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Joined: Mar 2001
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Does anyone see any issues with using 2 lengths of 2-conductor NM cable to a 4-way switch?
No neutral being carried to the 4-way switch. Just 2 sets of travelers.
BTW,
Would the new 4-conductor NM Cable make this more acceptable?
[This message has been edited by Redsy (edited 02-08-2004).]
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Joined: Jul 2001
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It is a lot like knob & tube wiring method I guess, only with nonmetalic boxes.
The method this contractor uses is to feed a 3 way from the nearest circuit, & grab a neutral (not necessarily from the same circuit), from another convenient nearby box.
Regarding my 1st post... he has changed to all 3wire travelers.
Rick
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Joined: Dec 2003
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Oh, I see now. That is just lazy wiring. Grab a neutral from any convenient box? No way.
Earl
Earl
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Hi Rick,
A two wire traveler, according to 404.2(a) exception is not required to have a grounded conductor ran in the same cable. I would reject the installation for grabbing another neutral from a different cicuit or require a double trip device to kill the power from the other circuit as required under 210.4(c) exception #2
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From what our NEC experts have said, it sounds as though it would be code-compliant, but I would not run travelers like this unless the wiring could be so physically arranged as to have the return conductors running adjacent throughout. It used to be pretty common in the U.K. for lighting circuits to be wired with travelers like this or with single conductors from 3-way switch to lamp and so forth (particularly in the days before grounds were required to be run on lighting circuits). Does anyone see any issues with using 2 lengths of 2-conductor NM cable to a 4-way switch?
No neutral being carried to the 4-way switch. Just 2 sets of travelers. If the two runs are bundled together throughout and run from the 4-way back to the same box for splicing into an existing 3-way circuit, then the fields should cancel out just fine.
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pauluk,
What you describe is just what I meant.
The current carrying conductors would be in different cables, but stacked together, and therefore in close proximity.
There is a 4-wire NM cable on the market over here now. If there are any concerns about the separate cables, this would seem to be the solution.
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I think Redsy is talking about a 14-2 set of travelers going to a 4 way from 3 way #1, & a 14-2 set of travelers leaving the 4 way going to 3 way #2. This is no different than the 2 wire travelers between the 3 way switches.
Mountainman, 404.2 referrs to switch loops only... not travelers. Respectfully,
Rick
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Looks like your posts crossed within a few seconds of each other. a 14-2 set of travelers going to a 4 way from 3 way #1, & a 14-2 set of travelers leaving the 4 way going to 3 way #2. This is no different than the 2 wire travelers between the 3 way switches.
Agreed. If the two cables leave the 4-way in different directions, then there will be a resultant field from the single conductor on each cable which is carrying current at any instant. That new 4-conductor Romex sounds quite handy.
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"Mountainman, 404.2 referrs to switch loops only... not travelers. Respectfully,
Rick"
If travelers are not part of the switch loop, then what are they?
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Rick, a switch loop would have current flowing in oposite directions at the same time in two conductors, thus canceling each other.
In a set of travelers, current only flows in one conductor at a time.
Roger
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