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  #1  
Old 12-04-00, 12:19 AM
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I need to set my brother in-law straight. He claims that the white wire (neutral) doesn't have power to it. I don't know where I read or heard this: you can still get a shock by way of the neutral if a major appliance kicks in like the fridge or simply if someone turns a lamp on. I believe this is true if the power is on at the breaker but can this happen with the power shut off on that particular circuit you are working on. I'm going to print out the response and show him because I think he is too risky with electrical. He doesn't shut off power all the time. He's 25 - too young to get shocked.
 
  #2  
Old 12-04-00, 06:20 AM
J
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The neutral is the return path for hot juice. If there's no hot juice on a particular circuit there shouldn't be any return current, should there? Neutrals are permanently connected to the utility's neutral at your breaker panel, so operating a circuit breaker doesn't affect the neutral one bit. Only the hot ( black) is connected to a breaker.

Neutral should read ZERO volts to ground under NORMAL circumstances when a circuit breaker is open because there's no juice available, but it can read greater than zero when a circuit is live because it is returning current when electrical equipment is operating.

However, in many homes where people have done their own wiring they have interchanged the hots & neutrals thinking it doesn't matter. Before the days of polarized plugs you could unplug your toaster, flip the plug upside down and plug it in the other way, and you'd still get toast, leading many people to think hot & neutral are interchangeable. The previous owner of my home did this, and hot juice was backfed to some of my circuits when I lost one leg of my 220 once.

Also, both the hot and the neutral were black in the knob & tube days and many folks just couldn't tell which is which.

Here's where a voltage tester comes in handy.

As far as getting shocked when working on a de-energized circuit when an appliance on another circuit kicks on, the return current in that circuit ought to be heading straight back to the breaker panel via the shortest path, and not wandering all over the house looking for someone to shock. If the wiring is all properly done, that is.

Hope that's not too confusing. And if anyone else out there has an opposing opinion please jump in anytime.

JH
 
  #3  
Old 12-04-00, 07:54 AM
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Under "normal" conditions, a neutral wire will carry plenty of current but very little voltage relative to ground ... a few volts. Usually not enough to hurt you.

Under abnormal conditions, the neutral can kill you. This can occur if there is any breaks in the neutral between you and the panel where the neutral is grounded. In this case, the neutral wire can carry the full 120 volts. This can occur, e.g., when you have an outlet out of the box and the neutral wires are disconnected. These neutral wires can kill you if the power is on.

Finally, the big caution -- not all white wires are neutral. Some of them are hot, even in perfectly wired systems. These can definitely kill you at all times.

Whenever the circuit breakers are off, you should be safe -- assuming you've really shut off the correct breakers (not necessarily just one breaker).
 
  #4  
Old 12-04-00, 05:21 PM
Wgoodrich
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Guys you are saying neutral, not grounded leg. A white wire can be either a grounded leg providing the return path from the breaker of one circuit. A NEUTRAL CARRIES THE UNBALANCED LOAD OF TWO AND I MEAN TWO CIRCUITS. IF YOU ONLY TURN ON CIRCUIT OF THAT WHITE WIRE BECOMES A GROUNDED LEG STILL CARRYING CURRENT BACK TO THE PANEL FROM THE SECOND BREAKER IT SERVES.

Now if you have a grounded leg serving one circuit breaker 120 volts, then that white wire would not be carrying any current back to the panel and should be dead. If you are in a junction box and you break that white wire from the completed path to the panel, then the white wire coming from the load served by the single breaker would naturally be dead. However lets throw in a wild scenerio. Say you have a loose neutral in the meterbase. You have broken that white wire in the junction box of the single breakered circuit. Isn't the other end of that white wire still connected to the neutral bar that is starving for a path to ground because of the loose neutral? Isn't all the rest of the circuits in the house connected to the same neutral bar in the panel as that white wire you have broken in the junction box? Isn't all the load throughout the house trying to find an easy path to ground and is starving by the loose neutral in the meterbase. Wouldn't the current be glad to rush down backwards to the other end of the white wire you have broken in that junction box? If you are well grounded, say sitting on a grounded water pipe or standing in water, wouldn't your body be an easy path to ground for the return path load of the whole house that is starving for a grounding path due to the loose neutral in the meterbase?

This is why I commonly say a neutral is a wild card and can multiply like a coil well above the 20 amp rating of the wire if you get caught between that white wire and an easy path to ground, especially right through your heart?!!

Remember current kills, not voltage!!!!

Maybe this will help you to convince your relative to respect a white wire more than a hot. That hot is limited to 20 amps, the white wire is unlimited and is unfused, if current is fed backwards from the panels load. Remember that is take less than 10 thousandth of one amp to kill a human. This is why 5 milliamps is the maximum limit set for the design of a GFI.

Hope this helps

Wg
 
  #5  
Old 12-04-00, 07:21 PM
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Wg, thanks! I looked up what you said about the "neutral" wire. Of course as usual, you are absolutely correct. I have used the word "neutral" incorrectly a million times, but never again!

However, since I know you encourage a lively discussion, I must take exception to your statement, "if you have a grounded leg serving one circuit breaker 120 volts, then that white wire would not be carrying any current back to the panel and should be dead." I may have misunderstood, but if you meant to imply that the grounded wire of a 2-wire circuit doesn't carry current, I must disagree. In a 2-wire circuit, the grounded wire carries exactly as much current as the hot wire (although at substantially less voltage).

I also wonder about your statement, "if you are in a junction box and you break that white wire from the completed path to the panel, then the white wire coming from the load served by the single breaker would naturally be dead." This is subject to possible misinterpretation. Certainly, the white wire still connected to the panel is dead (except in the case of your interesting "loose neutral" example). But the other white wire -- the one connected to the outlets farther away from the panel -- may now have the full 120 volts on it (if the breaker is still on). This occurs if there is a switched-on lamp plugged into one of these downstream outlets. This white wire can kill you dead in an instant, even without a loose neutral in the meterbase (assuming the hot wires are all still connected).

I'm sure you already well knew everything I just said, but I thought a bit of clarification would help (just in case there is anybody still reading!!). Anyway, as always, thanks for the education.
 
  #6  
Old 12-04-00, 09:29 PM
Wgoodrich
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John Nelson as usual you caught me again. Assuming that is. I was answering the post that had the breaker in the off position. After rereading my reply I came to the conclusion proof reading is a valuable tool!

John Nelson said
" I may have misunderstood, but if you meant to imply that the grounded wire of a 2-wire circuit doesn't carry current, I must disagree. In a 2-wire circuit, the grounded wire carries exactly as much current as the hot wire (although at substantially less voltage).

My opinion
It is true what you said. Yes you misunderstood my thoughts, but not the way I wrote my thoughts. I opologize for my failure to be clear in what I wrote. The words that I wrote was continuing the post which had the breaker in the off position. A grounded leg does indeed carry the same load as the hot as a return path.

John Nelson said
I also wonder about your statement, "if you are in a junction box and you break that white wire from the completed path to the panel, then the white wire coming from the load served by the single breaker would naturally be dead." This is subject to possible misinterpretation. Certainly, the white wire still connected to the panel is dead (except in the case of your interesting "loose neutral" example). But the other white wire -- the one connected to the outlets farther away from the panel -- may now have the full 120 volts on it (if the breaker is still on). This occurs if there is a switched-on lamp plugged into one of these downstream outlets. This white wire can kill you dead in an instant, even without a loose neutral in the meterbase (assuming the hot wires are all still connected).

My opinion
Again what I thought was not clear in what I wrote. My intent was to say the the grounded current of the whole house would backtrack down that white wire to where you made the break in the junction box. I was trying to show if this break had a better path to ground that the loose neutral in the meterbase due to the resistance of the loose connection then the wire coming from the panel could sneak up on you and hit you with the full current of the entire house due to the easier grounding path your body may have made.
As for the white wire coming from the load of the single breaker, I said it would be dead again thinking of the breaker being in the off position.
My problem at times is that I think faster than I type and then fail to proof read for misunderstanding of intent.
I was actually magnifying your statements in your previous reply in an imaginary situation trying to show the dangers of a grounded leg or a neutral.
My intent also was trying to show that having a single breaker off does not make that white wire dead if that white wire is a neutral. Trying to show a false sense of security in the person that has a lack of respect for a grounded leg or a neutral. In my opinion a grounded leg or a neutral is the most dangerous wire because of the lack of respect and the voliotility of a grounded leg or a neutral seeking a path to ground.

John Nelson thanks for watching my back. I especially needed it this time.

Wg
 
  #7  
Old 12-05-00, 10:06 AM
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OK, maybe you have to crack me across the forehead with a 2 x 4 to get my attention. I read the first paragraph of WG's first reply three times before I finally thought I understood. Are we saying that the term "neutral" only applies to circuits with more than one hot leg? I have used the terms "neutral" and "grounded conductor" interchangeably since I was in diapers practically, and never thought twice about it. So when John replied that he'd never make this mistake again I pulled out article 100 and, as usual, the definitions I'm looking for aren't there. Can you just clarify for me once and for all that what you're saying is that the white wire of a single-pole circuit is never called a neutral?

I don't want to open a whole new can of worms here, but where does this leave the term "common"?

Thanks guys.

JH
 
  #8  
Old 12-05-00, 11:03 AM
Wgoodrich
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Juicehead,

A neutral must serve two hot conductors.
A grounded leg can only serve one hot conductor.
A common is an entity in contact with other entities relating that entity as a whole as one entity. A common can be found in either a hot or a grounded conductor. An example of a hot common would be the brass two brass [hot]screws of a receptacle, or a black or brass screw of a three way switch.
The term common can not identify whether it be hot or ground.


I decided to post details of these terms form a pass out I wrote in the past when State officials in my State asked for an explaination of this same subject.

You might want to look for a post titled grounded leg vs neutral.

Wg
 
  #9  
Old 12-06-00, 04:58 PM
sprky
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Exclamation

hello sowewo,
mabe this will convince your brother in law that the grounded or nutural conductor can bite you some times worse then the hot. today me and another electrician had to go and finish up some work in an office building with 277V lighting, that was started by another electrician. the guy i was working with was working above the celling on a 10' step ladder, and needed some material from the truck, i went to get it and whin i came back he was hung up on the nutural conductor, i had to knock the ladder out from under him to free him. the grounded conductor or nutural can zap u especiely whin there is a load down stream, what hapens is whin u grab the nutural or grounded conductor and there is a load you compleat the circuit of the nutural, and get a good jolt this can hapen no mater what the voltage is. needless to say the job didnt get finished as i spent the remainder of the afternoon in the er. my co worker was lucky that it didnt kill him, as it verry well could have.
ALLWAYS AND I DO MEAN ALLWAYS WORK A CIRCUIT DEAD, or you may end up dead.
 
  #10  
Old 12-06-00, 06:58 PM
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Gentlemen,
This very conversation is why I have mentioned several times we need to be sure that the person that is asking a question is using words in the same manner that we are answering,NEUTRALS are with 2 HOT WIRES . A GROUNDED CONDUCTOR [ also WHITE ] IS FOR 1 HOT WIRE A multi wire circuit has a neutral [ white ] and those are ran in a lot of places if you unhook that neutral wire then the power from the other leg is still traveling back up the neutral.A LOT OF TIMES A MULTI WIRE CIRCUIT IS TERMED A GROUNDED CONDUCTOR AND PEOPLE DO NOT REALIZE THAT THE WHITE WIRE CAN STILL BE CARRYING CURRENT EXCUSE THE CAPS will take 10 lashes with some #18 thhn . With a multi wire you have 2 hots coming from 2 different breakers and one white wire if only one breaker is turned off then ouch or worse the wire blows up at 64,000 feet a second and you are permently blinded.The person that ask this question may really be talking about a neutral or he could be talking a bout a grounded conductor
 
  #11  
Old 12-06-00, 08:37 PM
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Well guys, thank you for all your responses. I'll be showing them to my not so cautious, no it all in-law. It amazes me how some people don't respect the power of mother nature. I myself always shut off power.
 
  #12  
Old 12-07-00, 04:33 AM
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WG, thanks, I found and printed the post you referred to.

JH
 
  #13  
Old 06-19-02, 07:53 PM
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we need to be sure that the person that is asking a question is using words in the same manner that we are answering,NEUTRALS are with 2 HOT WIRES . A GROUNDED CONDUCTOR [ also WHITE ] IS FOR 1 HOT WIRE

Like the other guy said, I for many years, referred to the white wire in say, 12/3 with a grond as a ground wire. Several years ago , it was pointed out to me that the white is not atually referreed to as the ground wire but a neutral, or was that a common? Anyway, I normally refer to the white wire in 12/3 grd as a neutral when not actually used as a hot wire. Example: switch leg.

I agree with what Doc said in the above quote. We really do need to know we are on the same page when on this subject. I usually try to read the past posts to get a feeling of what is what in some cases. Not to mention, that I also reread and read some things to try and decipher what is being said and to make sure I am on the same page.
 
  #14  
Old 06-19-02, 09:50 PM
terrywouldbe
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With a multi wire you have 2 hots coming from 2 different breakers and one white wire if only one breaker is turned off
ouch or worse the wire blows up at 64,000 feet a second and you are permently blinded

Please explain this further.

I haven't learned of this safety issue. I know that Breakers come as Double Pole, meaning (I think) one wide breaker with two switches tied together, and a common trip.

These would be used for a 3 wire system, correct?

So, it would be dangerous, you say, to turn off one of the switches at a time?

The DP Breakers that I have seen come with the switches tied together with only a plastic sleeve, which can easily come off.

Can you explain this occurence a bit more? Why would the wire "blow up" and hurt (blind) someone.

Thanks,
Terry
 
  #15  
Old 06-19-02, 09:57 PM
J
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Please note that this thread is more than 18 months old. boman really dragged the bottom of the lake to come up with it. I'd be surprised if a guest named "doc" is around any more to explain further.
 
  #16  
Old 06-19-02, 10:34 PM
terrywouldbe
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Doc's out

hmm; could anyone else expand on Doc's comment?

Thanks for pointing out to me that I need to look at the dates :-)

-Terry
 
  #17  
Old 06-19-02, 11:30 PM
Wgoodrich
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Terry I will give it a shot what doc was trying to say. In my mind he was running two actions at once in that statement.

IF you have a unbalanced 220 volt circuit that say has 10 amps on line 1 and 20 amps on line 2. The neutral would be carrying the unbalanced load being the difference between the two hot conductor loads totalling 10 amps.

If you just shut off one of the two sides of a 220 volt breaker being the larger load say, that neutral would instantly jump to be carrying 20 amps instead of 10 amps because the second hot was countering the original 10 amps. When you shut off half that breaker then you would have a major rush of electricity onto that neutral wire that just became a grounded leg instead of a neutral conductor.

I believe that doc then mentioned an open neutral. When a neutal is loaded and not connected to a path back to the transformer that neutral is looking for a path to ground. If your body becomes that path to ground that loaded neutral will shove a rush of current through your body until that neutral has unloaded. This rush of an open neutral blasting through your body is much like an over blown balloon popped by a needle. Bang the current rushes through your body to ground type activity. Most people don't have respect for a neutral wire because they think it can not be that dangerous being connected to the same bar in the panel as the bare equipment grounding bar. Problem is an open neutral is not connected to that bar. It is an orphan out there in the structure trying to get back to that neutral bar. This is why the often say the neutral wire is more dangerous than a hot wire because of the lack of respect of the dangers that open neutral possess.

Hope this helps

Wg
 
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Old 06-20-02, 04:53 AM
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Please note that this thread is more than 18 months old. boman really dragged the bottom of the lake to come up with it.

I have been known to look at past posts to get oriented to a forum and sometimes to look for an answer to a guestion I might have that has already been answered. I found this old post and knew it was an old one, but it caught my interest. I thought I would inquire further. It does seem to mention an important point ( I feel). No intention to irritate anyone.
 
  #19  
Old 06-20-02, 03:19 PM
masterjoe
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Talking 2nd best method??

I actually spent 30 min reading all posts and it was definitely worth it. It has opened my eyes and I'm now more cautious about that 'white wire' than ever before. Thanks, guys!!

I know that shutting down the main breaker to the house is the best method to prevent any mishap; but, what's the 2nd best thing to make sure that a particular circuit that I'm working on is completely de-energized after I shut off that individual breaker??
What I meant is that possible 2nd breaker circuit involved. I've been using a generic method to hook up a lamp and find a breaker that turns lamp off.
I have a digital multimeter; after lamp turns off, should I still check for V & I before I disconnect and touch the wires??
If so, what kind of measurements am I looking for??
 
  #20  
Old 06-20-02, 08:24 PM
J
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Test every single wire before you touch it. A simple neon test light may be the best tool here, since phantom voltages often fool digital multimeters.
 
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Old 06-20-02, 08:34 PM
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It has opened my eyes and I'm now more cautious about that 'white wire' than ever before.

Joe, if I prompted you to look at this post which you may have missed because it is so old, this is just another case that makes me feel justified when I ask what seems to be an inane guestion of the experts; especially when it is something that can prevent injury or death. I have been told that the only dumb guestion is the guestion not asked. I have to agree to some extent. We can all ( well, alot of us ) learn from the guestions of others and the answers from the ones who know and care to give them.

I do appreciate the info from this site, and I wish I could help people in the same manner, as I have a few times in the Electrical Appliance forum, either with answers to problems or with guestions that were answered by someone with the knowledge.
 
  #22  
Old 06-21-02, 10:46 AM
Tom Carter
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Even though the first part of the thread is 18 months old, it's still extremely enlightening discussion. As always, the main disagreements seem to stem from confusion or misuse of terminology. Anyway, for us lightweights, it's kinda like srumbling into a jungle clearing and watching elephants fight! Thanks, guys.
Tom Carter
 
  #23  
Old 06-21-02, 04:24 PM
Wgoodrich
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Tom, elephants like electricians don't fight, they discuss and discuss and discuss louder and then afte 18 months they rediscuss again.

Funny how after so long of a time has passed and we are still discussing just involving different subjects as time goes by.

In those discussions not only the beginner learns but those elephants you speak of learn too, almost daily from each other and often times from those beginners that think they can't be of help ! Sometimes those elephants are so deep into a subject the can't see the simple things like forgetting to turn on a switch or plug in a cord when something isn't working. We never seem to stop learning in this forum ! Thanks to all who speak up. Don't be afraid to speak what you are thinking and make a mistake. We elephants are quite skilled at making mistakes too, how else can we learn so much about such a deep subject?

Wg
 
 

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