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Tapped into existing wiring, now my circuit/breaker isn't working

Tapped into existing wiring, now my circuit/breaker isn't working


  #1  
Old 09-16-14, 07:06 AM
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Question Tapped into existing wiring, now my circuit/breaker isn't working

I tapped into a circuit in my kitchen to install two new light fixtures. The only things previously on that circuit were three recessed light fixtures. I added two pendant lights which have yet to actually be installed (I have the wiring capped right now). I installed one of the lights and tested the wiring by turning on the breaker and no current ran through the line. The existing lights didn't come on and neither did my new fixture. I tested to see if the wiring was “hot” up-circuit to my new wiring and it was not. I attempted to replace the breaker (20A) thinking it might just be old but the new 20A tripped as well. I checked the capacity of the panel and calculated the load already on it and then upped the 20A breaker to 30A thinking I had added too much for the 20A to handle. When I replaced the breaker, I turned on the main breaker, then I turned on the new 30A. I heard a buzzing noise from the breaker and when I tested the lights I found that the circuit to the rest of the kitchen lights was no longer turning on. These lights are on a 15A on the breaker just below the one I replaced. That breaker did not appear to trip, but the lights won’t come on.

I replaced the 30A with the old 20A which resolved nothing. I stopped working on it for fear of doing more damage.

What have I done wrong and how do I fix it? I am not a stranger to electrical but this one has me lost.
 
  #2  
Old 09-16-14, 07:19 AM
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I tapped into a circuit in my kitchen to install two new light fixtures.
Explain in detail what you did.
 
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Old 09-16-14, 08:05 AM
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I cut into the existing line and bridged the gap I made with new wire. All 10 AWG gauge. I pigtailed off the junctions I made at the fixture boxes. The new wiring is currently capped with no fixtures attached. See the attached drawing of how the circuit is setup and what I added.

The old line is 10-3 and the new line is 10-3 (rated to 30A). The old line did not appear to be copper. The house is 30 years old.Electrical Wiring.pdf

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  #4  
Old 09-16-14, 08:43 AM
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The old line is 10-3 and the new line is 10-3 (rated to 30A). The old line did not appear to be copper. The house is 30 years old.
The only reason I can think of having 10-3 NM cable is that it is aluminum especially since you mentioned you think it is not copper. 10 AWG aluminum wire must be protected no higher than 20 amps. Assuming the house is 30 years old, it would have been built in 1986, about 7 or 8 years after aluminum wiring was last used in houses. Is it possible the house is older than you think? If you have aluminum wiring, you have many problems and a lot to do after you find this latest issue. Don't cover up your latest work till you have read and followed the instructions in the brochure I have attached a link to on how to repair aluminum wiring. Read this brochure and print it for future reference if you are dealing with aluminum wiring before you burn your house down.

http://www.cpsc.gov/PageFiles/118856/516.pdf
 
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Old 09-16-14, 08:56 AM
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The old line did not appear to be copper.
If it is aluminum it shouldn't be connected to copper with wire nuts though that isn't your problem. Your diagram looks correct. The problem is most likely in the connections. Just as a test try redoing the connections with the wire nuts. If it works you can replace the wire nuts with Alumicon connectors.
 
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Old 09-16-14, 08:59 AM
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I will determine whether it is aluminum or not. The house is definitely 30 years old so I am hoping I am looking at a coated copper wire rather than Al. If it is Al, I will be sure to bring out an electrician to remediate the issue.

In the case that it is not Al. What else might the problem be? Do I now need to replace the 15A breaker? I think I killed it but I will check it with a multimeter. Is it possible that my setup somehow shorted the system? Was upping to 30A a bad idea and should the 20A have tripped with the additions I made?
 
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Old 09-16-14, 09:10 AM
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Also, why would the breaker below the one I replaced stop delivering electricity to the circuit?
 
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Old 09-16-14, 09:25 AM
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It appears from your drawing you have put your black and white pigtails under one wire nut. That will short out the circuit and trip breakers.
Separate the pigtails and wire nut them individually in both boxes. After that try your circuit again and it should work.

RR
 
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Old 09-16-14, 09:43 AM
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Rough Rooster, you may be right on that. It didn't even occur to me that connecting the pigtails without a fixture attached might short the circuit. I'll be sure to give that a shot. I will be kicking myself if that is all the issue was.
 
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Old 09-16-14, 09:48 AM
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Good eye , Rooster. I kept looking at it and it didn't look right but I didn't catch that.
 
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Old 09-16-14, 10:55 AM
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I will determine whether it is aluminum or not.
Find a spot where the NM cable sheath is visible such as in an unfinished basement. Check the wording on the sheath and it may say "
Aluminum". Also, look at manufacturer's name; Alcoa and Kaiser names were both very common on Aluminum wire. If you cannot confirm it one way or the other this way, post a close up picture of the panel with the cover off so we can see the wiring connections at the breakers and the neutral bus. Hopefully you don't have aluminum wire, but I cannot think of a single reason why 10-3 cable would be used in a lighting circuit unless it was for 20 amp circuits with aluminum wire.
 
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Old 09-16-14, 11:27 AM
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I have a feeling that Rough Rooster gave the correct answer, but just to chime in;

Your drawing uses just one line to show power from the switch to the lights. There are a few different ways that the switch can be installed and it can have odd effects. (I apologize for using any incorrect terms here, but I'm not spending the time to look them up.) The switch could be on the hot line or the ground line, that could change how the new fixtures behave. They may not turn on, not turn off, or just be wonky.

Are you sure that's 10-3 wire? I only see two lines in your drawing (ground does not count; this is why Americans are bad at math :-) ).
 
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Old 09-16-14, 11:38 AM
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Are you sure that's 10-3 wire? I only see two lines in your drawing (ground does not count; this is why Americans are bad at math :-)
Actually it does make sense. Cable predates ground wires. Terminology was not changed when ground wires were added because for a few years cable was available both with and without ground wires. It would have been very confusing if a cable with 3 wires could be either black,red, white or black, white, bare.
 
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Old 09-16-14, 11:48 AM
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Terminology was not changed when ground wires were added because for a few years cable was available both with and without ground wires.
It makes sense if you understand the background. But let's be honest here; the cable has THREE wires in it. Calling it 10/2 confuses everyone the first time they encounter it. It probably should have been called 10/2g(round), but history has already been written.

Back to the topic.
 
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Old 09-16-14, 02:36 PM
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A house that is only 30 years old should only have switched hots. It is too new to have switched neutrals.
 
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Old 09-16-14, 06:38 PM
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But let's be honest here; the cable has THREE wires in it. Calling it 10/2 confuses everyone the first time they encounter it.
It isn't confusing if you look at the packaging or the sheath on the cable and see that 10-2 NM cable has 2 insulated conductors and 1 bare conductor.
 
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Old 09-17-14, 07:30 AM
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Ok, so the existing wire is coated copper rather than Al which is a relief. I disconnected the pigtails and switched the 30A breaker back to the original 20A. I reset the breakers but the lights still wont come on. I have confirmed that there is a current through the breaker now, but there isn't any current immediately up-circuit from the fixtures. The breaker no longer trips which means the pigtails were shorting the circuit (makes sense) but there is still no power. What the heck is going on??

Also, the adjacent breaker for the rest of the kitchen isn't working. I replaced it with a new breaker with equivalent amperage and there is still no current running through the breaker...
 
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Old 09-17-14, 05:35 PM
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So no fixtures are working? You didn't completely disconnect ALL pigtails, did you?
 
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Old 09-17-14, 05:39 PM
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I have confirmed that there is a current through the breaker now, but there isn't any current immediately up-circuit from the fixtures.
What does that mean. You didn't use a non contact tester did you?
 
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Old 09-17-14, 06:41 PM
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the existing wire is coated copper rather than Al which is a relief.
Coated? What color is the coating? Tinned copper wiring hasn't been used since the '50s, I have never heard of premises copper wiring being coated in over 50 years.
 
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Old 09-18-14, 05:52 AM
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Also, the adjacent breaker for the rest of the kitchen isn't working. I replaced it with a new breaker with equivalent amperage and there is still no current running through the breaker...
Hard to believe that this is coincidence. What is the other breaker connected to? Is it to the other wire of your 10-3?

Any chance the wires run to a GFCI that's been tripped?
 
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Old 09-18-14, 06:12 AM
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I replaced it with a new breaker with equivalent amperage and there is still no current running through the breaker...
How did you test the new breaker?
 
 

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