So
I posted something about how I had read that the average hobby
woodworker with no dust control breaths in more toxic dust in a day
that a professional woodworker with the full dust control mechanisms
breaths in a year. With that, I made have made a stand for my cyclone filter and Shop-Vac. I am now working on building a home
made a dust filter, for which there are many pictures on the internet
and mine will be up shortly (I hope).
In
building the dust filter, I managed to get a scroll cage furnace fan
from a local AC company. The fan had four power wires to control the
four speeds (High, Medium-High, Medium-Low, & Low). So off I
went to supply catalogs and I was shocked at the price of a 4-way
selector switch. I thought about it, and then came up with a cheaper
plan.
This
blog describes how to build 4-way selector switches by using several
3-way light switches from your local hardware store. So rather than
several hundred dollars for the selector switch, I wired one up for
about $6, not including other parts I had or scrounged for free.
This switch could easily be extended into other types of switches for
other types of fans or more complex items.
Disclaimer:
Electricity is inherently dangerous and misuse can result in a fire,
shock, injury, or death. You should never work on live electricity
and therefore either unplugging the item or turn off the appropriate
circuit breaker. Always double check to see that no electricity is
running with a working voltage detector. If you are not comfortable
wiring up simple electrical outlets, this information is not for you
and you should stop to hire a professional. It is up to the
individual to determine whether he/she is capable and competent to do
the work following the information provided here. Always follow the
electric code requirements specific to your area and before
undertaking any electrical project, contact your local electrical
authority and your insurance company to ensure that you comply with
all policies, warranties, regulations and authorities concerning this
work. Make sure all wiring is properly grounded. By reading further, you agree to hold this blog and its owner
harmless for any property damage, personal injury and/or death, or
any other loss or damage that may result from your use of the
information provided. Ultimately you are responsible for your safety
and you assume all risks from the application of any of this
information.
So
before going further to the diagrams and descriptions, make sure you
know the basics of electricity, how to be safe with it, and how to
wire up a basic electrical outlet circuit. If you can’t do a basic
electrical circuit, you won’t be able to do this.
Let’s
look at a standard 3-way light switch, like those on opposite ends of
a hall controlling a light. The diagram below shows the internal
wiring with the toggle switch up and down. Switching the toggle
switch then changes which traveler is connected to the common.
Now
if you can bring the power into the common and connect the traveler
lines on two switches, you can now wire a 3-way switch. Below is the
simplest way to wire up a 3-way switch. There are many other ways to
properly wire up a 3-way switch; however, if you don’t understand
this simplest method, you won’t understand the more complex 3-way
wiring diagrams. In the case below, the power is coming in the first
switch on the common screw. Depending on the direction of the first
toggle switch, the power is then either going down the black or red
traveler wire within the wire set. If the second switch matches the
same orientation as the first, the power can then go to the light to
turn it on and return via the neutral line. If either switch is
changed, the circuit is open and the light goes out.
Now
that you understand a basic 3-way switch, let’s think of it
differently. To do this, I have drawn the same switches upside down,
as in the diagram below. In this case, you can now bring the power
in and then have the toggle switch be a selector switch. In one
position, you are sending power to line A and in the other position,
you are sending power to Line B. If you start to try this, for sure,
get a meter and check the continuity. You will see it works like the
diagram below.
From
here, one can see that you can put use the basic 3-way switch to send
power in one of two directions. If you put a second 3-way switch
next to the first one, you are now having more options on where to
put power. The first switch would send power to Line A or the second
switch. From the second switch, you could then send power to either
a Line B or Line C. One thing to also point out is if you are
sending power to Line A, the second switch does not get any power, so
it can be in any position.
Put
a third 3-way switch in line, and you now have a 4-way selector
switch. This is then what I did for my fan. In my blower motor, the
power colors corresponded to High (Black), Medium-High (Blue),
Medium-Low (Yellow), and Low (Red). In addition, the white was the
neutral, green was the ground, and brown was for the capacitor. In
trying to determine what color was what, I did some internet
searching and found that different fans can have different wiring and eventually spent time looking at the small wiring diagram.
Be smart, look at the wiring diagram for your fan to be certain.
Also, once wired, use your electric meter to confirm everything is
correct.
Below
is then the wiring diagram and switch settings for my motor and the
4-way selector switch. My wiring diagram works great. In addition
to the 3-way switches, I put a 60-minute bathroom timer in front of
it. This will allow me to run the fan on low when I am working and
creating dust. When I leave, I can turn it on high and let it run
for 60 minutes to cut down on the dust.
A
picture of the final switches is shown below before screwing in the
3-gang box. The wires from the fan were not very long and had to be
lengthened to run to the switches. The lines were extended with white
wire and then color coded with electrical tape. Out of habit I wrap
all of my wire nuts as there could be vibration and wrap the switches
(although one was not before the picture was taken). The holes going
through the wood are not grommet protect and do not need to be as the
holes in the wood are much smaller than the holes in the metal.
Hope this was of interest to someone out there,
G
