More Three-Way and Four-Way Switch Circuits - Which One Should I Use - Part VII
by Phil Kingery
Which One Should I Use, Part VII (Preamble)
Welcome back to HTI. Even though you are reading this in February (most
likely), I am actually writing this at the Las Vegas airport the day after the Winter 1998 CES
convention. I have a few hours before my plane takes me back home so I am sitting on the floor next
to gate #3 typing on my laptop. Bob Hetherington (HTI founder and all ‘round nice guy) sent me an
email before I came to Las Vegas and reminded me that February is just around the corner. So here I
am, sitting on the floor, writing as fast as I can.
First let me tell you about CES which ran January 8-11. As always, it
was huge. Most of it was in the Las Vegas Convention Center, with a major part in the nearby Hilton
(more on that later) plus the Sands plus a few other hotels. (A few years ago, they moved all the
"adult" stuff to one of the hotels. Now I can no longer pretend that I just accidentally
walked by.) All the X-10 guys were there; the regular X-10 booth in the big convention center plus
the "X-10 Pro" guys over in the Hilton. I was able to talk to a few of X-10 Pro guys for
a short time, but kept missing the other X-10 people. The big news, however, at this year’s CES was
not X-10 (its been around for years), it was HDTV and DVD (that’s "High
Definition TV" and "Digital Versatile Disk".).
Now back to the Hilton. Most of the Home Automation stuff was there,
plus the Habitech Institute. I was asked to speak at this year’s CES in the "Habitech"
section. I am pleased to report that we had standing room only. (I can only assume that either I
was worth listening to, or they thought I was somebody else. Either way, once they inside the room,
we wouldn’t let them leave.) If you were among the attendees, please drop me an email at
pkingery@act-solutions.com
and let me know what you thought of CES. (If you also went to the new "Star Trek
Experience" at the Hilton, let me know what you thought of that, too. It was so
cool!! I even had dinner in Quark’s Bar.)
Back in December 1997, we began this two-parter on 3-way circuits. It
is my intention that this second part will finish up 3-ways and throw in a little 4-way
information. Since this is the second of two parts, you will be very confused if you have not read
the first one. Therefore, unless you already have done so, I strongly suggest you go back and read
"
Which One Should I Use, Part VI
". There are obviously five more articles before that and while I think every one of them is
worth your reading, only part 6 has anything to do with 3-ways (Editors Note: You can find all
of Phil's articles in the
HTINews Article Library
). And now, without further adieu, we are ready to proceed into:
Which One Should I Use, Part VII
(More Three-Way and Four-Way Switch Circuits)
You may recall from the last part, that I said that we get a lot of
technical calls on 3-ways (and I don’t mean the kinky kind). It is common to find that the
installer doesn’t understand standard 3-way circuits, let alone X-10
3-way circuits.
Just what "is" a 3-way circuit? Perhaps I assumed too
much when I failed to explain, in the most basic way, what a 3-way circuit is. I taught a class in
Las Vegas and after going over all the main 3-way circuit variations, someone raised their hand and
asked, "When would I ever see a 3-way circuit?". You may have seen them but simply did
not realized what they were.
 Perhaps
it was two light switches at the ends of a long hallway (like figure 1), or at the top and bottom
of a stairway, or even a switch in the kitchen and one in the garage that both control the same
light. A 3-way circuit has the ability of controlling a load from two different locations.
We intuitively know that a light switch that is "down" is
usually "off" and one that is "up" is usually "on". You may have
never noticed, however, that in the special switches made for 3-way circuits do not have the
familiar "on" and "off" embossed into the plastic. That is because
"on" can be up or down, depending on the position of the other switch.
There are many variations in standard 3-way wiring and in the last
part, we went over four of them:
-
Standard 3-way circuit with the load at the end of the run.
-
Standard 3-way circuit with load in the middle of the run.
-
Standard 3-way circuit with the load at the beginning of the
run.
-
Standard 3-way circuit with the load at the beginning of the run,
switches split.
This installment will cover:
-
Standard 3-way with one switch at the beginning of the run and the
second switch and load split.
-
Standard 3-way "coast" circuit.
-
Standard 4-say circuits (just a one example).
(Let me get one more thing off my chest. Just because my drawings
usually start with the breaker panel on the left and then flow to the right, does not mean that
yours will always be in this "left-to-right" pattern. Yours may be left-to-right or
right-to-left, up-to-down or down-to-up. As long as the circuit is wired in this
progression, it is the same. Got that? I had a guy tell me one time that his circuit was
different because his panel was on his right and the light was on his left.)
Here are some other things to consider.
-
In a mechanical 3-way, the current must flow through both
switches.
-
In an X-10 3-way, the current flows only through the
3-way master switch.
-
A standard 3-way circuit can not be converted to an X-10
3-way circuit by replacing only one switch. Sorry, that simply does not work.
-
If a dimmer receiver is designed to work without a neutral connection
(it only needs "line" and "load" wires) then I call it a "2-wire"
dimmer. While it’s true that the
control
lead makes it a total of 3 wires, I still consider it a "2 wire" dimmer
-
If a dimmer receiver is designed with a neutral connection (it needs
"line", "neutral" and "load" wires) then I call it a
"3-wire" dimmer. While it’s true that the
control
lead makes it a total of 4 wires, I still consider it a "3-wire" dimmer
-
All relay receivers require a neutral wire.
-
Also, please note that in many of the diagrams that follow, the wire
colors seems to change color. Believe me, they will not magically change colors as you connect them
to various X-10 units. I simply chose the wire colors to show those most commonly used in standard
3-way wiring scenarios and then I changed them to show the wire colors of the X-10 receivers.
Lets begin this with a 3-way arrangement that is my favorite but
unfortunately it is not as common as most of the others.
 Figure
2 shows a standard 3-way circuit with the switch at the beginning of the circuit and then the
second switch and the load are split. Although this circuit arrangement may appear the most
difficult, it is actually one of the easiest to change to X-10.
Figure 3 shows the best way to install the X-10 receiver and slave switch.
 Because
of the availability of all the needed wiring, any of the X-10 3-way master receivers can be
installed. That means that if you choose to use a 3-wire, 3-way dimmer (one that
requires a neutral connection), you can. If you choose to use a relay receiver (which also requires
a neutral connection), you can do that, too. That is because neutral is available in the junction
box.
If you are sure that you will only need a 2-wire, 3-way dimmer, you can swap the
locations (figure 4) and it should work just as well.
 If
you do, however, you won’t be able to change your mind later and use a 3-wire, 3-way dimmer or a
relay receiver because there is no neutral in that box and no way to get it there. If it were up to
me, I would put the master receiver in the middle box (the first one in the circuit). It just makes
things easier. Like many of the previous examples, converting this type of 3-way to an X-10 3-way
requires no wiring changes in the load j-box.
Figure 5 is just about the strangest 3-way arrangement I have ever seen.
 It
is called a "coast" or "California" 3-way. I’m sure that there is a great story
about how this first came about, but unfortunately, I don’t know it. (If you do, please email me at
pkingery@act-solutions.com
.) Often, this same basic arrangement is wired in such a way as to accommodate two loads, one at
the beginning and one at the end of the run (figure 6).
 Since
line and neutral wires exist in every box, this is one of the easiest ones to convert to an electronic 3-way.
The example (figure 7) shows the installation of the slave switch in place of the
first mechanical 3-way and then a 2-wire dimmer in place of the second one.
 Since
both boxes have the same wiring available, the slave and master is easily swapped. Since neutral
exists in both junction boxes, a 3-wire, 3-way dimmer or a relay receiver can also be used.
Although not as common as 3-ways, a 4-way switched circuit can also be converted
to an X-10 4-way.
 Figure
8 is a typical 4-way circuit diagram. Bear in mind that there are as many variations in how 4-ways
can be wired as was shown in the 3-way circuits (but I am way too lazy to draw all of those
variations). Only one example will be shown here. The diagrams previously shown on 3-ways can be
used as reference should this example not be exactly as is needed.
Figure 9 shows the arrangement of two slave switches and one 3-way master
receiver.
 Since
this example is lucky enough to have a neutral in every box, it is quite flexible in the
arrangement and what receivers can be used. Believe me, your luck runs out rather quickly when the
4-way circuit is wired in one of the many other ways that it can be wired.
BIG NOTE
:
All electrical work should be done by a qualified and licensed electrician
adhering to all national and local electrical codes. Although circuit breakers are not shown,
appropriately sized breakers are required on all circuits. And most importantly, Never use the
ground wire for anything other than ground!
As the sun slowly sets in the west, I see that we have come to the end
of another chapter in this "Which One Should I Use" series (which seems to go on and on
and on and on....). I really hoped that this would not turn into a three parter, but it is clear
that this is pretty long and to go into any troubleshooting would make it unbearable huge. I had
hoped to get into some other variations in 3-ways. Charles Sullivan
(cwsulliv@nr.infi.net
) has taught me something new about residential 3-ways that I did not know (believe me, no
one knows everything about X-10). Perhaps we will discuss it in the next part. The next chapter
(April 1998) we have the option of finishing up 3-ways, looking at some slight, but important
variations plus troubleshooting, OR we can drop this subject and go on to something
new. I will let you decide. Depending on your votes, the next episode will be:
3- & 4-way troubleshooting
Noise and filtering
The basics of the X-10 binary codes
...or suggest your own topic.
You are going to have to let me know what you want, however I will only
take votes until the middle of March. You know what they say in politics: Vote soon and vote often!
Cast your vote through email:
pkingery@act-solutions.com
I hope to see you at the Home Automation Association Convention in
Orlando Florida, February 7-10. I will be teaching two classes (both on Monday, February 9th) at
the convention so please stop by and say "Hey". I will also be teaching a full two-day
course for our representatives. Remember, if you have already attended one of my classes, I need
you to stand at the back and laugh at all my jokes and applaud wildly at the appropriate places.
Well, children, until next time....
Can I use the slave switch any differently than these examples?
Why do some light bulbs just not work with 3-ways?
My new X-10 3-way will come "on" okay, but why can’t I can’t
turn it "off"?
What will become of Captain Coupling?
Will we ever return to finish complex signal coupling?
Stay tuned, children! Same Bat Time, same Bat Channel!
Phillip Kingery is the representative of Advanced Control Technologies,
Inc. and teaches X-10 related classes around the country. Email him at
pkingery@act-solutions.com
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