in this video presentation we're going to look at the conduit
loop in method and we're going to look at it where we've got two switches
controlling one light Joe can you talk us through a little bit of that yeah so what we're looking
at here is a two way switching method which is a little bit different to the two way switching
method that we've used for our domestic lighting circuits which we've shot a number of videos on
it is possible to use this method in a domestic situation in fact there's a neat trick you can do
if you need to carry a neutral along with it but we'll look at that in a future video
but what we're doing here is we're using what's called either the conduit method or
the conventional method for two way switching so as Gary says we've got our normal two way
switches there's no difference with the switches what changes is the way that we wire them between
the consumer unit and the actual light itself and as we're in PVC singles and we're in a conduit
system we've got the flexibility of putting the conductors exactly where we need them so if we
start off mapping through the line conductor which starts at the top of the MCB so the line conductor
comes from here and it doesn't Joe does it it doesn't end up going straight to the lamp itself
no so we don't take a permanent line to the lamp in most cases in this case there's no connection
in here for that what we do is we take it straight to the first switch position and that goes into
the common of the switch and then out of L1 and L2 on the two switches again depending what switch
manufacturer you're using they might be labeled up slightly differently we then take two conductors
one from each of those terminals over to the next switch what do we call these wires Gaz what are
they referred to as we're calling them strappers and again it doesn't matter if we were in say L1
and L2 this side and then we don't map it through L1 and L2 the other side as long as they go in
L1 and L2 it doesn't matter if they correspond in each of those and then from the final common
of that switch yep from the final common of this switch we go from here we go up to the
light fitting and that becomes our switched live which will control the lamp turning on and off
now we appreciate that this may seem a little bit confusing when we're looking at it here you can't
see where the conductors are going or what they're doing so what we're going to do is move across to
our locktronics board from Matrix and we're going to have a look at how that works in principle
so finally Joe i get to play with the locktronics board in one of my video presentations we see this
quite a lot on your channel is that correct yeah absolutely this is locktronics kit from
matrix which is super handy for demonstrating the principles of electrical science and here we've
got a setup that's going to help us to understand just exactly how a conventional two way lighting
circuit actually operates so do you want to talk us through a couple of bits and bobs we've got
here guys yeah so we're simulating the power supply here which would be the consumer unit in
the job we just looked at we've got the first two way switch the second two way switch and the lamp
and then the returning path which is the neutral absolutely and when you look at these two way
switches just to avoid any confusion here this conductor that you can see here this represents
the common terminal so this one here represents the common terminal and this is just a connected
out connection here so that's just continuous from there to there this whole side here is like the
common terminal and then you've got L1 and L2 L1 and L2 and the common over on that side as well
which then goes off and takes the switch live to the lamp so i'm gonna let you play with this guys
okay should i get to do this very often so how does this actually work we've got the power
supply connected so hopefully if i operate one of the switches it wouldn't matter which one i
operate and the two way system it should bring on the lamp itself so if i operate this switch here
we can see that the lamp is illuminated and our circuit is complete can you talk us through the
circuit that we've got now Joe yeah so what's happened is the conductor is now connected in
the opposite position so what's happening is the current can flow down the permanent line onto the
common of this switch it then flows across the switch contact and down this strapper here so
these two are like the strappers that we pointed out earlier on our rig and then the current can
continue down here onto this switch passes through that contact onto the common terminal which then
connects the switched line conductor and operates the lamp and turns it on so now if we look at
what happens when we operate the other switch Gary what's going to happen when we operate that other
one it shouldn't matter which switch we choose we're going to choose the first switch i'm going
to throw it into a different position and we can see clearly that the lamp now has gone off can you
talk us through that path now please so again you can see here that the electricity is flowing down
this conductor here it gets to the common it goes on to the other strapper now so it's continuing on
to this strapper and you can see that when it gets to this point it can't jump the gap at this switch
the electricity is disconnected here and so there is no current flowing through the switch line
to the lamp and hence the lamp has disconnected so at this stage it wouldn't matter which one of
the two-way switches i now operate the lamp will come on and once the lamp is on it won't matter
which one of the switches operate and the lamp will go off exactly and you can see that this
would be really effective we've mentioned the analogy of a staircase in a domestic situation
perhaps here we're looking at a long corridor maybe a large warehouse where we've got a door at
either end we want to be able to switch the lights on and off from either position you can see it
doesn't matter which switch we operate in fact if we go back there and switch this one over we can
see now that the lamp is illuminated once more as the current flows down this strapper across
the switch contact and onto the switch line so we could make these a lot longer have a switch at one
end of a large corridor or a warehouse a switch at the other end and therefore we could operate
the lights inside the uh the room the warehouse in that way it just shows you how brilliant this kit
is and how simple we took what a minute to set this up and we've easily displayed the two-way
switching method and easily illustrated to both the people watching this video and to our learners
how two-way switching works so joe thank you for that and thank you for letting me use your
electronics board i think this is one thing left to say we hope this video has been some help