Hi just found this site and it looks to be a great help. I have an old house built in 1959 and I have made some corrections in my time here but some of the stuff I am getting into now is over my head. I think I need an electrician but I thought I use this forum in the future to guage whether I need to seek a pro or not with some of the stuff I am encountering.

Heres the latest problem.

I replaced an old light fixture yesterday (23W). I noticed that the fixtures return is pigtailed to a larger five wire splice of neutrals. The thing that is confusing is the fixture switch leg is supplied by a different circuit than the one the neutrals serve as the return for.

The ceiling box also had ungrounded wires on a different circuit than the one the switch leg is supplied from.

I am guessing that the two circuits in the box are not part of a multiwire branch circuit though. The two circuits in question are on the same phases where the rest of the traditional wired MWBC in my house are on opposite phases.

Is this something that needs to be addressed? Or is otherwise uncommon in an old home?

 

How many conductors (or wire ends) and how many cables come into the switch box and how are they arranged?

How many conductors and how many cables come into the light fixture box and how are they arranged?

If power comes up to the light from the switch and was not fed from the switch box, it should be accompanied by a neutral from the switch box. Only this hot and this neutral should be connected to the light.

This alternative is also often found. Power really comes only to the light box. One cable sends the power down to the switch and back up to the light. In this case the light fixture white wire or silver screw may be connected to a cluster of neutrals that serve other branches that the single incoming power wire serves. Correctly, the black wire in the cable going to the switch brings the power back to the light.

If two power cables, each with its own required neutral, come into the same box then they must have separate clusters of neutrals respectively for the downstream subcircuits they serve. This is required even if the two power feeds came from what was a multiwire branch circuit or even if the two power feeds branched off of the same ordinary circuit upstream and came back together in this box. Where one power feed finds its way up to the light via a switch box and another power feed enters the light box directly to serve everything else in or continuing from that box, this counts as two power feeds entering the (light) box requiring separate neutral clusters.

For ground wires it's different; all go into one cluster in the box. If there are too many for one wire nut, multiple (usually green) wire nuts can be used with short lengths (pigtails) connecting these "subclusters."

 

What you describe sounds very non typical. How did you determine the hot was not associated with the neutral?

 

I will try to describe whats in this ceiling box, the switch box below and some fixtures close by. But I doubt we can make much sense of this here......

The ceiling light is controlled by 2-3W & 1-4W. And is on a different circuit then the other lights in this equation.

There are 5 conduits entering the ceiling box.

1. Orange (hot connected to fixture, not spliced in box is in box in basement with 4 way switch), Red, Yellow and White
2. Red / White
3. Red / White
4. Yellow / White
5. Yellow / White

The 3 reds are spliced (only hot when switched). 3 yellows are spliced (constant hot) and 5 whites are spliced with additional pigtail for ceiling fixture.

Theres a 2 gang switch box below that has a 3 way switch that controls the ceiling fixture (part of the 4W combo) and another 3 way that controls outdoor lights. Theres a small bathroom next to this hallway that has a single pole switch that controls a pair of vanity lights.

There are 4 additional lights in close proximity to the ceiling box.

2 outdoor lights (controlled by the same 3 way switch) and 2 vanity lights that (controlled by a single pole in different box).

The outdoor boxes only have a two wires in each. I believe they are red and white

The vanity lights:

box 1: 2 conduits (Y/W) and (Y/R/W) box 2. 2 conduits (Y/R) and (Y/R/W)-- Red are the switch legs in both boxes and the yellows are constant hot.


Bottom line and back to my initial description.

The ceiling light is controlled by the Orange (switch leg) in the ceiling box. That gets its power from a different circuit than all the other lights I described. However, the return to that fixture is tied in with the neutral splice. So does that mean its overloaded? (by just the wattage of the fixture?)

I probably have not made an inch of sense but if you can decipher any of this I sure would appreciate your opinion and can provide you with any other information needed to sort this out......

FWIW- Theres is no issue with the lights, everything works?

 

Do you need to turn off more than one breaker to remove all the power from the junction box?

 

Yes, the hot to the fixture is switched, and is on a different breaker. Both breakers are on the same leg of the panel.

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Here is the switch boxes, im sure it will just confuse the matter here though:

2 gang switch box.
1 3W controls outdoor lights (2 Reds travelers + yellow common)
1 3W controls ceiling fixture in question, part of 4W setup, 2 yellow travelers + black common)

There are 3 conduits going into switch box that contain
1- yellow, white, red, orange
2- from basement closest to panel has 2 black, 2 red, yellow orange
3. yellow, white

2 yellows are spliced
2 oranges spliced
2 whites spliced
1 black (I think is power in) is spliced to 1 red (red from 1st conduit)


----------------------
The vanity switch just has red switch leg and yellow power in.
----------------------

I haven't taken apart the 4W or the other 3W.


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Bottom line, that ceiling fixture return is pigtailed with the returns being used on the other circuit. I believe this is all lighting. The fixture is 23W. Its likely been working like this for 50+ years, should I be messing around with this at all?

 

The neutral should be run with the associated hot. Something still does not sound correct. Maybe I am not understanding your setup.

 

It appears there is a white run in the same conduit with the orange switch leg to the fixture. However its spliced in the ceiling box with the neutrals for the other lights on the other circuit.

So if that was the case, does it need to be fixed and why?

and again, its been functioning like this for 50+ years... should I concern myself with this?

 

I'm having a bit of trouble following but it sounds like to separate circuits in the box and at some point the two neutrals of each circuit were connected together. The two neutrals need to be disconnected. By code neutrals on separate circuits can't be connected together.

 

With both breakers on the same hot leg of the panel the neutral will carry up to 2x the current as the hots.

 

So that means the neutral on the other circuit than the ceiling fixture is overloaded by the ceiling fixture wattage of 23W?

Since its been like this for 50 years, should I be calling an electrician to sort this out?


Yes, but its not the entire circuit... Im thinking its just the fixtures neutral that is tied into the other circuits return.

I am probably missing something but if its is indeed like this, Is this something that can wait to be corrected?

 

I know diagnosis over the internet, esp with the nest of wires I am describing, is impossible.... but I am trying to guage if I can hold off on this with an electrician until I have a bigger project. If I am overloading the neutral by the wattage of the fixture, how dangerous of a situation do I have here? Its been in place for 50+ years I know this for certain because of the material used to make the connections in the box.

I was going to post the wire configurations again in hopes of figuring out how the 3 ways and 4 ways were wired but I fear it will do no good, I am having trouble relaying the information to you in a coherent manner.

 

Ray2047, why are you editing my message? remove referrer?

I suppose my inquiry is beyond the scope of the DIY forum? Or am I just not making much sense?

 

Because it just clutters up the thread and is unneeded because it just links to the thread you are already looking at.

 

I see what you removed. I understand.

I would really appreciate some guidance here, we are unclear what to do in this situation.

Do I need an electrician immediately?

Its probably bad ettiquete to bump this thread like this, but I thought I would give it another shot in this forum before moving on....

 

It may take an electrician to sort it out. It could be dangerous depending on loads. It could also be a life safety issue since someone could throw only one breaker and not realize the circuit is still hot. Final derision is yours. To DIY you would need to open every box on the two breakers and look for a cross connection but it may take an electrician to spot it.

 

Perhaps your right. Its probably over my head.

Im unclear on how critical this is to get someone over here because 1. its been like this for 50 years and the light is working. and 2. I am thinking that it would only be overloaded by the wattage of the bulb.

If it was under load from the rest of the circuit, there would have to be neutral in and neutral out inside the box.... I am counting 5 neutrals pigtailed in the ceiling box with 4 fixtures.

The splice in the ceiling is also soldered, presumably original to the home, so the fixture neutral wasn't added to this splice.

The only other thing I can think of if it was done later was that power to one of the 3 way switches or 4 way switches was changed later. But I am unclear at this point where the light gets its power from.

Just kind of thinking outloud.... thanks anyway for trying.