Re-wire of two bedrooms with new electrical

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  #1  
Old 01-05-16, 02:46 PM
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Re-wire of two bedrooms with new electrical

so i currently have two bedrooms down to the studs. The electrical is old wiring and has no grounds. so i want to re-wire the bedrooms with all new outlets/wiring. the previous owner had installed two 220v outlets in the house and a single 120v outlet that i will be eliminating.

so what they did was run some metal conduit (3/4") from the main breaker panel down into the crawl space with 9 12awg THHN wires inside to a metal junction box in the crawl space. from the metal junction box its splits with romex NM wire that feeds the 220v outlets and that one single 120v outlet.

my plan is to eliminate the the outlets they installed and from the same junction box feed two new lines of NM wire for the bedrooms. i plan to put all outlets from one room on a single 20 amp breaker and all outlets from the other bedroom on another breaker. i plan to use the same THHN wires that are already in the conduit to feed the rooms. Does that sound right? is the way they ran thouse outlets from the panel correct?

Also, there are 2 orange, 2 yellow, 3 white, 1 black, 1 green wire in that conduit. can i use the 1 green wire that is in there for ground on both bedrooms?

thanks
 
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  #2  
Old 01-05-16, 02:55 PM
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The green wire may only be and must be used for the ground. The one green is sufficient for all the circuits use the wires in that conduit and may be teed off at junction boxes as needed.

The white wires may only be and must be used for neutrals.

Example of usage:

One yellow and one white for branch circuit #1

One orange and second white for branch circuit #3

Other yellow, other orange, third white for a combination 120/240 volt circuit (double wide two pole breaker in slots #2 and #4) aka multiwire branch circuit giving two allotments of 20 amps at 120 volts.

A MWBC can split off as two "regular" subcircuits treated as ordinary 120 volt circuits, foregoing any 240 volt capability beyond that point. It still needs a double breaker with handles tied, and positioned to have 240 volts between the two breaker poles.
 

Last edited by AllanJ; 01-05-16 at 03:20 PM.
  #3  
Old 01-05-16, 02:58 PM
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Hi, yes that will work with the exception of the Orange and Yellow conductors,remove one and install a White conductor,also you will need to use AFCI breakers.
 
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Old 01-05-16, 03:22 PM
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Oops, I forgot about the black wire, you can use your imagination as to how to use it, for example two MWBCs and one regular circuit (black and white) out of the panel.
 
  #5  
Old 01-05-16, 03:32 PM
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I don't know if I would "waste" 2 20amp circuits on only 2 bedrooms. Do you have plenty of space in the panel for future use?
 
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Old 01-05-16, 03:46 PM
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Awesome. Just making sure I'm not in any code violations. Some of the codes arent very clear.

So is there any benefit of wiring it as a multi wire branch circuit other then a 220v capability rather then just using a single breaker for each circuit?
 
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Old 01-05-16, 03:50 PM
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There are a few breakers I can eliminate for future use. There will be two spots open from the other 220v outlet I'm going to cancel and a couple other breakers that I can eliminate.
 
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Old 01-05-16, 03:57 PM
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If you aren't improving more that 50% of the house then it is not mandatory to install arc fault breakers. However, arc fault breakers are a good idea and if you do go that way..... each circuit requires its own neutral. No MWBC wiring with arc faults.
 
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Old 01-05-16, 04:23 PM
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The 50% rule might be a local rule. If I were to install a new circuit here it would require AFCI protection.

The problem with a MWBC is that 2 pole AFCI breakers are not available for all panels.
 
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Old 01-05-16, 04:46 PM
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So is there any benefit of wiring it as a multi wire branch circuit other then a 220v capability rather then just using a single breaker for each circuit?
The MWBC can share a neutral, the individual breakers cannot.
 
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Old 01-05-16, 05:03 PM
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Just curious, what code article is that 50% rule?
 
  #12  
Old 01-05-16, 05:23 PM
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Hmm I see. Now I'm not sure what to do whether to wire it up as a mwbc or just individual breakers. Also, looks like the arc fault breakers take up more space on my panel then my regular single breakers. Takes up the space I thought I could free up. So many options.
 
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Old 01-05-16, 05:28 PM
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AFCI's aside.
Maybe the MWBC is the way to go for the bedrooms, get it out of the way now. You can share the neutral and label the double pole breaker "bedrooms".
 
  #14  
Old 01-05-16, 06:11 PM
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The afci will take up the same space as a regular breaker.
 
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Old 01-05-16, 06:23 PM
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Also, looks like the arc fault breakers take up more space on my panel then my regular single breakers
Sure those aren't tandem (half size) breakers you are looking at.
 
  #16  
Old 01-05-16, 06:36 PM
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Well some of my single ones look like they are half inch wide.. which is what I was thinking of putting in but I didn't swe any arc fault ones that wide. I'll have to double check at the store what they have
 
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Old 01-05-16, 07:15 PM
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Well some of my single ones look like they are half inch wide
Please post a picture of your panel with the cover removed. If they are tandems your panel may have a limit on the number of tandems. Please post the make and model number of your panel.
 
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Old 01-06-16, 04:24 AM
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Sounds like you have tandems. If so, you will not find and afci to fit in that space. They are all full width.
 
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Old 01-06-16, 04:37 AM
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I I will post pictures when I get a chance today.
 
  #20  
Old 01-06-16, 05:02 PM
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here is a photo of my panel. Pretty old made by Crouse Hinds. I could not find a model number the lettering is mostly gone.
Name:  panel3.jpg
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  #21  
Old 01-06-16, 06:26 PM
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Except for the double pole breakers they all look like tandems. An afci will take the place of one tandem.
 
  #22  
Old 01-06-16, 07:36 PM
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Those aren't tandems. Crouse-Hinds made 1/2" breakers that had to be used in pairs. They each had a hook that slipped over the bus stab. Each of the breakers in the pair had a slightly different catalog number because the hooks on each were slightly offset. I'd take this opportunity to replace them with Eaton/Cutler-Hammer non-CTL tandem breakers.
 
  #23  
Old 01-08-16, 07:23 PM
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OK so if I go with a mwbc...do I need to pigtail the neutrals at all my outlets when Daisy chaining them?


Also, if I just run both bedrooms from a single 20 amp breaker there will be a total of 12 outlets on that circuit. I don't anticipate using all outlets at the same time and I don't think I wi reach 20 amps with normal bedroom stuff. All I will need to do is Daisy chain all 12 outlets together correct?

Thanks for all the info I am just trying to better understand different options.
 
  #24  
Old 01-09-16, 04:45 AM
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Pigtails are the best option,or you could use a single 20 Amp circuit,I usually do pigtails of all my connections at outlets then I only have to make single connections on the outlets.
 
  #25  
Old 01-09-16, 07:06 AM
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The neutral pigtail wou ld only need to be pigtailed where both circuits were in the same box. Once it splits it is a single circuit .
 
  #26  
Old 01-18-16, 04:17 PM
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I have been looking through the code book but can't seem to find what I read in a forum somewhere. I read that when the supply power is at the light source and i install a switch that the switch must have a neutral wire in the switch box even though it won't be used? I understand I would probably need it for certain dimmer switches but is it code that a neutral wire must be present in there.

Thanks
 
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Old 01-18-16, 04:24 PM
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I read that when the supply power is at the light source and i install a switch that the switch must have a neutral wire in the switch box even though it won't be used? I understand I would probably need it for certain dimmer switches but is it code that a neutral wire must be present in there.
Yes, unless it can be easily added at a later time such as when conduit is used.
 
  #28  
Old 01-18-16, 04:59 PM
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Thanks seems like a waste for the closests but oh well.
 
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Old 01-19-16, 06:25 PM
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I read that when the supply power is at the light source and i install a switch that the switch must have a neutral wire in the switch box even though it won't be used?
That requirement first appeared in the 2011 code. What code is your city on?
 
  #30  
Old 01-19-16, 06:53 PM
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I believe 2013. At least that's what I seem to find online for the Los Angeles area.
 
  #31  
Old 01-20-16, 07:50 PM
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So I just wired up my lights and noticed something somewhat strange.

I have a light that has power coming into it from a 12/2 wire...from the light it goes to a switch with 12/3. The switch is not connected yet but I am getting 24v AC on the red wire with out either end of the red connected anywhere yet. Normal?
 
  #32  
Old 01-20-16, 09:09 PM
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If you are using a digital multimeter it is meaningless "ghost" voltage. It is why we recommend an analog multimeter. The very low natural impedance of an analog multimeter bleeds off the ghost voltage. Digital meters with out special circuits will show it as real voltage.

http://support.fluke.com/find-sales/...105317_A_w.pdf
 
  #33  
Old 01-21-16, 09:44 AM
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I believe 2013. At least that's what I seem to find online for the Los Angeles area.
The NEC is updated every three years, the next version after 2011 is 2014. LA may have their own codes modeled after the NEC updated annually.
 
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