in a continuation of videos i've been looking at wiring lighting circuits today we're going
to change tacks slightly and that means there is a different downloadable link so in the description
there is a link that takes you through to this document here which can be downloaded
and used to run alongside these videos with this time going to be looking at using
pvc singles so single insulated conductors that are stranded for greater flexibility
because they're pulled in through things such as metal and plastic conduits and trunking systems
so this time we haven't got any outside pvc as we've seen in previous videos
and in previous videos we were using pvc pvc twin and cpc or twin and earth cables but for
this conduit looping method we don't need this type of cable and we're going to be working with
single insulated cables which means we have a greater flexibility of where our conductors are
going to go and they go to exactly where we need them to go and not be trapped inside a cable which
has other conductors that might not be needed at the location we get to so this is downloadable
within the actual description itself and it talks you through a little bit of an overview on using
pvc singles to wiring lighting circuits remind you that the minimum cross-sectional area of
the conductors is 1.5 millimeters squared and then we've got some wiring diagrams or circuit
diagrams whichever way around we're going to look at them so we've got some circuit diagrams
we've got an exercise here that maybe your college lecturer might want to use or you might want to
build this at home i've built it in plastic conduit there are other videos on the channel
that show me wiring through this system using the conduit looping method and that's in my lighting
circuits and my playlist called taking the feed or supply to the switch so in both those light
and circuit playlists and you'll recognize that board when you see it i've got some test sheets
for you in case you wanted to fill those in again there's loads of videos on testing those circuits
as well as a marking criteria if your college lecturer used them and then we've got these which
are wiring diagrams okay we're going to look at these through a series of videos on the conduit
loop in method and we'll work eventually with this one at the back creating different scenarios
so let's first of all look at these ones here which i've classed as being circuit diagrams
so these circuit diagrams here give us that overview of what we're going to be
doing with our conductors and can help you why the circuits are also can be used as a wiring diagram
we've got a line and neutral here on our drawing however i haven't shown the cpc connection
because the cpc actually will take the shortest and most logical route through the system and not
necessarily one that the drawing can show so if we go back to this one just here if my cpc came out
and went say to here we then drop a cpc down to the switch now if we went on our drawing we look
that we go to the switch first and then the light that doesn't make logical sense does it because
actually the cpc would have been dropped off at the light first and then go down to the switch
itself so i'm going to leave off the cpcs off this drawing and just concentrate on those live
conductors so here we're simulating as if it was in the consumer unit that we've got our fuse and
our neutral link so this would be our neutral bar within our actual consumer unit this would be the
six amp possibly circuit breaker that's feeding the lighting circuits we've got three colours of
pens that we're going to use i'm not going to over strike it this time with yellow as i've done in my
previous drawing so i'm going to use the green as a cpc blue neutral and brown as a line conductor
nice and simple one-way lighting circuit one-way switch a light fitting come out the consumer
unit and we're going to wire it through remember they're in pvc singles and can go anywhere we like
so our line conductor will start in the consumer unit and it's going to go put it
through the breaker so it becomes effectively looks like a symbol for a rewardable fuse
but it's a fuse so we come through to here and we connect it into the common terminal of our switch
so if we look at our one gang one-way switch we're going to bring our permanent line connecting
straight into the actual common itself so the line connection comes straight into the common so in
here into the common and then from L1 we're going to come out to feed our lighting point itself
so we come out of the L1 terminal and we feed onto our lamp itself hopefully you're using
a ruler i'm doing it freehand and i've caught the side of the omega symbol there okay so make
sure you get it in the right position so line comes through the switch and go straight to the
lamp itself that makes logical sense and where do we need the neutral to appear we need the neutral
to appear on the other side of the lamp this is a symbol for a neutral link and we'll only need
the blue to be either side of it and no line straight through it lots of my learners make
that mistake so we're going to bring that straight out of there out the neutral link
like so simple more of a circuit diagram than it is a wiring diagram
the line goes to common common of our light switch from L1 we come up to our lighting point and our
neutral goes directly to our light itself that makes logical sense doesn't it that we've got
that route taken now a cpc will need to appear at both the switch and the lighting point
and again when you're wiring it you will take the most economical route round with those
we're going to work with these so don't worry if you haven't quite grasped it at the first attempt
we're going to come back to this and look at it apply it in a wiring diagram as well so
from the consumer unit the line goes to common a separate cable obviously from L1 comes up to
the lamp the neutral comes in this case from the consumer unit directly straight to the lamp itself
which does mean that this type of light fitting that has the loop in terminal in it so we've
got a loop in terminal there so that loop in terminal there isn't needed in this system
because we're going to be using the conduit loop in method where the supply goes first
to the switch and we only ever end up having a switching line up of the light fitting now i
know a lot of colleges still use these when wiring in the conduit method but remember you don't need
the center block there is a light fitting that you can use that only has three terminals that would
be better suited for this system and hopefully your college are using those style those will only
have switching line and neutral and a protective conductor so a cpc terminal within them hopefully
i've shown one on the actual screen itself so you can see what that looks like as well so that was
our one-way circuit diagram if we move on let's have a look at what happens when we go for two-way
so we bring this one in here again we're showing it from the consumer unit and we'll look at how we
can pick up the supply when we've got not a route to the consumer unit for it when we're doing our
wiring diagrams again our permanent line is going to come from a consumer unit to a common terminal
we're going to have two cables linking across L1 and L2 here which we call strappers and then
from our comment of our second switch we're going to go directly to the lamp and obviously we come
back around with our neutral so we're now using our two-way switches so if we look here we've got
a two-way switch with our common terminal L1 and L2 but this time unlike previous drawings when we
used our three core cable if you remember back on those type of ones often um we'd have to identify
these with brown sleeving wouldn't we because the grey and the black are actually switching
line conductors but as we wire in this system in singles we can make those conductors between
the switches all brown so we don't need any brown sleeving we can identify them by the colour which
is brown for switching line line strappers etc so we can actually use brown conductor so there's no
need to identify those from the consumer unit then we're going to bring our line conductor
too common so we bring our first single cable in which is our permanent line into the common
connection we're going to come across from L1 L2 so we're going to take them from L1 and L2
to L1 and L2 of our second switch and they're going to be our strappers so our strappers come
across again they're in brown singles and then from the common of our last switch we go across
to our lighting point itself making sure we strike it against the right part of the lamp there
so there we go we've gone through that to make it work we'll obviously need a neutral to make
it safe we'll need a cpc cpcs won't be drawn in on this one but we'll bring our neutral round
bring it through our neutral link remember no line through it we just go either side of the neutral
link okay let's see if it's on then that'll be the next thing for this one is this circuit currently
in the on position well let's follow it through we've got a neutral this side so that's fine
the line connection comes into common it comes down the blade of this switch here
comes along this strapper here but this blade is in the opposite position so this blade is
not made here so the lamp would not illuminate these are two-way switches and we're used to
seeing them at home possibly bottom of the stairs and top of the stairs turning on a landing light
and if the light is off we know if we operate either switch it no matter which
one you operate it will come on likewise if it was on whichever one you operate will go off
so it won't matter now which of these switches that we operate it will come on so let's use
this pen here as if we've now made that line there we've moved that into this position let's follow
the line through it comes down this blade it comes up here and it would illuminate the lamp okay
likewise if we go back to our original one we can see that it's off if i was to operate this switch
so i move that blade to there we come up along the strapper along here and the lamp will illuminate
so we can easily see there that the two-way switching has been done we've used all brown
conductors for our line switching line strappers whatever you want to call them
and our neutral is obviously in blue our cpcs would go around in a logical pattern and again
we'll work with that in a wiring diagram to see how that circuit can be wired logically
through a conduit system in another presentation let's move that on now so you know where we're
going next i'm going to take you to two-way and intermediate switching so all we've done now is
add in an intermediate switch so if we go back to our original drawing you can see they look very
similar but just an intermediate switch has gone in here in other words it's breaking the strappers
so that's been inserted in there like so and again all our conductors will be brown for our switching
line line and strappers as well as a blue neutral and we remember the intermediate switch actually
switches across ways and we'll talk about that in the classroom for its actual position but you can
have a play around with this one when we've wired it in with our colours to work out whether the
lamp is on or off so our intermediate switch just to remind you has four terminals and we
can use all four of those but if you remember in other videos we've done using twin and cpc cables
we ended up putting the black conductor in a connector within the intermediate switch
but in this system we don't need to because we're only going to be using pvc singles
which means we can take just the conductors we need to the location in which we want them
let's pull those in then so let's bring our line from our consumer unit through our over current
protection device straight into the common of the first switch we bring our strappers
into our intermediate switch from our outgoing side we come out to our next intermediate switch
there's nothing in and out on these but there is a set of two a set of two
but just remember we've rotated it round so if you end up using this as a wiring diagram
that we're not putting our strappers across these here and here it's the top two and the bottom two
we've just rotated that switch around so we come from the two-way switch into either the top two
or the bottom two doesn't matter which way round we have it and then we come out of the
top two or the bottom two to the next one so effectively our switches are being laid
down like so so that'd be the first two-way switch and that'd be the intermediate switch L1 and L2
come in either the top or the bottom of this switch depending on which way round you have it
and not across the sides and some of my learners have have got that intermediate switch wrong where
they've actually come in with a set across the sides rather than top and bottom hopefully that
will make logical sense to you if you don't just whip back and just listen to that again
and then out of the comment of the last two-way switch go directly to the lamp in order to make
it work we'll bring our neutral through here off our neutral link into that position there
and there's our circuit diagram now for our two-way intermediate or which we will use it
as a wiring diagram as well in other videos so this this circuit diagram here can help us
wire the um conduit system lights but we're going to have to work out our cpc route etc as well
let's do one of them i hope this video has been some help