404.2 C 2
- Thread starter ceb58
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kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
The confusion is over the fact the lighting circuit does not have a grounded conductor but the control circuit does. Not sure we entirely know the intent in this instance, but by making the control circuit not have a grounded conductor should remove all doubt, how do you run a grounded conductor with a circuit that does not have one, and have any useful purpose for said conductor?
- Location
- Illinois
- Occupation
- retired electrician
I don't think that there is any real question as to the intent of the code change. It was made so that UL would change their standard for occupancy sensors and other electronic switching devices to prohibit these devices from using the EGC as a grounded conductor. The intent of the code would require the grounded conductor for the switching circuit to be in the switch box, but the code wording does not support that intent.
- Occupation
- Licensed Electrician
The way I see it the intent of the of the rule is to require a grounded conductor at each switch or make it possible to add one without making a big mess on the carpet or finished walls; if all the wiring is exposed then that is doable.
- Location
- Illinois
- Occupation
- retired electrician
Yes, if you can easily add a grounded conductor after the original installation then you don't have to provide one at the time of the original installation. My point is that the rule requires you to provide a grounded conductor for the lighting circuit, and not for the lighting control circuit if one is used. If there is a lighting control circuit, there is no use for the grounded conductor of the lighting circuit to be at the swich location.
The intent is that the grounded conductor that the switch uses (even when that is not the same grounded conductor as the lighting circuit uses) is to be at the switch location, but the code wording does not say that.
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
I understand that, they did include mentioning if the circuit contains a grounded conductor, they did not mention circumstances where the lighing is controlled via a separate control circuit.
Personally, I think this is a design issue and should not be a NEC requirement. If you later want to add an occupancy sensor and it needs a grounded conductor - you need to add a grounded conductor. If you knew there was a good chance of needing a grounded conductor and installed one - well then installing the occupancy sensor just became easier. If UL decides it is safe to carry necessary current on EGC then it is a UL issue not NEC issue.
- Location
- Illinois
- Occupation
- retired electrician
It is a safety issue for someone working on the EGC. Workers do not treat the EGC as an energized conductor and that is what it becomes when it is used as the grounded conductor for the electronics.
UL does not get to change the code, but the issue here is that they were not changing the code when they permitted the EGC to be used as a grounded conductor. I had thought, before this issue came up, that the code had a rule that said you could not use the EGC as a grounded conductor, but there really isn't a rule that actually says that.
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
No rule that actually says you can use EGC as a grounded conductor may be true, yet there is requirements that a separate grounded conductor must be run when needed. UL maybe was just plain wrong in first place to allow EGC to carry this small current, that seems somewhat harmless, but like has been said, put enough of them on same circuit and now you have a significant amount of current on that EGC.
Evolution of new products does make for necessary code changes sometimes. I just feel the change was not needed in the first place because the EGC should never have been allowed to be used this way. There have been photo controllers, timer controllers, and other devices around for years that used a grounded conductor and was never acceptable to use the EGC for this purpose with those devices. The problem has come up more recent years with low current control devices and UL deciding it is safe if the current is below a certain level. Now put several of these devices on a feeder and you have an EGC for that feeder carrying a level of current well above the level deemed safe for just one device.
- Location
- Illinois
- Occupation
- retired electrician
but my point is that there is no specific rule that says you can't.
jwelectric
Senior Member
- Location
- North Carolina
404.2 Switch Connections. (A)
Three-Way and Four-Way Switches.
Three-way and four-way switches shall be wired so that all switching is done
only in the ungrounded circuit conductor. Where in metal raceways or
metal-armored cables, wiring between switches and outlets shall be in accordance
with 300.20(A).
Exception: Switch loops shall not require a
grounded conductor.
Three-Way and Four-Way Switches.
Three-way and four-way switches shall be wired so that all switching is done
only in the ungrounded circuit conductor. Where in metal raceways or
metal-armored cables, wiring between switches and outlets shall be in accordance
with 300.20(A).
Exception: Switch loops shall not require a
grounded conductor.
- Location
- Illinois
- Occupation
- retired electrician
This will be addressed in new Exception #3 for the 2014 code. The grounded conductor will only be required at one switch location where there are multiple switches that control the same light(s). It often takes two or 3 cycles to get a code change correct and to get it correlated with other code sections.
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
I didn't look around for any specific rule myself, and I do believe you and am not suprised, even though it goes against what we were all taught - to almost always separate current carrying grounded from equipment grounding conductors.
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