How to a two way switch wiring
Two Way Switching Explained - How to wire 2 way light switch
0:00 / 0:00
Timecodes:
Hey there guys, Paul here
from TheEngineeringMindset.com.
In this video we're going to be looking at
how to control a light fitting with two switches.
This is very useful, for example,
when placing a light switch at the top and bottom
of a set of stairs, or at different doors in a room.
We're going to look at two common ways to do this,
as well as some different variations on the second version.
Now, the colour of the cables varies around the world,
according to different standards.
I'm going to be using the European colour code
for this video, but you should check your local regulations.
I just want to remind you
that working with electricity is dangerous.
We're covering just the theory in this video,
so please do not undertake any electrical work
unless you are qualified and competent.
So, to control a light with two switches,
we of course need two switches,
which have three terminals on the back.
I'll leave some links in the video description down below,
for where to buy these switches online very cheaply.
The name for these type of switches is different
depending on where in the world you are.
The US/North America call these three-way switches.
But the EU calls these two-way switches.
The switch can only be flipped one of two ways,
either up or down.
But if we look at the back of the switch,
then we'll see there are three terminals,
and that means there's four ways
for electricity to flow through the switch.
These will all depend on how the switch is wired.
One terminal is called the common,
and then we have a terminal called line one,
and another terminal called line two.
Let's say we want to control this light fitting
using two switches.
I'll flip them over so you can see how this would work.
I'll also just rotate these to make the drawing
a little easier to understand.
So we have the electricity coming in
from the consumer unit and feeding the light fitting.
We therefore take the live wire
and divert this into the common terminal of switch one.
We run another wire from the common terminal of switch two,
and connect this to the lamp.
We now need to connect the two switches.
So we connect terminal L1 of switch one
with terminal L2 of switch two.
We need to place a brown sleeve at each end of this wire
to warn that it is intermittently live.
We then run another wire from terminal L2 of switch one,
and connect this to terminal L1 of switch two.
Again, placing a brown sleeve
to indicate that this can be live.
At the moment, the electricity can
make it through switch one and into switch two,
but the circuit is broken at switch two.
If we then flip the switch, the circuit is complete
so electricity runs through the entire circuit,
and the lamp lights up.
If we then flip switch one, the circuit is broken again,
so the lamp turns off.
But electricity still flows to switch two
where the circuit is broken.
We could flip switch one again to complete the circuit
or we can flip switch two, and the circuit is also complete.
So we can therefore flip either switch one or switch two
to make or break the circuit,
and thus control the light fitting with two switches.
The second common way to control a light with two switches,
is to convert a one-way switch into a two-way.
Again, we need two switches, and you need to check the back
to ensure that they have three terminals on each.
If your one-way switch only has two terminals,
then you need to replace this.
So we cut the live wire feeding the lamp,
and run this into terminal L1 of switch one.
We then run a grey wire from terminal L1 of switch one
to terminal L2 of switch two.
We need to place a brown sleeve at either end,
to warn that this is intermittently live.
We run a brown wire between the two common terminals
of both switches.
Then we run a black wire from terminal L2 of switch one
to terminal L1 of switch two.
Again, we need to place a brown sleeve at each end
to warn that this is intermittently live.
Lastly, to complete the circuit, we connect terminal L2
back to the supply of the light fitting.
Again, using a brown sleeve to warn
that it's intermittently live.
The electricity can now flow,
and it will pass through switch one
and into switch two where the circuit is broken.
If we flip switch two, we complete the circuit
so the electricity can flow through the common
and out into the lamp.
If we flip switch one,
we break the circuit to the light fitting
so the lamp turns off.
If we then flip switch two, we make the circuit again,
and electricity will flow to the light fitting.
So the alternative ways work almost identically
to the conversion we just saw.
But in this method, we run the live to L2 of switch one.
Then we run a brown cable from L2 of switch one
over to L1 of switch two.
Then we run the grey wire from L2 of switch two
over to L1 of switch one.
We need to place a brown sleeve at each end
to warn that this is intermittently live.
Then we run a black wire between both commons
of both switches.
Again, we need to place a brown sleeve at each end.
Finally, we connect the blue wire from L1 of switch one
back to the light fitting.
Again, placing a brown sleeve at each end.
So to start with, the circuit is broken,
so electricity passes through switch one
and into switch two, but it reaches a dead end.
If we then flip switch one, we complete the circuit,
and electricity can flow through switch one
and into switch two, then back to switch one,
and up into the lamp.
If we flip switch two, we break the circuit,
electricity just flows between the two switches,
and doesn't reach the light.
If we flip switch one, the electricity will flow to
switch one and over into switch two,
across the switch, and back over to switch one
where it can flow to the light fitting.
On the third variation, I won't animate the lines
being connected for this one, as you get the idea,
but we connect the live to L1 of switch one.
Then we run a brown wire between L1 of switch one
to L1 of switch two.
And we run a grey wire between L2 of switch two,
and L2 of switch one.
Then we run the black wire between the two commons.
And finally, we connect the blue wire
between L2 of switch one, and then the lamp.
Remember to add a brown sleeve at all the cables
to warn that they are intermittently live.
The fourth variation is very similar to the last one,
except that the black wire is connected
between the two L1's of both switches,
and the brown wire is connected across the two commons.
Again, remembering to place a brown sleeve on the wires
to indicate that they intermittently live.
Okay guys, that's it for this video.
But to continue your learning,
just click on one of the videos on the screen now,
and I'll catch you there for the next lesson.
Don't forget to follow us on Facebook,
Twitter, Instagram, and of course,
check out TheEngineeringMindset.com
Related queries:
how to install two way switch wiring
how to do two way switch wiring
how is a two way switch wiring
how to 2 way switch wiring
how to wire a two way switch diagram
how to make a two way switch connection
how to two way light switch wiring
how to two way switch connection
how does a two way switch circuit work
how to wire a 2 way switch diagram
