new home run


  #1  
Old 11-16-04, 10:50 PM
gonzo
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new home run

Normally I would feel like an idiot asking this question, but so far no one I have asked could actually give me an answer. I know it is wrong, but I don’t know what the potential problems are, even though it works fine right now.
I needed to add a circuit and the panel is on an outside wall of the house and I didn’t want to get into the wall, and I guess I was lazy too. Anyway I had rewired this house several years ago and had the home runs together in a group. I took two of them to a J box, cut one of them and put black heat shrink on the white wire, did the same at the other end (at the panel) and then used it as the power lead to the new circuit breaker, then I ran the new home run to the J box, used the wire that I put the heat shrink on for the hot lead, the original black for the original home run, and I used the white from the second home run that I took to the J box and tied it to the ones leaving. Basically I used the same white wire for three different circuits. I have had no problems with this so far, but what are the potential problems I could have.
Also, can you explain what a “floating neutral” is?
Thanks for the time. sincerely gonzo
 
  #2  
Old 11-17-04, 07:50 AM
J
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Sorry, but I read your post three times and I can't figure out what you're talking about.
 
  #3  
Old 11-17-04, 07:58 AM
sjr
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I am similarly confused. Could you post an image of what you are describing?
 
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Old 11-17-04, 08:29 AM
P
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If a single White wire conducts the Neutral current for 3 seperate 15 amp Branch-Circuits, the current in that conductor could be either 45 amps, or 30 amps, depending upon the connection of the 15 amp circuit-breakers to the two breaker Bus sections inside the panel

If all 3 C-B's connect to the same Bus-section, the Neutral-current in the White wire common to all 3 B-C's could be 45 amps. With 2 C-B's connected to the same Bus-section, the Neutral-current could be 30 amps.
 
  #5  
Old 11-17-04, 08:42 PM
gonzo
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new home run

thanks pat

Of course this brings up a whole bunch of other questions I feel stupid for even asking. I am usually the one who is being ASKED the question, and I always say, "there are no stupid questions, only stupid people who don't know and won't ask, no one is born with the knowledge, you aquire it" so...
let me see if i am clear on this. if the common (white wire) is used for two different circuits, then it is carrying or could accumilate as many amps as the breakers allow to go through them, if the breakers are hooked up to the same buss in the panel. Does this not happen if they are on a seperate buss. like running 220, black, red, and white, where two circuits (one off of each buss) share the common?
ques. if this situation can increase the neutral-current amps, can it also increase the neutral-current voltage? how would you check this? and wouldn't it burn up electric motors or blow light bulbs?

thanks again Pat
 
  #6  
Old 11-18-04, 07:26 AM
J
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If one neutral is serving two circuits on opposite legs of the power, then the neutral current is the difference of the two hot-wire currents, and thus can never exceed the current on either hot wire individually. So this is safe.

If you have three circuits sharing the same neutral, then there is no way that all three can be on different legs of residental power (since there are only two legs). Thus, this is always unsafe because the current might be twice what the wire can safely handle.

"Neutral-current voltage" is a meaningless term. What you are probably referring to is that the voltage through any individual load may increase or decrease if the neutral wire becomes disconnected and the other hot wire is forced to serve as the return. This can cause damage to your appliances and or burn out light bulbs.
 
 

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