3-way switch with a twist

[Bert_]

Looking close at those pictures I don't there is any conduit. It really looks like thhn or maybe tw wire just flying in though an open knockout. If that's the case then the whole thing is one big hack job after another.

I'm just going to repeat this in hopes the op notices it among all this extremely useful discussion...

I would really like him to take a closer look.

 

[JeepJohn62]

I'm just going to repeat this in hopes the op notices it among all this extremely useful discussion...

I would really like him to take a closer look.

I agree with you. There is no safety ground shown either. This should be done properly. This is how building fires get started.

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[Terry D]

I suspect that none of the white wires are in fact a neutral. They are marked black indicating a hot traveler switched wire.

The actual neutral is probably terminated at the load. Only the hot wires and traveler returns are connected at the switch.

John

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The neutrals do run through the switches, the hot and neutral at the load, reverse every time a switch is toggled

 

[Terry D]

A "4-way" (intermediate) switch is a purpose built double pole, double throw (DPDT) switch, internally wired in manufacture to reverse the connections between the input and output and having only four external terminals. This switch has two pairs of "traveler" terminals that it connects either straight through, or crossed over (transposed, or swapped).

Above text From Wikipedia.


It is a modified dpdt that performs a "cross" function. This swaps the traveler power wire and allows multiple control locations.

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So I guess everyone is right, the two switches are not the same switch. A 4-way switch is a modified DPDT, it is not a normal DPDT. Even though you can take a normal DPDT and get it to perform as a 4-way by adding external jumpers, I don't see a 4-way switch being able to perform every function a normal DPDT can do. If I went to my supply house and asked for a DPDT switch and a 4-way switch, they would give me 2 different switches.

 

[JeepJohn62]

The neutrals do run through the switches, the hot and neutral at the load, reverse every time a switch is toggled

Ok. Hmmmm. But why do it this way? And no safety ground?

I would fix it properly. But it's not mine.

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[Terry D]

Ok. Hmmmm. But why do it this way? And no safety ground?

I would fix it properly. But it's not mine.

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I agree,I never meant it was right, I think it is one of the most craziest electrical things that I have ever seen. To me, there is a code violation there. The outer shell of a lamp screw socket is supposed to have the grounded conductor attached to it to avoid risk of shock. In this case, it could have the ungrounded or grounded conductor going to it depending on the position of the 3-ways. Has anyone ever said, is this in the US or somewhere else?

 

[Bert_]

Ok. Hmmmm. But why do it this way? And no safety ground?

I would fix it properly. But it's not mine.

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It can save wire. Used to see it all the time with the old incandescent yard lights. Would have a switch in the house and one on the pole or other building. Instead of having to run travelers it only took one wire.

Probably hasn't been a code compliant method for 50 years

 

[Alchymist]

I agree,I never meant it was right, I think it is one of the most craziest electrical things that I have ever seen. To me, there is a code violation there. The outer shell of a lamp screw socket is supposed to have the grounded conductor attached to it to avoid risk of shock. In this case, it could have the ungrounded or grounded conductor going to it depending on the position of the 3-ways. Has anyone ever said, is this in the US or somewhere else?

Posted about this in 2014..... yes, it happens in the US.

https://www.garagejournal.com/forum/showpost.php?p=4463155&postcount=26

 

[AntonLargiader]

Has anyone ever said, is this in the US or somewhere else?

The O.P. has historically posted from Mexico.

http://mxelectric.org/three-way-switch-circuits-in-mexico/

 

[Cheeky81]

Hi Guys,

I've been away for couple of days...

Yes, the country in question is Mexico.

Conduits are there ... flexible plastic... not metal.

Now this was an eye opener...
http://mxelectric.org/three-way-swit...its-in-mexico/

I will probably do it properly, I just didn't have the time to do it yet.

 

[jayrush13]

It's a variation of what electricians call a California 3-way has not been legal since the 1920's but still gets used if the wrong wire is pulled. As stated in some other posts it switches the neutral which is a code violation per the NEC and will make the shell of the lamp socket hot sometimes which is also a code violation.

 

[dogdog]

It's a variation of what electricians call a California 3-way has not been legal since the 1920's but still gets used if the wrong wire is pulled. As stated in some other posts it switches the neutral which is a code violation per the NEC and will make the shell of the lamp socket hot sometimes which is also a code violation.

NEC is US code or Canadian Code ? Either case.

He say Mexico... not sure what they follow MEC ?

 

[wyliesdiesels]

NEC is US

CEC is canada

 

[1Garageman]

After seeing this, I would be checking every electrical component in your house!!

 

[MikeF2316]

This is common way to wire up the "AMP" light in automobiles. One wire is connected so it's got power (+12V) when the ignition is on. The other is connected to an alternator output, so there's power (+12V) when the alternator is generating power. With both wires at +12V, the light does not light. When the alternator is not turning, this wire is very close to ground potential due to the low resistance of the alternator wiring, turning on the light.

Of course having full potential at a bulb's terminals is very different when comparing 12 and 120 Volts!

 

[frankush]

Commonly referred to as a barnyard three way circuit in my neck of the woods. Not very common. I've run into a few in 40 years. Rip it out and do it right.

 

[malibu101]

I have seen this type of circuit used in knob & tube wiring in old houses.
Since a hot and neutral were normally run from one end of the house to the other, this just required 1 wire between each switch (as was said by others).

Sure makes for some head scratching when troubleshooting.
Just like with K&T they often switched the neutral. Turn the switch off to work on the light but 120V is still present.