two arc fault circuits out of a 14-3 romex?


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Old 10-29-08, 09:36 AM
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two arc fault circuits out of a 14-3 romex?

I am building a new house...also playing electrician.

I tried to save a run of wire by using a 14-3 to get power to two of my bedrooms. I used one of each "hot" to create a different circuit for each bedroom.

This was not a problem before I learned I needed to run arc-fault circuits to the bedrooms. These circuits trip as soon as they are engaged. The way I accomplished running these circuits... is to split the neutral wire in the main panel... and run one split to each AFC.

Is there a fundamental problem with this wiring... or more likely some sort of actual arc fault in one of my wired plugs?

Any advice is much appreciated!
 
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Old 10-29-08, 10:00 AM
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To my knowledge, there is no product that will support what you need. I know of no double-pole AFCI breaker on the market. You'll need to rerun the 14/3 with two runs of 14/2, or use 14/2/2.

Using 14/3 to reduce voltage drop is sometimes worth it for very long runs. Using it to save wire is almost never worth it.
 
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Old 10-29-08, 10:31 AM
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Is there a fundamental problem with this wiring
Yep. AFCI circuits cannot share a neutral wire unless you have a two-pole AFCI breaker.

The good news is that there are a few two-pole AFCI breakers on the market; Eaton makes them to fit both CH and BR panel, and Siemens makes one to fit Q-series panels, I don't know about General Electric or SquareD/Homeline. The bad news is that it's going to cost a lot more than you saved in wire and you will have to special order the breaker from an electrical supply house.

Part numbers:
cutler-hammer 3/4" CH panel: CH215AFIT or CH215AF
cutler/bryant/westinghouse 1" BR panel: BR215AFIT or BR215AF
siemens 1" q-series panels: Q215AF

Or you could wirenut the red and black wires together at the panel and pigtail them to a single 15A AFCI breaker. This puts your two bedrooms on the same circuit, but it would never be a problem if you don't exceed 15A.

Or you could install another run of 14/2 to the split point and separate the circuits.
 
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Old 10-29-08, 11:37 AM
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Originally Posted by ibpooks View Post
Or you could wirenut the red and black wires together at the panel and pigtail them to a single 15A AFCI breaker. This puts your two bedrooms on the same circuit, but it would never be a problem if you don't exceed 15A.
Excellent advice... that worked perfectly.

If I could, I have one more AFC question.

I still have one AFC that trips as soon as it engages. Is that most likely some sort of incidental contact somewhere in my outlets?

I have about 8 outlets daisy chained together for this circuit. I assume that if I just disconnect one at a time I will have a good shot at trouble shooting my issue?

Thoughts?

Dave
 
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Old 10-29-08, 11:48 AM
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Yes that's commonly a bare ground that's touching a screw when the wires were folded back into the box.

The first test is to disconnect both white and black wires from the breaker terminals and make sure it will reset with nothing attached. It's fairly common to have AFCIs bad right out of the box.

Next, it's actually quicker to disconnect the middle receptacle so then you know if the problem is in the first half or second half of the circuit, then disconnect the middle receptacle of that half to check whether the problem is in the first half or second half of that half thus saving you time checking good receptacles.
 
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Old 10-29-08, 01:56 PM
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OK.... I'm getting closer... but still having problems.

I have discovered that the outlet 2nd to the end is my issue. What I really mean to say is....

When I have nothing plugged into the outlet... I have no problem. As soon as I plug my TV into that outlet (even if the TV is off)... the breaker trips.

Any ideas?

Dave
 
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Old 10-29-08, 02:15 PM
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It's probably a pinched wire or something like that in the box which is connecting or breaking connection when you use the receptacle. Also check for silly mistakes like polarity reverse (hot and neutral on the wrong screws) or short (hot and neutral screwed to the same side of the receptacle). Did you try it with the receptacle pulled out of the box so you can see that no wires are touching?
 
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Old 10-29-08, 02:28 PM
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Right now I have the outlet pulled away from the box...when nothing is plugged in... I am fine.

As soon as I plug the TV into the outlet ... the breaker trips.

I have replaced the outlet itself... same issue.

I'm pulling my hair out!!!!!

One other question. Is it possible that my problem is occurring in another box... and the draw from the TV simply trips the breaker?

Update: I have plugged the TV into the last outlet (past the one I have been referencing)... it tripps the breaker when plugged into that outlet too. I guess it isn't an issue with just that outlet???
 

Last edited by dlgobeavs; 10-29-08 at 02:45 PM.
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Old 10-29-08, 02:52 PM
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did you connect the neutral in the romex to the AFCI breaker and the curled neutral from the AFCI breaker to the neutral bar in the panel?
 
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Old 10-29-08, 03:00 PM
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Have you tried a load other than the TV? How about just a simple incandescent lamp? We have to rule out the TV as causing a nuisance trip. This sort of problem can be caused by a wire which was stapled too tight or box clamp which is too tight. Unfortunately that fix usually requires some drywall removal, but before we get to that point make sure you:

* verified the problem with a couple different types of loads
* verified that the lamp/tv does work in some other receptacle(s) on this circuit
* verified that the problem only occurs at or after a specific receptacle
* check the connections at the last working receptacle as well as at the first non-working receptacle
* verified the problem with a "known-good" AFCI breaker
 
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Old 10-29-08, 03:02 PM
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Originally Posted by thinman View Post
did you connect the neutral in the romex to the AFCI breaker and the curled neutral from the AFCI breaker to the neutral bar in the panel?
Yes... that is exactly how I wired it.

The thing works fine as long as the TV isn't plugged in.

I can plug other things into the plugs... and it doesn't trip.
 
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Old 10-29-08, 03:08 PM
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Plug the TV into another outlet on the same circuit and see what happens.
 
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Old 10-29-08, 03:09 PM
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Originally Posted by dlgobeavs View Post
The thing works fine as long as the TV isn't plugged in.

I can plug other things into the plugs... and it doesn't trip.
This is leaning toward a nuisance trip caused by the TV. Is it an HD tv with over-the-air receiver? I have heard of the high-frequency interference produced by HD receivers causing nuisance trips of GFCI circuits (not AFCI) but it could be the issue.

One more test I would recommend is to test each receptacle with a 1500W space heater or hair dryer if you have access to one. These appliances place a high current load on the circuit which should cause the AFCI breaker to trip if you have a broken wire or loose connection. If this test passes, I would be certain in placing blame on the TV itself.
 
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Old 10-29-08, 03:23 PM
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3:20pm update:

I have confirmed that a vacuum on any outlet blows the circuit... so it looks like it is not my TV.

If there is no heavy load... the circuit functions just fine.

Would this indicate a problem with the breaker... or still a problem with the outlet wiring?

If I have 8 outlets numbered 1-8...8 being the furthest from the breaker...if I plug the vacuum into #1... and it blows the circuit... could it still be a problem with numbers 2-8?
 
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Old 10-29-08, 03:59 PM
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Here's some helpful info.

http://www.us.squared.com/us/squared/corporate_info.nsf/unid/9CB09A222974952E85256F19005EAE4F/$file/VacuumFAQ0502homeowner.pdf
 
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Old 10-30-08, 05:10 PM
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Does anyone have any other input? At this point I am using a regular breaker vs the AFC that is required.

Is this a big issue?
 
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Old 10-30-08, 09:43 PM
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It will be nice if you tell us what state you are in due some of the states do required full AFCI and some do have partail AFCI { bedroom circuits only } and few states have none required.

What brand breaker you have on there now ??

Merci,Marc
 
  #18  
Old 10-31-08, 06:51 AM
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dlgobeavs, how hard did you drive your staples?
 
 

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