so continuing on with our wiring diagrams we're at the stage now where we're doing the intermediate
switching so this is where we've got three or more switches controlling a lighting point as
long as you have a two way switch a two way switch the switch in the middle here is the intermediate
switch you can have as many intermediate switches as you like as long as at each end there is a
two way switch so we're using three positions for this drawing but you could have an infinite number
depending on how many intermediate switches you put in circuit key question that is sometimes at
multi-choice exams how many intermediate switches can you have it's a limited number of intermediate
switches in order to control the lighting point as long as each end has a two way switch
again this is a wiring diagram and as we said before the connections within the ceiling rose
so if we look here within the ceiling rose itself with our block of three for neutral block of three
for line block of two for switching line and our earth terminal for our CPC's exactly the same
here in the back of the lampholder block of three neutral block of three for line block of two for
switching line and a earth terminal for the CPC's this here will help you wire in those accessories
as with the switches we looked in the previous video the two-way switch common L1 and L2 or
terminals to that suit sometimes you've got L2 and L3 but you've got a common or one terminal zone
and two other terminals okay so that's there so exactly the same this diagram here will help you
connect up a two-way switch and now we introduce the intermediate switch it's one gang so there's
only one switch on it when we turn it over there are four terminals making this an intermediate
switch they can be labeled L1 L2 L1 L2 they can be labeled in this case L1 and L1 l2 and L2 and i
have seen labelled L1 L2 L3 and L4 it's important from the point of view only that a cable coming
in the top goes in here and here so the brown and grey of a cable coming in goes in the top
and a cable brown and grey goes out the bottom and not across the side so we won't bring a cable in
so this cable when it comes in we use the brown and gray either in the top two or the bottom two
and the one going out goes in either the top two or the bottom two and we'll see that in
the drawing and definitely not across the side so the brown and grey of these wouldn't be connected
across here that's a common mistake when wiring up intermediate switches that we make the connections
in here incorrectly we'll do the drawing correctly and if you follow the two together you should be
able to wire up the intermediate switch with ease take it back one stage to start with we
looked at our two way switching in our previous video and it's exactly the same wiring diagram
apart from this section here we'll introduce another switch the intermediate switch goes in
here so again if you've got two way wiring circuit you can make an easy adjustment by
adding an intermediate switching and that's probably what you'll end up doing in the workshop
so exactly the same so good recap for us fuse neutral link earth terminal for CPC
probably won't help you with the connections in the consumer unit but again they're there these
connections and these ones in the switches will be helping you wire up in the electrical workshop
we're gonna bring a cable from the consumer unit it to a light fitting
using one millimetre squared PVC PVC twin and CPC cable so we've got a line our neutral and
a circuit protective conductor we'll put those in first remember you will be using a rule i'm
not only doing it freehand and i'm also doing it upside down so the line coming in as always is
going to go into the center block of three the loop in terminal so it's going to go into this
center block of three the loop in terminal and it doesn't matter which of those holes we choose
again try and make it as easy as you can for the drawing so i'm going to use this one here
out of the loop and it's going to join up to the line conductor
between here and here again you'll need a rule so our line conductor comes into our loop in terminal
let's take next are neutral again the block of three here any of those three can be used for
neutral connections so as we look here any of those three can be used as our neutral
connections it doesn't matter which one we go in it's a brass block with three holes in it
so let's come out of this one here and bring our neutral connection around
as best we can straight as Gaz can do it there you go so that's our neutral connection in
and then our CPC comes out of our consumer unit at the earth terminal
and he's going to come into this terminal here we look here there's two on this one there are CPC's
to go in and on this mate there's just the one CPC terminal remember we've talked about it previously
all the accessories in the workshop we're going to be working with a plastic including the boxes
the CPC is there in case we change it for an exposed conductive part so let's bring the CPC in
like so and again some of my learners do like to just put a slight strike of yellow down there
still only one cable it's not two cables you know because i'm doing two lines
and then it becomes my CPC so what we've done there is we've brought in from the consumer unit
permanent line neutral and CPC line neutral and CPC we connect it into the loop in terminal for
the line the neutral terminal for our blue neutral conductor and the earth terminal for our CPC
and we're going to bring the cable down again as if we were going to a one way
switch or a two way switch in our previous drawings exactly saying this cable comes down
from the light to the switch we're going to use twin and CPC cables mentioned in a previous video
but somebody commented we could use twin brown here and we do often at Tresham use twin brown so
rather than using blue brown and CPC we use brown brown and CPC i've kept these drawings using twin
and CPC because you see a lot in industry the twin and CPC going down to a switch and identifying
the blue conductor differently and we'll talk about that again and also other colleges tend
to use it as well so i'm just trying to push our learners our learners will probably use twin brown
they'll be able to adapt the rest of the world is probably using twin and CPC and identifying this
one so again it gives my learners that that mental push to think hang on is this a neutral or is it
a switching line on the drawing what am i using in the workshop etc but this could be twin brown
and CPC so again this cable is going to come down from the ceiling rose to the first switch
and it will be a two way switch let's start first of all by doing CPC so CPC comes down
connected into effectively the plastic box we've got in the workshop so that'll be the
plastic back box it'll go into if for some reason at your college you're screwing down
metal boxes in order to hold your switch fronts on you can note there is a CPC terminal in the back
and the CPC would go into there because obviously this is metal Tresham college we're using plastic
back boxes there is a CPC terminal in the back of the plastic one just to hold the connection in
place of course plastic doesn't need to be earthed the CPC is there in case it's ever changed maybe
we change the switch from metal switch etc so it brings the CPC down see if i can line
these up a little bit better than i did in my previous drawing so one of these is going to be
the switching line and one of these is going to be the permanent line so if i take this one here so
the blue one we're going to come out of either L1 or L2 and connect it into my switching line
connection my permanent line is going to come down and it's going to go in either L1 or L2
like so remembering that this is not a neutral so this cable here coming down to the switch is not
a neutral it's a switching line conductor and needs to be identified by inserting a piece of
brown sleeving over the blue when you terminate the ends and to show that we're going to use a
brown uh marker pen to show the sleeving on it so that's to identify the sleeve it's
important you put that on that is not neutral it's a switching line and it goes in L1 or L2
so again it doesn't matter which one of the two terminals as long as it doesn't go in common
it can go in either of the other two terminals it doesn't matter so that brings that cable our
one millimetre square twin and CPC down to our first switch and we're just going to link them
together using three core and CPC cable so this three core and CPC will go from the two way switch
to the intermediate and a separate cable from the intermediate to the other two way switch
so that's what we're going to do next a little bit difference here because this symbol here doesn't
actually appear on the intermediate uh switch so we've just got the four terminals one two
three four and then this is sort of block here of drawn in which obviously doesn't appear on there
that is simulating depending on your college a connector block this could be a connector block or
it could be what depends how you want to say it Wago or Wago a Wago connector or it could be
a through crimp or splice so that picture here can be any of those three
it's just to join the cables between it doesn't no connections for that conductor just pass through
and we'll look at that in a second so we've got these colours now brown black grey and our
CPC let's put our CPC in first make it nice and simple so our three core CPC goes between here
and again if we want to strike a little bit of yellow onto it we can
so our CPC comes through we're now left with brown black and grey i like the brown which is
the permanent line here to be the permanent line coming down so that brown one comes from here
i remember what i said about the switch the cable coming in will take either doesn't
matter which the top two or the bottom two so this brown coming in from the three core
has gone in the top one doesn't matter which one of the two it goes into and then we've got
the other connection here which will be the gray so i take my grey connection i come out of here
and i go into there of my intermediate switch leaving just my black cable my black cable
is going to go from the common here and it's going to go through the connector so maybe we're using a
Wago connector so it's not going to be connected into the actual switch itself it's not going to
be in any of these terminals it's going to be separate floating around in the back of the box
but because these are switching line conductors the black and the grey we need to identify them
accordingly again to represent the brown sleeving here we're going to put a little
brown mark against the black one brown marker black one here brown mark against the grey one
and brown mark against the grey one there so they're all identified as switching line
conductors so that's the three chord from this two-way switch we came out of common with the
black doesn't matter which way around we did L1 and L2 we had the grey and the brown cables coming
out with the corresponding brown and blue from our twin and CPC cable which was from our light down
CPC's are connected together and that three core has been inserted we repeat the process now coming
down maybe i'll start with the black this time so my black is going to come out of my connection
floating around in the back of the switch and it's going to go into my common terminal
and then we've got our grey i'm going to pair them off so effectively the bottom grey and brown come
out in the same positions as the top one but it wouldn't matter so it wouldn't have mattered if
this one was brown and this one was grey but we all like to draw it and connect them like that
so this will be grey and this will be brown so we bring out our grey conductor from our three core
and then we bring out our brown conductor from the intermediate switch down to our two ways like so
again we need to identify the switching line conductors put our brown sleeving inside
each of those positions like so so now we've got a three core cable we just need to make the
CPC connection to complete it bring down our green and yellow cable again just strike a little bit of
yellow against it so from the intermediate switch we've come down now with another three core to our
next two way so within our intermediate switch we've got a brown and grey in the top from one
of the cables the bottom we've got a brown and grey from the other cable coming out the bottom
and we've got this cable which is our black one just being connected in the back of the actual
box floating around it's no connectors only four in here the Wago connector will pass the common
loop through our CPC's are connected as usual and there are connections so that becomes our two-way
and intermediate switching remembering we said we can have as many intermediate switches as we like
so if i insert another one here i just break the brown and the grey and join through the
black cable exactly what i've done here as many times as i like before i get to the final two
way switch or the first two way switch so it goes two way switch as many intermediate switches as
you like followed by two way switch in order to control the light and circuit
that's what we're going to end up doing in the workshop consumer unit light and three switches
with the cable connections as shown here in this drawing and this drawing will help you make those
connections but you might be lucky enough to extend your circuit so again you might find that
this is in area number one and then we carry it onto into a second area or further down our wooden
board and we repeat maybe a one way or two way or a two way intermediate circuit again in order
to carry on exactly the same as we did before we take out our brown and we go into the next room we
can take out our blue neutral and go effectively along our wooden board into the next room and we
can take our CPC out and we continue the process on again so what we're doing there is taking
a permanent line goes into loop of the next ceiling rows a neutral
into the ceiling rose neutral terminal and the CPC into the earth terminal of our next ceiling rose
so we come into our next ceiling rose here and we just repeat whatever process we need again so we
can do a one way two way or an intermediate line so this just needs completing now with the cable
which is the flex okay so if we bring out our brown onto our lamp and our blue onto our lamp
if the circuit is in the on position depending on our switching sequence our lamp will illuminate
one thing to bear in mind on your intermediate switch is either in this position where it passes
straight through and you can see the diagonal lines it actually switches on the diagonal so
it goes from the gray one will switch across this brown one at the same time this brown one switches
across with this grey one when you operate the switch so when you're operating it's either
straight through or across the diagonal that's something we'll cover when we actually physically
wired it up into the classroom or in the workshop we'll talk about this interconnection in order to
find the position whether we're on or off you can work it through yourself moving the blades of the
switches i did in the previous video but just remember this one goes across both diagonals or
straight through from its switching position so as always i hope this video has been some help