404.2 C

[Eddie702]

Two 3 -way switches one at the bottom of a stairway and one at the top both locations will require a neutral in the switch box correct? Because you can't see the upper level from the switch at the bottom of the stairs. The lower switch at present has no neutral and the upper switch does and the power to the switches is from the upper level so the bottom switch is a switch loop without a neutral.

If I can't replace the 3 wire cable to the lower switch with a 14-2-2 then my alternative would be to feed power into the lower switch from the basement and disconnect the existing feed from the second floor which would give me a neutral in both switch boxes

 

[retirede]

What is meant by “upper level?” If the lighting is for the stairs, you just need to see the stairs from both switc locations.

 

[Elect117]

"Where multiple switch locations control the same lighting load such that the entire floor area of the room or space is visible from the single or combined switch locations, the grounded circuit conductor shall only be required at one location."

The way I read it:

So long as the entire stair case is visible from both locations, the neutral is only needed in one location. So like if were talking in a commercial staircase and you had a floor skipped, and the switch was on floors 3 and 1, then you would need the neutral in both because you can't see the floor area on the 2nd floor from either switch location.


P.S. You have an exception to the rule for retrofitting.

 

[wwhitney]

So long as the entire stair case is visible from both locations

The wording is a bit convoluted, but I believe the intention is that for the collection of switch locations that have a neutral, the floor area visible from each of those switch locations combines to cover the entire floor area.

So with two locations, if one location has the entire floor area visible from it, it suffices to have a neutral at that switch location. With three locations, if none of the two switch locations provide visibility to the entire floor area, but two of them combined do, then you could just bring a neutral to those two locations and skip the third. Etc.

This would make sense if the goal is to allow the easy future installation of, among other things, occupancy sensor(s) that require a neutral and that would provide coverage of the entire floor area.

And I think the wording is compatible with this interpretation.

Cheers, Wayne

 

[Eddie702]

The location starts with a staircase from floor 1 to floor 2. At the top of the stairs there is a bedroom. The switched light lights the staircase and the bedroom (2) lights.

From the bottom switch location, you can only see the stairs. From the upper switch location, you can't see the stairs only the bedroom.

So I think I need a neutral at both locations. No big deal I can make it work.

404-2-C says: "Where multiple switch locations control the same lighting load such that the entire floor area of the room or space is visible from the single or combined switch location., the grounded circuit conductor shall only be required at one location."

My interpretation is that if you can't see the entire floor area from both switch locations you need a neutral at both switch locations.