This circuit has several receptacles and lights that are in a loop to two breakers. I understand that. However, there is a hallway with two lights, served by two 3-way switches. It works just like it should - either switch can turn on and off both lights. However, one CB turns off one light and the other breaker turns off the other light. I looked at the switches and they are really 3-way switches. There is a three conductor cable (red/black/white) going to each 3-way switch. How is this possible? I cannot draw a circuit diagram that could accomplish this feat!
Impossible 3-way light switch situation
- Thread starter scantey
- Start date
- Status
- Occupation
- Licensed Electrician
Look for a lighting contactor somewhere.
Knuckle Dragger
Master Electrician Electrical Contractor 01752
- Location
- Marlborough, Massachusetts USA
- Occupation
- Electrical Contractor
Quick guess. If not a contactor which makes the most sense.
I haven't drawn it out.Maybe a common neutral??
I haven't drawn it out.Maybe a common neutral??
ptonsparky
Tom
- Occupation
- EC - retired
Common neutral is my first thought as well. They are switching it.
drcampbell
Senior Member
- Location
- The Motor City, Michigan USA
- Occupation
- Registered Professional Engineer
Was it originally a two-family residence, built before 1940?
It was common to have two lamps in common hallways, stairwells and porches, each serviced by one family's fusebox and meter. Apparently, it was important to assure that each family had total control over their electric bill.
As for how it's wired? Chicago style is one possibility.
It was common to have two lamps in common hallways, stairwells and porches, each serviced by one family's fusebox and meter. Apparently, it was important to assure that each family had total control over their electric bill.
As for how it's wired? Chicago style is one possibility.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
That was my initial thought. There is no way to do it unless something was amiss. The chicago 3 way is a great example of how it is possible
Knuckle Dragger
Master Electrician Electrical Contractor 01752
- Location
- Marlborough, Massachusetts USA
- Occupation
- Electrical Contractor
I never knew there was a name that
What came first that or thick pan pizza
.
What came first that or thick pan pizza
.
Chicago 3-ways use only one circuit and the switches toggle the hot/neutral. Intended to utilize just 3 wires for both switching and maintain constant power at both ends.
I never knew there was a name that.
Other monikers include Carter, California, Farmer, Handyman, Illinois, Power Beyond, Homeowner, DIY, Hot-wired, Husband, Three-Wire-Hot, Switchback, and my personal favorite, Who-cares?-It works,-and there's-no-inspection!.
drcampbell
Senior Member
- Location
- The Motor City, Michigan USA
- Occupation
- Registered Professional Engineer
Chicago-style pizza is stuffed, not merely thick.... What came first that or thick pan pizza
When? Can't say. They both existed when I first became aware of words, pizza and wiring.
Knuckle Dragger
Master Electrician Electrical Contractor 01752
- Location
- Marlborough, Massachusetts USA
- Occupation
- Electrical Contractor
Very good! I think this has to be it. Of course, using contactors could do it, but I'm sure there are none of those in this house. And this is a single dwelling built in 1967.
Thanks for all the replies. That was quick!
drcampbell
Senior Member
- Location
- The Motor City, Michigan USA
- Occupation
- Registered Professional Engineer
Chicago 3-ways use only one circuit and the switches toggle the hot/neutral. Intended to utilize just 3 wires for both switching and maintain constant power at both ends.
If we had adopted 2-pin lightbulbs, like the German schutzkontakt receptacle, that wouldn't be unsafe.
Or if you used a relay to control the garage light.
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