te12co2w

200amp? I can't imagine all that in a 2" anything.

te12co2w

I admit it, I still do it with the lower voltages. Just yesterday in fact.

randas

Never done it but I'd say stagger the splices

mattsilkwood

I've done it in the past, continue to now and probably will in the future. It's just a fact of life doing what we do. Do you guys honestly kill power every time you add a circuit, change a ballast, pipe out of a panel or things such as this?

And if you do, do you still have these customers?

Most of the time power can be shut off with out many problems but for the times when its not feasable thats what makes us electricians, having the knowledge and training to do it safely.

NewBack

You're right, 120v could kill you just as dead as 600v... ...the same exact way that a stick of dynamite could kill you as dead as a 20 megaton nuke.

But if you want to speak more realistically, high voltage has a greater propensity to kill a person or do bodily harm, such as internal burning to the point of amputation, external third degree burns, splashed molten metal, etc. etc. etc.

Zog

Actually it is the opposite, higher voltages cause a "skin effect", so the current tracks on the surface of the skin and will not penatrate the skin and cause burning of the nervous systems and blood vessels. (Same reason hollow tubes are used for HV outdoor substations, no need for the center to exist)

Lower voltages puncture the skin and cause current to flow thorugh the circulatory and nervous systems causing internal burns and nerve damages.

Of course voltage is only 1 of 8 factors that determine the severity of an elcetric shock, but discounting all other factors, lower voltages are more dangerous than higher voltages simply due to the skin effect.

NewBack

Can you show me a man with blown out knees (as in GONE, no lower legs) from 120volts? How many amputations does 120volts cause?

captkirk

Seriously......Skin effect....? now thats a bit of a stretch to keep me from doing my own service changes.

headrec

Personally I have worked live more then a handful of times and I'm only a 2nd year apprentice. I kind of enjoy the thrill. You definitely have to be careful and if you aren't comfortable don't do it plain and simple.

__________________
-Jay

Zog

I never said anything about 120V, and if you read my post I was talking about voltages only. A "blow out" type injury results from the current entry and exist points. The current will depend on the difference in potential across the body and the resistance of the path, so obviously there is usually more current on higher voltage systems.

LV internal burns are minor at first glance, but the internal damage done to the blood vessels causes a lack of oxygen to the cells and the tissue will begin to die after a few days and progress into a case where aputation is required to save the life of the victim.

Zog

Not a strech, just basic electrical thoery. Skin effect starts to become evisent around 24kV.

NewBack

I was comparing 120V to 600V and you quoted me and replied:

So don't tell me that I am wrong if you are talking about a completely different issue.

rewire

Talking reality more people are killed or injured by lower voltages because of the tendancy to take for granted the danger present.Look at those who casually talk about working live circuits.

Faultfinder1

Here we go with this same old stupid argument again, and my answer is the same - if you don't think that 120v will kill you then go ahead and get your affairs in order, write out your will, and keep on working it live/unprotected. NO - I am not going to waste my time explaining this to anyone that refuses to believe, nor will I research the hundreds of deaths each year of electricians that used to have that same attitude, you can (and should) do that on your own.
It is an industry-wide, well known fact that Linemen fear 277/480 much more than they do 17k, 33k, or higher AC Voltages. Electricity is a nasty bi*ch and if we don't respect it too many of us will pay the price. Be safe, be well, and go home everyday.


www.faultlocating.com

Zog

No, you said

120 and 600 are both low votage, your statement is incorrect regarding high voltage and internal burning is incorrect and I was correcting it with the actual paths different voltages take through a human body.

I spent 15 years researching and training on the effects of different variables in electric shocks, I have been called on as an expert witness in many cases and have been a technical advisor on 2 novels with forensics of electrical shocks as the storylines. In my experience very few people that work live have any understanding of what determines the severity of a shock injury. In fact, many experts dont underatand everything, DEI (Diffuse Electrical Injuries) is still something that is being researched.

NewBack

You're right, more people are killed by 120V than higher voltages, but that doesn't make 120V more dangerous than the others.

More people are killed by knives than nuclear bombs, what point are we trying to prove here?

NewBack

I disagree. I consider 600V to be high voltage as far as this discussion. On the job, we consider 277V to be high voltage. On the pole, things are different. The terms "high and low" voltage need to be qualified in the discussion. I believed it was pretty clear what I was talking about, you just wanted to argue. You KNOW that I was comparing 120V to 600V, you conveniently left it out when you were quoting me.

No, my statement was NOT incorrect. 600V has a greater propensity for injury or death than 120V. You can argue all day, you will still be wrong.
Honestly, I do not care. Keep your resume to yourself, it doesn't impress me.

All you have done is pulled semantics games and twisted words around.

I stand by my original statement the 600V is more dangerous than 120V. Prove that fact wrong instead of dancing around it, if you can.

rewire

I never stated that 120V was more dangerous but that it had the same potential to kill,dead is dead it wont matter how you got their.

Peter D

I suppose to define our terms as to what "dangerous" really means. I forget the exact number, but I think anything over 50 volts has the potential to kill you. So really almost all voltage that electricians deal with on a regular basis is deadly. When I think of "danger" in this discussion, I consider the level of willingness by electricians to work on it live without any safety precautions.

120 volts is more dangerous because people take such a cavalier attitude about working on it live. Although there are plenty who will dive into a live 480 panel without a care in the world, so one is not any better than the other except that if something goes wrong in that 480 volt panel, you will likely be severely burned in the process.

The high voltages (outside distribution) are not dangerous in the sense that regular electricians almost never work on them, and those who do (linemen) are equipped with safety gear and years of training. They know how to safely handle those voltages and are well equipped to do so.

Zog

The title of this attached chart (From OSHA) is "Frequencies of Electrocution Incidents Identified by FACE by Low Voltage Level (<600 Volts), 1982-1994"

Note the definition of low voltage as <600V, which is the same as the IEEE defined voltage classes. What "you think" voltage classes are defined as matters little to me, you think wrong.

You asked to be proved wrong, there you go.

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