resulting electric
shocks appear to be of little concern to the majority of the
electric utilities, electrical engineers or the public. However,
with the advent of sensitive computers and electronic
equipment, the problem will continue to grow. The recognition
of electrical hazards associated with trailers, marinas and now
ranges and dryers being wired with only three wires, has
brought changes to the National Electrical Code. No longer
can a single conductor serve as a neutral and ground. Due to
electric shocks to humans in swimming pools and showers,
this logic needs to be extended to the services to residences,
commercial establishments and industries to protect
occupants from potentially hazardous electrical shocks.
Index Terms – Electric shocks, Continuous current, ground
current, Neutral Blocker, Uncontrolled current flow.

Uncontrolled Flow of Continuous Electrical Current – In
this paper the uncontrolled flow of continuous electric current
is the flow of continuous electric current over the earth,
building steel, metallic piping, etc. from the multiple
connections of the neutral conductor to earth or ground or
from the interconnection of neutrals from different electrical
systems, which have multiple connections to earth or ground.

The uncontrolled flow of continuous electric current over
the earth has become a serious problem that lacks recognition
by the greater part of the electrical industry. What has started
out as a problem for farmers and their cows failure to drop
their milk, due to electrical shocks, has now spread to humans
who are receiving electric shocks in swimming pools and
showers.
The flow of uncontrolled current over the earth appears to
be of little concern to the majority of the utilities, electrical
engineers or the public defenders. However, with
the advent of computers and other sensitive electronic
equipment, operating on lower and lower voltages, they are
becoming sensitive to noise and stray current generated
voltages.

Actually, this is a well known phenomenon, especially among electricians.

The ground line in your electrical sockets was created because of this phenomenon.

There was a point in time when household AC used a single line to shunt through. No neutral, no ground.

What happened was the atmosphere itself would build up a static charge in the frames of buildings and in the electrical wiring itself.
Over time, this charge would get so powerful that electricity would literally arc clean across electrical outlets, into peoples hands, etc... attempting to get back to ground.

This is why they added the second prong. The ground prong. (Thats the wider flat connector of you're in North America.).
Now. Another issue arose out of this.

If your appliance was grounded through the case, or became wet, and you touched it... you would quickly find out that your body conducts electricity a little better than a grounding rod in your basement might.

So, people were becoming part of the circuit (if the earth is one half of the circuit, and you're standing on it... you are in effect one half of the circuit.)
People were getting killed... pretty frequently actually.

So some genius came along and decided, hey, if we create a third line, and lead it back to say, a circuit breaker, we can trip the breaker before anyone gets seriously injured!
They called this line neutral.
It's the unhappy mouth looking prong on the outlet.



I have a link to the history of these plugs... one sec...
Why three prongs on an AC outlet?
Here you are.

That explains it better than I can.


It seems what is happening in this case of it, is that we have passed so much current through ground (the earth) that it is literally looking for ANOTHER grounding source.
Basically, we become the ground, because we have less of a charge than the ground does.

Basically its the same problem, just on another part of the circuit.... the most important part. The one we can't replace. lol

I think that is why we use in Portugal a thing called differential circuit-breaker, that cuts the power when it detects a difference between the entering and the exiting currents, meaning that somewhere there is a "leak" in the current.

reply to post by johnsky


That site was great, thanks.

Most countries now adopt the M.E.N. system (Multiple Earthed Neutral) as standard. Remember that unless you manage to insert yourself in the circuit, it's not really the normal circuit current that's poses a danger to you - it's the voltage developed by the circuit current across whatever impedance it encounters under fault conditions that will determine the level of 'shock' you experience. Remembering a little electrical theory: the more parallel paths you have, the lower the overall impedance will be and applying some principles of Ohm's law shows that the voltage drop across a circuit is proportional to the product of current and impedance.

The M.E.N. system has the neutral earthed at the starpoint of the distribution transformer and at every customer's swichboard creating multiple parallel paths between ground and neutral to guarantee low impedance and low voltages appearing on the earth during a fault. Even though the earth is actually a neutral it should only carry current when there's a fault and that's the principle of earth leakage circuit breaker (ELCB) protection.

Modern RCDs (Residual Current Devices) or previously called Core Balance Relays compare the current in the active and neutral of a circuit for perfect balance and amplify any errors to trip the circuit breaker for differences of 30mA or less which indicates that some of the circuit current is being carried by the earthing system EG by a person contacting a live conductor and an earth simultaneously.

Maybe power like many other things us humans jump into is something we don't completely control yet? I've seen a couple posts here on how others feel like they can't move, or how they hear a buzz and can't move their leg etc. Also how they experience problems with electrical devices and lights turning on etc.. I think this sort of thing if in the right place with the correct conditions might contribute to the phenomena these people are talking about... I don't think it's an abduction thing like most are concerned about... However, maybe the same type of feeling is also experienced during an abduction phenomena because aliens use an electric field to abduct you?

I'd say if you live in a house or apartment that isn't grounded correctly or if tested shows you have stray current all around you and if you're by a rail system like a subway or other electrical rail system there is a good chance you are dealing with stray current and don't even know it.. I could be wrong here, but the source I provided shows it can interfere with electrical devices.. Also there are cases of stray current that have killed live stock and even some guys dog... Of course that being worse case scenario...

Also don't muscles cease when you get shocked? If in fact you are being shocked by stray current at that degree wouldn't it disable the ability to move some or all of your body? I guess the question would need to be answered by someone who has been shocked... Also might be interesting to know if when they got shocked if they heard buzzing...

I've been electrocuted many times

Usually it just hurts like a ***** and feels like it is pushing me away from whatever is shocking me.

The worst one I experienced was from an ignition system (a couple thousand volts) in a van I was working on. The distributor was located right next to the drivers seat and I forgot to put the cap back on before I started it. With no cap for the current to flow through I became the closest conductor to ground. It nailed me at least 8-10 times before I fell out of the seat. It immobilized my whole arm for a little bit and hurt like hell. After a few minutes it went numb and left me with a real strange tingly sensation throughout my body for the rest of the day. Very uncomfortable...no buzzing in my ears though, although I've read that people who receive extreme shocks (ie lightning) will have their ears ringing for awhile.

And as someone who has experienced the sleep paralysis your talking about, I can tell you that being electrocuted is wayyyyy different.

reply to post by PlausibleDeniability


When you get electrocuted, the muscles in your body are tricked into pulling.
Depending on which muscles get the brunt of the shock will determine whether your hand for instance, closes around the contact, or pushes open.

If you get pushed from a shock, you're pretty lucky, it means your hand didn't get a chance to grab before your arm convulsed and thrusted you away from the source of electrocution.

I've been hit a few times myself. I say hit, because it really does feel like something has battered you repeatedly.
I'm pretty lucky that I'm not dead.

Be careful though. Electrocutions are accumulative. Meaning the damage builds up over time. The last shock of your life can be one that normally wouldn't do much to anyone. Assuming you've had enough shocks prior to that.

reply to post by johnsky


So you're saying if you get shocked several times it just keeps building? So then something small like static shock could then kill you?

reply to post by ElectricUncleSam


It's a matter of how severe the shocks were and what part of your body it passes through. Your motor nerves that control muscles are very delicate fibres and they function electrically so, like any electrical circuit, an overload can damage/destroy them and I've known people to lose the use of arm due to extreme electric shocks because the connection between the brain and the muscles has been 'burnt out'.

Shocks passing current through the chest are very dangerous because the nerves controlling the the most vital functional muscles like heart and breathing can suffer - the common type of shock you get when touching a live terminal with one hand while the other is touching a solid ground (eg touching a faulty unearthed electrical appliance while your other hand is touching the sink or a metal tap). Every such shock can build up the damage over a lifetime until a relatively minor one finally is the last straw and the heart goes into fibrilation with tragic consequences.

Typical static discharge shocks are very short impulses and nowhere near as damaging as contact with mains voltages in the 50-500V range. Lower voltages tend to just shake you up with a chance of getting free of it and higher voltages (1000+ V) cause such violent muscular contractions you tend to be thrown away involuntarily with burns from the arcing. The amount of current that gets below your skin and affects nerves is determined by the voltage and your skin resistance at the time. If you're wet, a much lower voltage can kill you than when your skin is dry. A good example - put your fingers on the terminals of a 9V battery and you'll feel nothing, with wet fingers still no sensation for most people but what happens when you put it on your saliva covered tongue?



[edit on 30/3/2008 by Pilgrum]

On the actual topic of stray currents, a heavily loaded AC conductor can induce voltages and eddy currents in nearby metallic objects and that's where adequate earthing is required to shortcircuit such electromagnetically induced voltages.

I've spent a lot of time working in EHV switchyards with very highly loaded conductors all over the place and induction in those situations is a huge consideration for safety of workers on parts of busbars, switchgear and transmission lines taken out of service for maintenance. There's been fatalities caused by these induced voltages when insufficient earthing is applied as an example of how lethal it can be.

This induction is a function of ampere.turns which determines the magnetomotive forces developed and the force decreases according to the permeability of the medium (air in most cases) and the inverse square law. Two adjacent pieces of metal could be considered as a 1:1 transformer and the induced voltage on the un-energised piece of metal becomes dependant on the current in the energised conductor. An example is two transmission lines strung on opposite sides of steel towers for tens of miles and one side is out of service while the other is carrying say 1000A. A voltage of 100s of volts above ground potential (deadly) will be present on the presumed dead conductor under those conditions. In fact any piece of metal up to 10s of metres from that live conductor will have an induced voltage on it unless it's solidly earthed which short circuits the induced voltages.
.



[edit on 31/3/2008 by Pilgrum]

reply to post by Pilgrum


Ok you sound smart... What are you talking about?

click on the link in my signature to learn more about my avatar

I know a thing or two about eddy currents

*twitch*

Sri Oracle

reply to post by Sri Oracle


Mind sharing what you know? Or are you advertising something?

Originally posted by ElectricUncleSam
reply to post by Sri Oracle

 

Mind sharing what you know? Or are you advertising something?

in my signature, click on:

...but Sri, why the evil avatar?

I live under high tension lines and I rent homes to people under high tension lines. You can read about my experience in that link.

I'm definately not "advertising" anything with my thread. If anything... I'm hurting my ability to keep occupancy. I do my advertising in the Thrifty Nickle.

Sri Oracle

[edit on 12-4-2008 by Sri Oracle]

reply to post by PlausibleDeniability


One can only be electrocuted once, as the term means to be killed by electricity

I know the term is often used to describe someone who is shocked, but the suffix "-cuted" means to be killed by.

reply to post by johnsky


It depends also on whether you are shocked by AC or DC. AC will push you away, due to the switching of polarity, thereby making muscles contract and expand with the current.

DC, on the other hand, such as found in third rails for trains, will not have this affect.

Quite often, numpties who play on the railway and touch the third rail will find themselves stuck to it and will cook in their own body fat as the current flows.

My mistake, so then I've been shocked many times. Whether your electrocuted or shocked I'm sure it still hurts the same

Its been a few years since my last vocabulary lesson and my mental dictionary is missing a few pages, so thanks for filling in one of the many blank pages

Originally posted by stumason
It depends also on whether you are shocked by AC or DC. AC will push you away, due to the switching of polarity, thereby making muscles contract and expand with the current.

Well not exactly

AC at 50 Hz in the UK (60Hz in US) actually hits peak voltage (and therefore peak current) at double the frequency (100 peaks/sec) but it passes through zero just as often so muscles try to contract and relax at that rate which is the reason AC shakes you but muscles don't reverse direction with polarity. DC just grabs and fries you with no shaking but either way is nasty.

If you're going to touch something live at mains voltage try and do it with the back of your hand or fingers - the contraction will pull you away from the source.

You know whats great is people that think you can be shocked by a car battery. I used to work at an auto store and would freak people out by grabbing both terminals and act like I'm convulsing. But in reality the voltage is too low on a car battery to do anything. However they produce hundreds of amps of current which if you were to lay a wrench across the terminals will weld it to the terminals and make the battery explode. A car's ignition system is around 50,000 volts but very very minute amperage.

Originally posted by bigshow
You know whats great is people that think you can be shocked by a car battery. I used to work at an auto store and would freak people out by grabbing both terminals and act like I'm convulsing. But in reality the voltage is too low on a car battery to do anything. However they produce hundreds of amps of current which if you were to lay a wrench across the terminals will weld it to the terminals and make the battery explode. A car's ignition system is around 50,000 volts but very very minute amperage.

I've known people who could feel the effects of current through them from contact with voltages as low as 12V because the deciding factor is the resistance in combination with voltage. 30mA is the 'safe' threshold at which residual current devices protecting household circuits will trip to prevent injury. 12V can induce currents in excess of that if the resistance is low enough like