Hot 3 way switch - Electrician Talk - Professional Electrical Contractors Forum

subelect · 07-11-2008, 11:21 PM

A co-worker came back from a service call at an old farm and told me about what he encountered.
He has been in the electrical field for over 50 years. He asked me if I had ever heard of a "hot 3 way" switch, which I never had.
He told me that it was an old way of wiring that is in violation of present codes, but it was common back in the 50s when he wired this farm for the first time. They wanted a 3 way loop for an luminaire and to power up an outlet at the other 3 way with the same wires.

The (14/2) hot and neutral wires are brought into the first 3 way switch; both are pigtailed to the (14/3) travelers and to the 3 way. The remaining
wire on the 14/3 is connected to the common on the first switch.

At the other 3 way switch, the travelers are now hot & neutral and can be pigtailed to power up an outlet. They are also attached to the second 3 way switch, with the luminaire's switch leg being on the common terminal of the 3 way.
The common wire from the first 3 way is spliced inside the second 3 way switch box to the return from the luminaire.

He told me that it worked great back in the day and it saved the customer the added expense of extra copper wire. He said that when it was common to take several monthly payments on a bill of $10, you did anything that you legally could to keep the bill down.

He told me about it only as a warning to watch out for that on some of the older buildings still in use. I did not get much chance to ask him any more about it.

I know that it is a dumb question because it is illegal to do this, but I like to know exactly what the violations are with this arrangement. Besides switching the neutral without breaking the ungrounded conductors, is there another violation?

Thanks.

Lz_69 · 07-12-2008, 04:26 AM

Quote:

Originally Posted by subelect

A co-worker came back from a service call at an old farm and told me about what he encountered.
He has been in the electrical field for over 50 years. He asked me if I had ever heard of a "hot 3 way" switch, which I never had.
He told me that it was an old way of wiring that is in violation of present codes, but it was common back in the 50s when he wired this farm for the first time. They wanted a 3 way loop for an luminaire and to power up an outlet at the other 3 way with the same wires.

The (14/2) hot and neutral wires are brought into the first 3 way switch; both are pigtailed to the (14/3) travelers and to the 3 way. The remaining
wire on the 14/3 is connected to the common on the first switch.

At the other 3 way switch, the travelers are now hot & neutral and can be pigtailed to power up an outlet. They are also attached to the second 3 way switch, with the luminaire's switch leg being on the common terminal of the 3 way.
The common wire from the first 3 way is spliced inside the second 3 way switch box to the return from the luminaire.

He told me that it worked great back in the day and it saved the customer the added expense of extra copper wire. He said that when it was common to take several monthly payments on a bill of $10, you did anything that you legally could to keep the bill down.

He told me about it only as a warning to watch out for that on some of the older buildings still in use. I did not get much chance to ask him any more about it.

I know that it is a dumb question because it is illegal to do this, but I like to know exactly what the violations are with this arrangement. Besides switching the neutral without breaking the ungrounded conductors, is there another violation?

Thanks.

It's called Cater switching and here's a link to and old thread on it.

Three way switching standard, coast, carter

JohnJ0906 · 07-12-2008, 08:53 AM

randomkiller · 07-12-2008, 09:47 AM

I'm just glad I don't do resi.

waco · 07-12-2008, 06:11 PM

I've never understood the objection to "switching the neutral," but as far as I can tell, I guess what you describe fits that setup. When you bring all three conductors through the light, you mark the "hot" leg with black tape and leave the other wire white for neutral (because it ties to neutral in the "feed side" switchbox,) but I guess that is "switching the neutral."

We used to use three-ways to do exactly what you describe -- supply power downstream, but you don't see it much anymore

Seems to me, if the black or red is used to feed the light, then it isn't really switching the neutral.

brian john · 07-12-2008, 06:17 PM

Hot set of 3-ways
Lazy Suzy
Electrician nightmare.

just a few of the terms I have heard for this.

subelect · 07-13-2008, 08:14 AM

Thanks for the info.
Rick

Rong · 07-13-2008, 08:36 AM

Quote:

Originally Posted by randomkiller

I'm just glad I don't do resi.

You and me both! I have done my fair share of it over the years and hopefully will not have to do it again. After all anybody can do it cuz the Home Depot guy ''splained it to em".

JohnJ0906 · 07-13-2008, 09:09 AM

Quote:

Originally Posted by waco

I've never understood the objection to "switching the neutral,"

Because there is still voltage at the light from "hot" to the EGC.

waco · 07-13-2008, 10:47 AM

I guess I don't understand the method the terminology "switching the neutral" refers to. I have run three-conductor through the light, using the black and red as travelers and the white as the switched leg. One side goes to the neutral at the box feeding the circuit and the other side goes to the common of the other three-way switch, which gets taped to show it is "hot." But it isn't always hot.

JohnJ0906 · 07-13-2008, 10:55 AM

So you are using the white conductor. That is not switching the neutral.

When I hear "neutral", I think "grounded conductor"

waco · 07-13-2008, 11:35 AM

Then, if a light switch breaks the grounded conductor, then that is "switching the neutral?" Of course it is.

worn kleins · 07-17-2008, 08:57 PM

Always remember "Nuetral is always white but white isn't always nuetral." It could save your life. Another term for this set up, "Okie 3 way"

nolabama · 07-17-2008, 09:07 PM

i have seen the grounding conductor used as a grounded conductor in three way switches around here - allows the neutral to be sent on the 14/2 with the travelers- sucks got the

knocked out of me in that box

Rong · 07-17-2008, 09:08 PM

Quote:

Originally Posted by worn kleins

Always remember "Nuetral is always white but white isn't always nuetral." It could save your life. Another term for this set up, "Okie 3 way"

good point!

480sparky · 07-17-2008, 09:12 PM

Quote:

Originally Posted by worn kleins

Always remember "Nuetral is always white but white isn't always nuetral." It could save your life. Another term for this set up, "Okie 3 way"

Never working on K&T then? Everything is black!

BackInTheHabit · 07-17-2008, 09:50 PM

I'd call it OLD SCHOOL wiring.

jrclen · 07-18-2008, 12:42 PM

Quote:

Originally Posted by BackInTheHabit

I'd call it OLD SCHOOL wiring.

That is exactly what it is.

Some day someone will be on here all amazed that they found a three wire feeder to a sub panel in a garage or barn. And everyone will be talking about what a hack the guy was who put that in.

Slider · 07-19-2008, 09:16 PM

I had a service call a couple months ago at an old church for the "hot 3way deal"
It took me a while but I figured it out. Drove me crazy for a little while though.

micromind · 07-19-2008, 11:38 PM

If this circuit feeds a screw-shell type lampholder (keyless), it would violate 410.47.

"Where supplied by a circuit having a grounded conductor, the grounded conductor shall be connected to the screw shell.

In this circuit, the screw shell can be connected to the hot or the neutral, depending on the position of the switch that it's connected to.

Rob