This video is going to explain how 2 way switching works. In some countries
it's called 3 way switching but in the UK it is called 2 way switching.
That means that you have one light which is represented by this lamp that can be
switched off from two locations. In other countries they do call it 3 way
lighting such as in America etc because the switches used do have 3 ways,
but in the UK this is normally known as 2 way switching. A switch like this
which is 2 way will have a com terminal an L2
terminal and then L1 terminal. This switch does not really have an on and
off position. It's either in the L1 position or the L2 position depending
on where the switch is. I've created a basic circuit and this is exactly the
same as what you'll get in your property. The only difference is that we're using
a battery instead of the power supply which will be a consumer unit we're also
using a low voltage lamp, but the switch is exactly the same as what you would
find in a normal property. This switch has a com, a L2 and a L1 terminal.
Some switches on a 1 way system only have the com and the L1 so it does
depend what kind of switch you've got. If you want a 2 way system you are going
to need two switches that have a com, L1 and the L2.
So this is very simple to explain and I have done some basic schematic diagrams that
should help you to understand this fully. So that is our consumer unit or
our battery we have the positive supply that is going into L1 that then comes
out of the top of the com and goes to the lamp. The negative then goes from
the lamp back to the power supply which in this case is the battery. When you
flick the switch it creates the circuit and the light comes on. This is the basic
drawing that I've done you can see that we have the switch the lamp and the power supply
showing the positive and negative. If we flick the switch the lamp is
energized which makes it illuminate, flip the switch again and then it goes off.
This is exactly the same as what you would have at home if you have
a lighting circuits in a room but the cable used to wire it will be a
lot different. You would use something like that. So inside there you have the
conductors which are insulated and then they are insulated again by this grey
sleeving. This piece is actually a piece of three core and earth this is actually
used for doing a two-way or a 3 way lighting system. You will notice that
this cable has a bare earth wire that would always be sleeved with green and
yellow sleeving in the UK, but for the purpose of this demonstration I'm going
to omit the earth wire. So this is a very basic 1 way lighting arrangement
that allows the lamp to be switched on and off from the one location. You may
want to be able to switch the light on or off from another location so that is
very easy to do you simply get another switch, let's give you a close up of that
you can see it's got the com at the top there the L2 terminal and the L1.
So in order to do 2 way switching you're going to need two of these switches so
I'll just place that on there to make it easier to wire. I'm just going to
disconnect the battery which at home would mean switching off and isolating the
circuit. I'm now going to undo the wire that's in the com terminal and I'm
going to place that into the L2 terminal. Now what we need to do is get a
piece of three core and earth cable obviously I've cut the earth off for
this demonstration, you'll then notice that we have three different colours. What
we need to do is choose a color you would normally sleeve these to indicate
that each one of these wires will be live at some point. So we're going to
take the grey I'm going to put that in the com terminal and then going to take
the black and I'm going to put that in the L2 terminal with the other wire there.
Then going to take the brown wire and I'm going to put that into the other
terminal. Once we've done that it is very simple all you need to do is replicate
what you've done at switch 1 at switch. So again I'm going to put the
grey into con,
the black into L2
and the brown into L1.
So all we have there is the live and switch live in L1 and L2 and then we've used
this cable which is called a strapper and that has just replicated what we have
at switch 1 on to switch 2. We can now reconnect the power. You can see that the
switch is illuminated. If we flick switch one that then goes off so that could be
controlled from switch one we then flick switch two it can also be controlled from
switch two. You can also switch it on with switch 2 and switch it off at switch 1. So it is
very simple to do and it's a lot easier to understand if you actually look at
the schematic diagram.
If we flick switch one the light illuminates. Flick switch one again and the
lump goes off. Flick switch two the lamp illuminates flick switch two the lamp
goes off. Flick switch one the lamp illuminates flick switch two the lamp
goes off. So basically that is how 2 way switching works which is obviously
called 3 way switching in some other
countries. It is very simple especially when you look at the schematic diagrams.
I hope this video has helped and if it has and you haven't done so already
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