3 way wiring by code

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Well I guess it's cause I'm just use to doing it a certain way cause the client likes it that way, but at the ceiling Joint box, we use a 3/4" EMT or 1" down
to the switch box, one likes Purple travelers, another likes red travels. Go figure ...
 
brantmacga said:
Page 111 - 250.118(10) says the metallic sheath of MC cable may be used for EGC.
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250.118(10) ['05] states:
Type MC cable where listed and identified for grounding
in accordance with the following:....
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The commentary following 330.108 in the '05 NECH states:
The armor of interlocking Type MC cable is not usually recognized by UL as the sole means of providing an equipment grounding circuit, but it may be used to supplement the internal grounding conductor.
A new construction where an aluminum equipment grounding conductor within a multiconductor cable is in continuous contact with the aluminum interlocked armor has been approved by UL to serve as the equipment grounding conductor.
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250.118(10) ['02] is MI cable ....moving onto 250.118(11):
Type MC cable where listed and identified for grounding in accordance with the following:
Click to expand...
The commentary following 330.108 in the '02 NECH states:
The armor of interlocking Type MC cable is not recognized by UL as the sole means of providing an equipment grounding circuit but may be used to supplement the internal grounding conductor.
Click to expand...

NOTE: While the commentary is NOT enforceable, it does provide usefull guidance to the user.


brantmacga said:
330.24 mentions a smooth-sheath and an interlocked corrugated type sheath. i've never seen smooth sheath MC cable, so is the corrugated type the AP you're talking about?
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(330.24? ...bending radius)

The "new" MC-AP looks like this;
cableboxes.jpg

No "green wire", the sheath is listed and identified as an EGC.
http://www.southwire.com/processGetPage.do?bp=featuredProduct.jsp
 
oh okay. so only if it has no green wire is it listed as egc.

Pigtails aren't required on switches used with metal boxes. And don't you guys use self-grounding receptacles?
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that was my point. its not required by code, but required by ahj.
 
brantmacga said:
oh okay. so only if it has no green wire is it listed as egc.
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I don't know that I would live by that opinion....some "creative" types might decide to ust snip off that pesky green wire ~ TA DA! MC-AP!

"Listed and identified" are the ways to determine.


Maybe someone can explain to me the difference:
AC vs. MC vs. MC-AP?
(...and does the "AP" mean "All-Purpose"? :) )
 
3 way

3 way

I personally would use the 2 white wires as the point wires AKA the feed to the first 3 way and the load to the light from the second 3 way. I would use the black and the red as my travelers throughout to keep some sort of consistency to the circuit.
 
stickboy1375 said:
I don't use tape, I normally drill a hole in a sharpie tip and insert the wire thru the hole in the sharpie to re identify it...
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this sounds like a good idea. For those who feel the need to break your chops about wire size they could drill 2 different sized holes 90 degrees apart to solve thier sizing problems. And if two sizes arent enough 120 degrees apart will give you 3 sizes.
 
winnie said:
Why can't all of the color coding requirements be tabulated in _one_ location. :)

Although to be fair, the 250.119 requirement that Don quoted is _not_ in the 2002 code.

-Jon
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Jon, in the 2002 cycle 310.12(C) had it covered. :smile:

Roger
 
iwire said:
Much easier then tape or sharpie, I just don't remark them at all. :D
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Thanks Bob, I remember a good thread about this a while back. :grin:

Roger
 
quogueelectric said:
I personally would use the 2 white wires as the point wires AKA the feed to the first 3 way and the load to the light from the second 3 way. I would use the black and the red as my travelers throughout to keep some sort of consistency to the circuit.
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I thought this would be a violation of art. 200.7(C)(2)
 
prior to the 99 code the white wire feeding the switch was not required to be identified as an ungrounded conductor however the white return leg to the load was required to be identified after 1999 the required reidentification must be efective, permanent, and suitable for the environment, to clearly identify the insulated conductor as an ungrounded conductor. Yes they would in fact need to be reidentified I thought that was understood.
 
3 way

3 way

What is the definition of a cable assembly is it a reloc manufacured cable assemly or is it a piece of mc cable going from jbox to switch box. In this particular installation where is the feed and the load to the light. I am going to assume that the feed and the load are also going to be in this box so the wire to the outlet/fixture will be the proper colors.
 
quogueelectric said:
What is the definition of a cable assembly is it a reloc manufacured cable assemly or is it a piece of mc cable going from jbox to switch box. In this particular installation where is the feed and the load to the light. I am going to assume that the feed and the load are also going to be in this box so the wire to the outlet/fixture will be the proper colors.
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Cable assembly can be mc in this case or it can be nm or other approved assemblies

What matters is the switch leg back to the light cannot be the white wire even if you mark it.
 
the final leg is in 2 separate parts switch to jbox and 2 wire to light. This is a very unusual installation however I have seen it done this way occasionally.
 
quogueelectric said:
the final leg is in 2 separate parts switch to jbox and 2 wire to light. This is a very unusual installation however I have seen it done this way occasionally.
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Still digging. :grin:

Roger
 
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