12/2 or 12/3 NM Cable?

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kwired

Electron manager
Location
NE Nebraska
Agreed... I was just wondering if there was any wiring advantage to either switch first or box first as far as conductor fill or cable runs.

To answer your question, there are devices such as occupancy sensors, dimmers, etc that require stand-by power which needs a neutral. In the past these just used the EGC for the neutral power. They draw very little power and the thought was it was ok to use the EGC for the neutral. Now (2011 and later) a real grounded/neutral is required for these devices. This is to keep unwanted current off the EGC and any metallic paths.

Edit: Even though a standard SP switch is installed, the thinking is one of the devices may be installed later and they want the neutral to be there if needed.
We also need to mention there is exceptions that don't require the grounded conductor to be there if it is a raceway wiring method or is constructed in a way that it allows easy access to later install the grounded conductor should it be needed.

This also only applies to lighting loads supplied by a general purpose branch circuit that utilizes a grounded conductor, in general that means it only applies to switches for 120 volt lighting or 277 volt lighting, but there could be other somewhat unusual circumstances where it would apply.
 

mwm1752

Senior Member
Location
Aspen, Colo
There have always been 10 ways to skin the cat -- no real advantage as everyone seems to have their own particular method -- which ever cable suits your wiring method is the most advantageous
 

Little Bill

Moderator
Staff member
Location
Tennessee NEC:2017
Occupation
Semi-Retired Electrician
We also need to mention there is exceptions that don't require the grounded conductor to be there if it is a raceway wiring method or is constructed in a way that it allows easy access to later install the grounded conductor should it be needed.

This also only applies to lighting loads supplied by a general purpose branch circuit that utilizes a grounded conductor, in general that means it only applies to switches for 120 volt lighting or 277 volt lighting, but there could be other somewhat unusual circumstances where it would apply.

I already mentioned the exceptions in post #11.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
To answer your question, there are devices such as occupancy sensors, dimmers, etc that require stand-by power which needs a neutral. In the past these just used the EGC for the neutral power. They draw very little power and the thought was it was ok to use the EGC for the neutral. Now (2011 and later) a real grounded/neutral is required for these devices. This is to keep unwanted current off the EGC and any metallic paths.

Edit: Even though a standard SP switch is installed, the thinking is one of the devices may be installed later and they want the neutral to be there if needed.
It is important to note that it was the designers/manufacturers of the occupancy sensors and other "powered" switching devices and the UL standard that was putting the current on the EGC.

This rule was not triggered by electricians trying to use the EGC as a grounded conductor.
 

Little Bill

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Location
Tennessee NEC:2017
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Semi-Retired Electrician
It is important to note that it was the designers/manufacturers of the occupancy sensors and other "powered" switching devices and the UL standard that was putting the current on the EGC.

This rule was not triggered by electricians trying to use the EGC as a grounded conductor.

Yep, I didn't get into all that when I posted to try and answer the question and keep it short and to the point.

I do know that the rule was just a concession between the NEC and UL, and not the electricians that were the reason for the code.
 

kwired

Electron manager
Location
NE Nebraska
Yep, I didn't get into all that when I posted to try and answer the question and keep it short and to the point.

I do know that the rule was just a concession between the NEC and UL, and not the electricians that were the reason for the code.
I thought the rule change was just so we would have something to complain about on internet forums:)
 

kwired

Electron manager
Location
NE Nebraska
Never heard the term California Travelers :D
Sometimes also called a California three way or a Chicago three way, or maybe a few other names but those are both common names for a set up where you supply two three way switches with both circuit conductors (connected to the "traveler" terminals and then bring the "common" terminal from each switch to the controlled load. Biggest problem with using this arrangement with an Edison base lamp is that it reverses polarity to the load to control it, and this leaves the shell of the lampholder being connected to the ungrounded conductor depending on the switch positions which is the code violation that primarily prohibits using this method.
 

ActionDave

Chief Moderator
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Location
Durango, CO, 10 h 20 min from the winged horses.
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Licensed Electrician
Sometimes also called a California three way or a Chicago three way, or maybe a few other names but those are both common names for a set up where you supply two three way switches with both circuit conductors (connected to the "traveler" terminals and then bring the "common" terminal from each switch to the controlled load. Biggest problem with using this arrangement with an Edison base lamp is that it reverses polarity to the load to control it, and this leaves the shell of the lampholder being connected to the ungrounded conductor depending on the switch positions which is the code violation that primarily prohibits using this method.
California travellers just means you use 12-2 or 14-2 romex for your travellers in a three way switch. It's code legal. The old Carter or Chicago three way is not the same thing.

 

grizwald

Member
Location
California
As far as I know California Travelers are only standard practice in California. There are a few Californicators that try to bring this style of wiring into my state; they are dealt with on a case by case basis.

That's kinda funny because, here in California we refer to that type of wiring as a "Colorado 3-way" :p
 
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