JHZR2
Member
- Location
- New Jersey
- Occupation
- Power Systems Engineer
I know there are lots of these stories on the web, because I searched first before posti this one... Looking for recommendations on the way ahead.
Was as working in a home that is entirely wired with cloth type two conductor NM cable. It has an updated 100A service with 15A GE breakers, all looks good. Owners desired to install a three-prong outlet in each room, so the first step was to check the wiring upstairs. Essentially, two conductor NM comes up to an outlet, the continues on via that outlet and a junction box in the attic to feed a bunch more outlets as well as a few lighting fixtures. So the fix was to put in a GFCI at that first point, the from the load side everything would be protected, so the install a three prong duplex receptilce in each of the other bedrooms, properly labeled, so they had their convenience and protection. Easy, it worked, left.
Got a call back tonight because when they turned on the upstairs hallway light, the GFCI tripped and it went dark. So it turns out on the load side of the GFCI I installed, there are two, three way switch circuits that operate a light in one and an outlet on the other.
Testing things, switching EITHER of the three way circuits, i.e. The one that operates the light or the one that operates the outlet, trips the GFCI.
i took the box apart and saw this...
scary.... Two three way switches with a bunch of wires twisted (but not nutted) together, just taped and twisted up in there. I think eight conductors total.
So what's the best way ahead? Old house, not everything is accessible from the attic or basement, and who knows why people did what they did long ago. I don't like that twisted pair that isn't even nutted...
My gut feel is that some circuit, maybe the switched outlet, is fed from another source as well, and has a crossed neutral. I suppose I could have crossed neutrals on the GFCI too, though not sure why that would cause an issue with only the three way switch operations...
So so what's the best way ahead? It seems that the easiest and least time consuming, if the issue isn't immediately obvious, would be to go back to the original GFCI outlet that I installed, jumper the load to the line screws, and then just install gfcis at all positions downstream where a three prong outlet is desired. That way each three prong op ungrounded outlet will be protected by its own GFCI.
Are re there any other approaches I should consider? I will try to look for obvious points where a neutral might be crossed or wrong, and not just immediately default to the plan b GFCI in all spots option...
but it anything else I should consider when trying to solve this and track it down?
thanks!
Was as working in a home that is entirely wired with cloth type two conductor NM cable. It has an updated 100A service with 15A GE breakers, all looks good. Owners desired to install a three-prong outlet in each room, so the first step was to check the wiring upstairs. Essentially, two conductor NM comes up to an outlet, the continues on via that outlet and a junction box in the attic to feed a bunch more outlets as well as a few lighting fixtures. So the fix was to put in a GFCI at that first point, the from the load side everything would be protected, so the install a three prong duplex receptilce in each of the other bedrooms, properly labeled, so they had their convenience and protection. Easy, it worked, left.
Got a call back tonight because when they turned on the upstairs hallway light, the GFCI tripped and it went dark. So it turns out on the load side of the GFCI I installed, there are two, three way switch circuits that operate a light in one and an outlet on the other.
Testing things, switching EITHER of the three way circuits, i.e. The one that operates the light or the one that operates the outlet, trips the GFCI.
i took the box apart and saw this...
scary.... Two three way switches with a bunch of wires twisted (but not nutted) together, just taped and twisted up in there. I think eight conductors total.
So what's the best way ahead? Old house, not everything is accessible from the attic or basement, and who knows why people did what they did long ago. I don't like that twisted pair that isn't even nutted...
My gut feel is that some circuit, maybe the switched outlet, is fed from another source as well, and has a crossed neutral. I suppose I could have crossed neutrals on the GFCI too, though not sure why that would cause an issue with only the three way switch operations...
So so what's the best way ahead? It seems that the easiest and least time consuming, if the issue isn't immediately obvious, would be to go back to the original GFCI outlet that I installed, jumper the load to the line screws, and then just install gfcis at all positions downstream where a three prong outlet is desired. That way each three prong op ungrounded outlet will be protected by its own GFCI.
Are re there any other approaches I should consider? I will try to look for obvious points where a neutral might be crossed or wrong, and not just immediately default to the plan b GFCI in all spots option...
but it anything else I should consider when trying to solve this and track it down?
thanks!
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