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 switch
box 2.
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...
One cable entering this box, (wire cable # 1) coming from switch 1.
* a) connect the black wire coming from switch 1 to the switched
ungrounded conductor (hot) of fixture (shown as black in picture) - if
the fixture has screw type connections then connect to brass color
screw.
* b) connect the white wire coming from switch 1 to the grounded
conductor (neutral) of fixture (shown as white in picture) - if the
fixture has screw type connections then connect to the silver color
screw.
* c) please see under important notes in regards to the equipment
grounding conductor (bare wire).
At switch 1 box...
Two cables entering this box, one coming from switch 2, and one coming
from the fixture
* a) connect the black wire coming from fixture to common screw of
switch 1.
* b) using an insulated wire nut connect / join the white wire coming
from fixture + the white wire coming from switch 2.
* c) connect the red wire coming from switch 2 to the one of the
remaining main screws of switch 1.
* d) connect the black 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...
Three cables entering this box, one cable coming from switch 1 (wire
cable # 2) and one cable coming from switch 3 (wire cable # 3), and one
cable being the 'power supply cable'.
* a) using an insulated wire nut connect / join the white wire coming
from switch 1 + the white wire from 'circuit power supply cable'.
* b) using an insulated wire nut connect / join the black wire coming
from switch 3 + the black wire coming from 'circuit power supply cable'.
* c) connect the red wire coming from switch 1 to the one screw that is
a matching pair of screws on switch 2 (both the red and black wires
coming from switch 1 must go to a matching pair of screws at switch 2)
* d) connect the black wire coming from switch 1 to the 2nd screw that
is a matching pair of screws on switch 2 (both the red and black wires
coming from switch 1 must go to a matching pair of screws at switch 2)
*e) connect the red 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)
*f) connect the white 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
black 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.***
* g) please see under important notes in regards to the equipment
grounding conductor (bare wire).
At switch 3 box...
One cable entering this box coming from switch 2 (wire cable # 3).
* a) connect the black wire coming from switch 2 to the common screw of
switch 3.
* b) connect the red wire coming from switch 2 to one of the remaining
main screws of switch 3.
* c) connect the white wire coming from switch 2 to the last remaining
main screw 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 # 3, going between switch 2 and 3 has 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. All other white wires in this configuration
are grounded conductors (neutrals) and therefore NO black tape on them.
If the fixture has screw type connectors, the 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 a grounding screw in each electrical box (if the box is
metal), joined either through the 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 grounding screw (if there is one) on
the switch itself, as well as any 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 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 had the 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 between the remaining screws of one switch to the other
switch does not matter as long as one wire of the 2 remaining wires go
on each of the remaining 2 screws of the screw.
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 from the previous switch are connected to one matching set, and
the traveler wires going to the next switch are connected to a different
matching set.
If there is an equipment grounding screw on the 3 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 fixture location...
Only switched onward power is available from the fixture location.
Onward switched power...
(example more than one light fixture controlled by the same 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 switch electrical box.
Connection Instructions
for onward cable (switched)
* a) Using an insulated wire nut, connect / join - the black
wire from fixture + the black wire connected to common screw
of switch 1 + the black wire of onward cable.
* b) Using an insulated wire nut, connect / join - the white
wire coming from fixture + the white wire coming from switch
2 + the white wire of onward cable.
Identification of wires
in onward cable....
Black - Switched ungrounded conductor (hot - switched)
White - Grounded conductor (neutral)
*************
Switch 2 Options:
Only 'always on' power is available from the switch 2
location
Onward always on power...
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 switch electrical
box.
Connection
Instructions for onward cable (always on)
* a) Using an insulated wire nut, connect / join -
the black wire from 'circuit power supply cable' +
the black wire of onward cable + the black wire
coming from switch 3.
* b) Using an insulated wire nut, connect / join -
the white wire coming from 'circuit power supply
cable' + the white wire of onward cable + the white
wire coming from switch 1
Identification of
wires in onward cable....
Black - 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.
