3 way switches

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roger3829

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Location
Torrington, CT
iwire said:
Dennis 200.7(A) says you can only use white for the grounded conductor, then 200.7(C)(2) says you can use the white for the supply to the switch.
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200.7(c)(2) says...... it can be used to supply the switch but not as a return conductor from the switch to the switched outlet.

Since the wire is not connected to the switched outlet, but rather is supplying power to another switch (traveler) I don't see how this would be a violation
 
iwire

iwire

Moderator
Staff member
Location
Massachusetts
roger3829 said:
200.7(c)(2) says...... it can be used to supply the switch but not as a return conductor from the switch to the switched outlet.

Since the wire is not connected to the switched outlet, but rather is supplying power to another switch (traveler) I don't see how this would be a violation
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That is another way of looking at it.
 
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shocme

Member
Responce

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We call this a reverse feed, and it is a common practice here. In the older homes, this is all the used to do. The only thing you would have to do of course(if using romex) is identify the white conductor as a hot wire by using tape or other method.
 
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shocme

Member
We call this a reverse feed, and it is a common practice here. In the older homes, this is all the used to do. The only thing you would have to do of course(if using romex) is identify the white conductor as a hot wire by using tape or other method.
 
K8MHZ

K8MHZ

Senior Member
Location
Michigan. It's a beautiful peninsula, I've looked
Occupation
Electrician
Here is a pretty good linky for all y'all.

http://www.homeimprovementweb.com/information/how-to/three-way-switch.htm

As for re-marking the feed to the switch and not using it for a traveler, to me it makes things easier. If I see a re-marked wire, I know it has to go to the common.

I really wish that three color cable with no white conductor was readily available but around here it isn't so we pretty much have to always re-mark Mr. White to run 3 and 4 way switches. I try to use a color other than black to do so.
 
LarryFine

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
K8MHZ said:
I really wish that three color cable with no white conductor was readily available but around here it isn't so we pretty much have to always re-mark Mr. White to run 3 and 4 way switches. I try to use a color other than black to do so.
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Same here. I've often wished for 2-conductor NM with black and red, for example. I carry an assortment of Sharpies for this, rather than taping; red and blue are essential.
 
2

220/221

Senior Member
Location
AZ
One reason to keep the power OUT of the light boxes is troubleshooting.

I don't want to be taking fixtures down to check connections. Taking a switch out is WAY easier.
 
480sparky

480sparky

Senior Member
Location
Iowegia
220/221 said:
One reason to keep the power OUT of the light boxes is troubleshooting.

I don't want to be taking fixtures down to check connections. Taking a switch out is WAY easier.
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Double amen. :grin: :grin: :grin: :grin:

The only connections I would need to check at a light fixture is the light fixture itself.
 
bikeindy

bikeindy

Senior Member
Location
Indianapolis IN
roger3829 said:
200.7(c)(2) says...... it can be used to supply the switch but not as a return conductor from the switch to the switched outlet.

Since the wire is not connected to the switched outlet, but rather is supplying power to another switch (traveler) I don't see how this would be a violation
Click to expand...

I agree with this only I don't like to see the white wire used as a traveler. It is not needed as a traveler unless you are using 2 wire to make your 3ways.
 
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roger3829

Senior Member
Location
Torrington, CT
bikeindy said:
I agree with this only I don't like to see the white wire used as a traveler. It is not needed as a traveler unless you are using 2 wire to make your 3ways.
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If you have the 3-way at the end of a loop (dead end) then you have noe choice but to use the white wire. Around here the most common way 3-ways are connected is the red & white are the travellers and the black is the hot/switch leg.

Why would you wire a 3-way switch under any circumstances with a 2-wire?
 
iwire

iwire

Moderator
Staff member
Location
Massachusetts
roger3829 said:
If you have the 3-way at the end of a loop (dead end) then you have noe choice but to use the white wire.
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Yes, but you not have to use it as a traveler, use the white as the point, red and black as travlers. :)
 
iwire

iwire

Moderator
Staff member
Location
Massachusetts
480sparky said:
Point? New term to me. I say 'common' myself. :)
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That makes sense. :)

If I was talking about a regular SPDT switch I would say common. When I think 3 ways I call it a point. :-? Why? I don't know, I guess that is how it was taught to me way back when. :-?
 
bikeindy

bikeindy

Senior Member
Location
Indianapolis IN
roger3829 said:
If you have the 3-way at the end of a loop (dead end) then you have noe choice but to use the white wire. Around here the most common way 3-ways are connected is the red & white are the travellers and the black is the hot/switch leg.

Why would you wire a 3-way switch under any circumstances with a 2-wire?
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yeah what Iwire said. and I would never wire a three way with 2 wire but I have seen it done, and in that case you would use a white as one traveler. Lets remember there are at least 9 compliant ways to wire three ways none is really better than another I am with Iwire I wire them which ever is the most logical and cost effective for the location. I have been heard to say while doing some, wait till the next guy comes here he will be cursing me. Some guys have a difficult time seeing how three ways and 4 ways work and are just comfortable doing it the one or two ways they were taught. It is strange that when you try to explain electrical flow using plumbing analogies people seem to beable to visulize the working of the circuit.
I have two water heaters and they are plumbed in such away that they have 7 valves to control water flow depending on how I want to use them (one is gas the other electric) when the plumber was done he said i will show you how all that works when I finish writing up your bill. I said no need I see it, it is just a simple circuit. He said Oh yeah you're an electrician.
 
bikeindy

bikeindy

Senior Member
Location
Indianapolis IN
iwire said:
That makes sense. :)

If I was talking about a regular SPDT switch I would say common. When I think 3 ways I call it a point. :-? Why? I don't know, I guess that is how it was taught to me way back when. :-?
Click to expand...

Well a three way is a regular SPDT switch it is just that it has a dumb name when used in residential or commercial applications.
 
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