WHILE EXTREME CARE HAS BEEN IMPLEMENTED IN THE
PREPARATION OF THIS SELF-HELP DOCUMENT, THE AUTHOR AND/OR PROVIDERS
OF THIS DOCUMENT ASSUMES NO RESPONSIBILITY FOR ERRORS OR OMISSIONS,
NOR IS ANY LIABILITY ASSUMED FROM THE USE OF THE INFORMATION,
CONTAINED IN THIS DOCUMENT, BY THE AUTHOR and / OR PROVIDER.
You will need...
1. A 3 wire cable that is routed between switch box 1 and switch box
2 - these wire cables comes with a black / red / white wire plus the
bare equipment grounding wire.
2. A 3 wire cable that is routed between switch box 2 and switch box
3 - these wire cables comes with a black / red / white wire plus the
bare equipment grounding wire.
3. A 2 wire cable that is routed between switch box 1 and the
fixture box - this wire cable comes with a black / white wire plus
the bare equipment grounding wire.
4. A circuit power supply source wire cable that is routed to
fixture.
5. Insulated wire nuts to connect / join wire together, variety of
sizes out there so make sure you obtain the correct size.
6. Wire staples, to affix the wire cables to wall studs as needed.
Wire cable must be secured within 6 inches of entering the
electrical box.
7. Wire cable / wire strippers.
8. Screwdrivers as required.
Holes drilled to feed wires through studs must be 1 1/4" from edge
of stud, in instances where the wire cable is closer then the edge
of stud must have a 1/16-in. thick protective metal plate over the
area where the cable is being feed through (may want to notch the
stud so that that the protective plate does not create a bump on the
drywall). Also read the article called '
Wire
Routing Basics'
Wire cables entering the electrical box - secure the cable clamp at
the box snug enough that the cable cannot come out but not too tight
as to pinch the cable and break through the insulated cover of the
cable.
You must have at least 6 inch length of wire inside the electrical
box, it can be a bit more but not less, it can fail an inspection if
the length of each wire is less than 6 inches. Also read the article
called '
Box
Fill Calculations' as there is a limit on how many
wires are allowed for a certain size electrical box.
STEP 1 - Make
certain that the power supply cable is dead - turn off the
electrical breaker at the service panel. Make certain that everyone
in the house is aware of what you are doing so that they do not get
the notion to reset the breaker when another light in the home is
not working.
STEP 2 - Make the
box openings (if a existing home)
STEP 3 - Feed /
Route the wire cables.
STEP 4 -Mount /
Install the Electrical Boxes (make sure the electrical boxes are
secured as some fixtures are heavy and may require additional
support) [The electrical box should not extend beyond the edge of
the finished wall or ceiling so that the fixture can mount flush to
the ceiling and the wall switch cover will mount flush - but it also
should not be recessed too far into the wall or ceiling]; then feed
the wire cables into the electrical boxes. Sometimes because of
tight openings in existing homes, the wire cable may to be feed into
the electrical box then the box put in position and secured.
STEP 5 - Connect
the wires...
Connections Instructions:
(as depicted in the diagrams above)
At the Fixture box...
Two cables entering this box, one is the circuit power supply cable,
the other cable (wire cable # 1) coming from switch 1.
* a) using an insulated wire nut connect / join the black wire from
'circuit power supply cable' + the white wire of the cable coming
from switch 1.
* b) connect the white wire from 'circuit power supply cable' to the
grounded conductor (neutral) of the fixture - if the fixture has
screw type connections then connect to the silver color screw.
* c) connect the black wire coming from switch 1 to the switched
ungrounded conductor (hot) of the fixture itself - if the fixture
has screw type connections then connect to the brass color screw.
* d) please see under important notes in regards to the equipment
grounding conductor (bare wire).
At switch 1 box...
Two cables entering this box, one is coming from the fixture (wire
cable # 1), the other cable coming from switch 2 (wire cable # 2).
* a) using an insulated wire nut connect / join the white wire
coming from fixture + the black wire of cable coming from switch 2.
* b) connect the black wire coming from fixture to the common screw
of switch 1.
* c) connect the white wire coming from switch 2 to one of the
remaining main screws of switch 1.
* d) connect the red wire coming from switch 2 to the last remaining
main screw of switch 1.
* e) please see under important notes in regards to the equipment
grounding conductor (bare wire).
At switch 2 box...
Two cables entering this box, one cable coming from switch1 (wire
cable # 2) and one cable coming from switch 3 (wire cable # 3).
* a) using an insulated wire nut connect / join the black wire
coming from switch 1 + the black wire coming from switch 3.
* b) connect the white wire coming from switch 1 to one screw that
is a matching pair. (both the red and white wires coming from switch
1 must go to a matching pair of screws at switch 2)
* c) connect the red wire coming from switch 1 to the 2nd screw that
is a matching pair. (both the red and white wires coming from switch
1 must go to a matching pair of screws at switch 2)
*d) connect the white wire coming from switch 3 to one screw from a
different matching pair of screws. (both the red and white wires
coming from switch 3 must go to a matching pair of screws at switch
2)
*e) connect the red wire coming from switch 3 to the 2nd screw that
is a matching pair. (both the red and white wires coming from switch
3 must go to a matching pair of screws at switch 2)
***Just to clarify further - The red
and white wires coming from switch 1 go to one set of matching
screws at switch 2 -- The red and white wires coming from switch 3
go to a different set of matching screws at switch 2 - A matching
set is 2 screws of the same color***
* f) please see under important notes in regards to the equipment
grounding conductor (bare wire).
At switch 3 box...
One cables entering this box coming from switch 2.
* a) connect the black wire coming from switch 2 to the common screw
of switch 3.
* b) connect the white wire coming from switch 2 to one of the
remaining main screws of switch 3.
* c) connect the red wire coming from switch 2 to the last remaining
main screws of switch 3.
* d) please see under important notes in regards to the equipment
grounding conductor (bare wire).
Important Notes:
By electrical codes you MUST have at least 6 inches of wire in the
electrical box itself, and also the wire must be able to reach at
least 3 inches outside the box, it can fail an electrical inspection
if the required min. wire length is not met. You may have the wires
a bit longer (within reason) but they cannot be shorter. Also see
the note on box fill further down in this article.
You are allowed to re-designate a white wire to be used as a hot
(ungrounded conductor) in switch circuits but in those cases where a
white wire is used in this manner, you must wrap a piece of black
electrical tape around that white wire inside the box to signify
that is being used as an ungrounded (hot) conductor.
You cannot re-designate a white wire that is actually connected to
the light fixture itself. At the fixture itself, the white wire must
be the grounded conductor (neutral) coming from the circuit power
supply cable.
In the 4 way configuration depicted on this page, the white wire on
both ends of wire cable # 1, wire cable # 2, and wire cable # 3 have
been used to carry a switched ungrounded conductor (hot) part of the
circuit and therefore as stated should have a piece of black
electrical tape wrapped around the wire in the box. The white wire
from the power supply cable that goes to the fixture itself at the
fixture box location is a grounded conductor (neutral) and therefore
is left as white with NO black tape on it.
If the fixture has screw type connectors, the switched ungrounded
conductor (hot) is connected to the brass color screw, and the
grounded conductor (neutral) is connected to the silver color screw.
If it has black and white wires coming from fixture, then just
connect black to black and white to white. Use wire nuts of the
correct size to join wires together.
The wire cable running between switch 1 and switch 2 (wire cable #
2) and between switch 2 and 3 (wire cable # 3) has 3 wires in it -
black / red / white (plus the bare equipment grounding wire).
What is not shown in the drawings to avoid confusion, is that each
wire cable also has a bare equipment grounding wire included. This
wire is connected to an equipment grounding screw in each electrical
box (if the box is metal), joined either through the equipment
grounding screws in the box itself or via a wire nut to the bare
wire of the next cable entering / exiting the box, it is also
connected to any equipment grounding screw (if there is one) on the
switch itself, as well as any equipment grounding screw at the
fixture (green wires that attach to the fixture are grounds). Now if
using a plastic box, it is made of a material that is non
conductive, however some plastic boxes have a metal strip inside
that can still be used to connect equipment grounding wires, in the
event that it does not use wire nuts to join the bare equipment
grounding wires together. The equipment grounding wire (bare in most
cables) must be electrical conductively joined throughout the
circuit. Green wires are also equipment grounding conductors.
At the 3 way switches (switch 1 & 3) there are 3 main electrical
screws, one of these 3 screws is distinctly different in color
(perhaps darker) than the other 2. This screw connection is called
the common screw. It is very important that in order for all the
switches to work as they are intended to that the correct wire is
attached to the common screw. Basically as depicted in the drawings
one switch has the ungrounded conductor (hot) from the circuit power
supply cable attached to the common screw, where the other switch
has attached on the common screw the switched ungrounded conductor
(hot) feed to the light fixture itself.
Please also note that there are a variety of manufactures out there
that make 3 way switches so it is possible that the switch you buy
may have the common screw located in a different spot or side of the
switch then depicted in the drawings in this article, just make sure
that the wire depicted to go to the common screw of each of the
switches is actually connected to the common screw of the 3 way
switch you bought. The other 2 wires going connected to the
remaining main screws of the 3 way switch does not matter as long as
one wire of the 2 remaining wires go on each of the remaining 2
screws.
At the 4 way switch (switch # 2) there are 2 sets of matching
screws, one set will match in color and the other set will be
distinctly different perhaps darker in color, it is important that
the traveler wires (red and white in the design in this article)
from the previous switch are connected to one matching set, and the
traveler wires going to the next switch (red and white in the design
in this article) are connected to a different matching set.
If there is an equipment grounding screw on the 3 way or 4 way
switch it may be green in color and be separated away from the main
connections of the switch and likely part of the metal frame that is
also part of the mounting structure of the switch.
Extensions to this Switch
circuit...
Be Aware that there is a limit by code on how many wires can be in a
given size electrical box, when adding more wires to the same box
you may have to install a larger and / or deeper box to allow space
for more wires coming and out of the box.
Here is an article / explanation in regards to box fill calculations
'
Box
Fill Calculation'
The instructions here are based on the fact that the circuit has
already been wired to the configuration shown in this article and we
are now making the wiring changes for onward power.
From the switch locations....
No onward connections are possible from any switch locations because
a grounded conductor (neutral) does not exist with this
configuration at these locations.
From the fixture location...
Onward 'always on circuit power' and 'switched power' is possible
from the fixture location.
Option 1: Onward
Always On Circuit Power...
(showing bellow the fixture portion of the circuit)
Not shown in the diagram but the onward cable
also has a bare wire (equipment grounding conductor) that also must
be connected to all the other bare wires at the fixture electrical
box.
Connection Instructions for
onward cable (always on state)
* a) Using an insulated wire nut, connect / join - the black wire
from 'circuit power supply cable' + the white wire coming from
switch 1 (wire cable # 1) + the black wire of onward cable.
* b) Using an insulated wire nut, connect / join - the white wire
from 'circuit power supply cable' + the white wire connecting to the
grounded conductor (neutral) of fixture (shown as white in diagram)
+ the white wire of onward cable.
Identification of wires in onward
cable....
Black - Ungrounded conductor (hot - always on)
White - Grounded conductor (neutral)
***************
Option 2: Onward
switched power...
(example more than one light fixture controlled by the same 3 & 4
way switches)
(showing bellow the fixture portion of the circuit)
Not shown in the diagram but the onward
cable also has a bare wire (equipment grounding conductor) that
also must be connected to all the other bare wires at the
fixture electrical box.
Connection Instructions for
onward cable (always on and switched)
* a) Using an insulated wire nut, connect / join - the black
wire coming from switch 1 (wire cable # 1) + the black wire
connecting to the switched ungrounded conductor (hot) of fixture
(shown as black in diagram) + the black wire of onward cable.
* b) Using an insulated wire nut, connect / join - the white
wire from 'circuit power supply cable' + the white wire
connecting to the grounded conductor (neutral) of fixture (shown
as white in diagram) + the white wire of onward cable.
* c) Using an insulated wire nut, connect / join - the black
wire from 'circuit power supply cable' + the white wire coming
from switch 1 (wire cable # 1) + the red wire of onward cable.
Identification of wires in
onward cable....
Black -Switched ungrounded conductor (hot - switched)
Red - Ungrounded conductor (hot - always on)
White - Grounded conductor (neutral)
Foreign Users:
The colors of the wires depicted
are based on the standards and code requirements / configuration
in the United States and Canada. If you are viewing this site
from a foreign country, your wiring standards and color of wires
may be different but the principal and sequence of wiring will
still remain the same. Therefore the information in this article
may still be of use to you regardless of what country you may be
in. Just translate the colors used here to the color of wires
used in your country in regards to ungrounded (hot) conductors /
grounded conductors (neutral) and equipment grounding conductors
as well know applicable code requirements in your country.
