So Joe in this presentation we're going to look at
the connections within the 17th edition amendment
three consumer unit best practice to layout conductors and the identification of those
conductors we know as we're developing into the 18th edition we're going to see things
like our RCBO's become commonplace as well as the introduction of what as well as looking
at the introduction of surge protection devices now this is something that it's not a controversial
area of the Regs and it's not a new area of the Regs but it's something that's developing
isn't it and i think particularly industry is developing its understanding of surge protection
where and when it's to be used uh when you don't need to use it when you can avoid using
it so it's an interesting kind of area under development and you can guarantee there'll
be lots more information on this coming through so we're just going to have a very brief chat
about that as we move through the video and we're seeing that they're calling them 18th
edition distribution boards or consumer units now where they're actually looking to integrate
those in even though we know in a domestic dwelling they can be avoided so we're going
to bring the camera in we're going to take the consumer unit cover off we're going to
talk about the sticker that's on the front of it and we're going to look at the layout
of these conductors in relationship to the circuit breakers and our RCD's within the
consumer unit so Joe the camera's in nice and close before we actually take the consumer
unit
cover off and have a look at what's going on inside there we have got one of the stickers
we expect to see on the front of the consumer we're going to show a later video with the
stickers expected on the consumer unit can just explain what's changed about this sticker
yeah so this is the sticker indicating to the property owner or the the dweller that
it's very important that they check that the RCD is operating by pushing the test button
on the RCD here on a regular basis now the label actually indicates a bit of a significant
change under the 18th edition so we've gone from testing quarterly as we were in the previous
edition so every three months to now we're instructing the homeowner or the the property
manager that they need to test six monthly so we've gone from every three months to every
six months so that's a small but significant change that's occurred in the 18th edition
and from our learner's point of view that's often an exam question is that right yes that's
correct so it's worth knowing at this point that that is the case so then Joe we're going
to look to get inside this electrical enclosure we can clearly see the tails are not connected
to the supply because this is a mimic installation however we're still going to approach it as
if it was an energized installation when we're going in to have a look at it so as we open
up the consumer unit lid to expose the circuit breakers RCD's and the main switch so this
is a linked main switch or double pole switch what's the process we're going to go through
before we actually operate the switch for means of isolation yeah so what we want to
take care of here is we need to acknowledge that this main isolator is not really designed
to be operated under load in other words if we had a lot of current flowing through this
isolator we wouldn't necessarily want to go straight to that there as it can cause arcing
and other issues so the kind of preferred method for isolating a consumer unit that's
under load is to go to each one of the individual circuit breakers and to turn them off one
by one before we isolate the main switch so do you want to demonstrate that for us Gaz
yeah so we were knocking off individual circuit breakers we'll be then knocking off the RCD
circuit breakers and then the RCD and then we'll do what joe and now we've got to this
point we've disconnected all the load from the consumer unit so at this point we can
now operate the main switch and that could be safely isolated and we can remove the lid
and get to work same process applies when the there is a separate uh isolating switch
within the tails itself we'd still go through the same process when we'd operate the circuit
breakers our RCD's this switch and then obviously the remote switch as well absolutely one more
point just to watch out for is that once we've isolated this once we've turned it off of
course it's very easy for someone to come and switch this back on again so we'd want
to make sure that we locked this out put a tag on it instructing what was happening so
that no one came and switched that on accidentally remember in this video is all about the layout
of the inside of the consumer unit the position of circuit breakers and not necessarily a
safe isolation video and you can see that in other presentations that we have produced
so Joe in this mimicked installation we need to get inside the electrical enclosure and
if states an electric enclosure need to be entered by what means so it can only be entered
by means of a tool or a key and so in this case we're using a puzzy screwdriver to remove
the fixing screws once those are undone that can then be slid up the front there well joe
we got a lot going on in this consumer unit and i'd like to think at this point anyone
watching the video who's a DIY home enthusiast he would understand or she would understand
that this is the stage where an electrician somebody of competence is actually going to
be working and we wouldn't be dibbling around in here as a domestic household owner absolutely
yeah there's a lot of stuff going on here it's easy to make a mistake to get something
put back in the wrong place which can not only cause malfunction of equipment but could
also cause injury or even death so this is the stage where yeah once we're looking at
this we need a proper qualified electrician in the building okay then joe from a learner
standpoint now we're going to go through what we've got laid out here coming up with some
of the key areas and key things to remember as they go through their training and move
towards being an electrician in the electrical industry so first of all we've stated this
is the main isolation switch often called a double pole switch or a linked main switch
can you explain which conductors that is isolated for me joe yeah so if we look in the top of
the switch here you can see that we've got an incoming line and an incoming neutral now
these are both classed as live conductors which means that when we operate this main
switch here we're breaking both the line and the neutral coming into the installation so
now all of the conductors all of the live conductors all of the neutrals are all disconnected
from the incoming line and neutral so joe we've got two RCD's in circuit here and they
are ac type RCD's and we're going to produce a video later on about the limitations in
the modern world of an AC RCD which type of RCD's are we really looking to move towards
we're now looking to move towards type A RCD's there's numerous reasons for that and again
like Gary says we're going to get into that in a slightly different video a more technical
video but it's worth starting to note because this is something that perhaps we've not thought
about very much before this little symbol here that shows as a sine wave the ac waveform
that little symbol will change from device to device and we need to start familiarizing
ourselves with what that means so just keep a watch out for a future video covering that
material we've discussed at length on other videos and with our learners that the RCD
is offering additional protection to offer additional protection the RCD rating must
be rated at 30 milliamps or below the actual rated value of the switching mechanism within
the RCD is 80 amps for our learners we're concentrating on this 30 milliamps and below
in order to offer additional protection and both RCD's are rated the same at 30 milliamps
can you explain why we've got two joe yeah so what we're looking at here is this this
is sort of a more 17th edition kind of compliant board going back a little way when RCD protection
became something that was a more stringent requirement especially in domestic installations
there was an issue brought up with if we just have one RCD protecting all circuits we run
into a real problem with what used to be called discrimination on the 18th this is now called
selectivity the idea being that if we get a fault on one circuit that one fault on that
one circuit should only trip and isolate the circuit that the fault is on now at the minute
we've got a situation if we only had one rcd cover in the whole installation a fault on
any one of these circuits would disconnect everything now obviously that would lead to
poor selectivity and it would mean that the entire property could be plunged into darkness
no electricity because of a fault on one circuit now what we've got here is kind of a halfway
solution because we've got an RCD covering half of the circuits in the property and an
RCD covering the other half of the circuits in the property and there's something significant
actually and this again is it's quite a nice subtle point here but quite a kind of important
one that again separates you know sort of the professionals out from the amateurs really
because how are these circuits arranged across these two RCD's guys so joe what we end up
doing is mixing and matching the locations of circuits across our cds so we've got an
rcd here and we're mimicking circuits and we've got an rcd here and we're mimicking
circuits so if circuit here number one was mimicked to be an upstairs ring final circuit
we wouldn't want when this rcd to goes off to turn off both the upstairs sockets and
say the upstairs lighting so we're going to position the upstairs lighting not here we're
going to have these as the downstairs lighting against maybe the upstairs sockets and we
swap the process when we come over here so what we find now that this is possibly now
the downstairs ring final circuit and this would be mimics a as the upstairs lighting
circuit so in the event of losing one RCD you get the residual lighting from maybe table
lamps TV's etc when you lose main lighting an opposite way round when we lose it in a
different area yeah and obviously this is not a perfect solution to the issue of what
we now call selectivity because you know we've not got perhaps two showers in the property
we've not perhaps got two cookers in the property however it's kind of a halfway house solution
isn't it so it's not too bad but obviously we're constantly seeking to improve installations
we're constantly seeking to improve the industry so what really would be the absolute ideal
solution in this instance guys is to have not RCD's protecting multiple circuits but
to have RCBO's and this is the larger version we know they've miniaturized them it's also
a c-type probably not uh applicable for a domestic dwelling it's just one i've just
pulled out of the cupboard but if we move towards our RCBO's in the event of it causing
a fault on one circuit say to earth we're just going to isolate just this one circuit
we have got more test buttons to press so under the 18th edition we know joe we're going
to be doing what with those uh we're going to be testing those every six months as i
believe we mentioned earlier we are so joe let's have a look at some of the rated values
in amperes of the overcurrent protection devices and relate it to the type of circuits we're
mimicking here in the installation so as we just said there this is 32 amp type b all
the breakers in this distribution board are type b the type is matched against the in
rush style of currents given by the loads and we know with things give us an example
of some things that may alter the type of breaker that we're going to use yeah as homes
become more and more modernized and we get more and more equipment being installed in
there we might occasionally have inrush issues with things like air conditioning units if
you had a lot of led lamps of specific types you might get a bit of inrush current there
so we'll release a video in a later date that describe RCD type differences in a bit more
detail but it's all to do with basically the type of load we've got connected now generally
in a typical domestic dwelling a B type will generally be okay but it must be matched against
the type of load that's going to be installed that's a fantastic piece of information joe
again mimicked installation for us so 32 amp type B breaker we've mimicked a ring final
circuit but we've also labeled the conductors with the number ones and by the looks of things
now we've got two neutral bars here Joe um any reason why we've got two yep so we've
got two neutral bars because we've got two separate RCD's so again very briefly we've
covered this in a different video but an rcd works by monitoring the current flowing uh
down the line and back down the neutral and as long as it seems this sees the same current
in both it's happy so we need to have a separate new separate neutral bar for each of the RCD's
so this one relates to this neutral bar this RCD relates to this neutral bar because if
we connected these all onto the same neutral bar the RCD's would be constantly tripping
out and just going back to the numbers as guys were saying we can clearly see there's
a relationship here so we've got this one labeled up with number ones and where do we
find uh what else do we find labelled up with those number ones there so we've got the neutrals
described here but also the circuit protective conductors in the earth bar so when we're
taking out circuits or working on circuits it helps us identify the circuits we're actually
working on yep absolutely now as we work our way down here guys okay it's of note to see
that there's actually a gap here where there's no circuit installed so why have we got a
circuit breaker installed there when there's no circuit coming out of it this was practice
given to us by Luke Wichard what we tend to do is have blanking plates put into distribution
boards consumers units however what he said his practice was to actually give yourself
an opportunity in the future to go back either to use a circuit breaker that was already
there at the right ampere rating or to remove it and jiggle those around let's just make
it very clear now before we get comments this is not a requirement by the regulations this
is just something that's been demonstrated to us that we quite like the idea of obviously
there's downsides you've got the added expense of a couple of breakers but actually this
creates a much kind of more thorough installation we think this is a quite a good practice to
get involved in so not a requirement but again it's something that we quite like and we'd
probably put into practice if we were on site when we go we absolutely would another thing
to note is that from the main switch working away and from each rcd that we tend to go
for best practice again not a regulation to go from largest to smallest so we've gone
32 amp ring final circuit a breaker not being used then we've got a breaker rated at 20
amps again at type B with a 2.5 mil cable number three number three number three and
then we go six amp and six amp for two probably light in circuits being mimicked here so we
went down 32 32 20 6 and 6 in descending order yeah and the reason for that really is so
that uh the largest amount of current runs across the least part of the discord of the
bus bar down here now again this isn't a regulation it's not a requirement this bus
bar is rated to take the current that we're running through it but again it's just standard
practice good practice to do this so that the largest amount of current which is running
through the larger breakers generally speaking will flow through the shortest amount of buzz
bar before it exits into the RCD there it's a very good point joe and we've got exactly
the same here in this half of the installation we go 40 amps 32 32 16 not being used and
a 6 so again we've come down in order of size of circuit breakers we've got some issues
here probably we couldn't find the right size number for this one this should have been
numbered six okay i don't think it's a big issue when it's a 10 mil cable and then we
get confused with it if we were removing it and then we go seven eight nine's not being
used in 10 and we've replicated it on both the CPC's and noting that we've now moved
to
the different neutral bar here joe yeah absolutely so joe we've already talked about some of
the things that's making a consumer unit evolve over time whether it be moving away
from AC RCD's to maybe A types RCD's in the future we're also seeing in the early stages
of the 18th edition the actual in domestic dwellings where we're considering it might
not be required in single dwellings that SPD's are now appearing in the consumer unit as
increased best practice do you want to show us what that would look like yes so surge
protection as you say is one of those areas that the industry is kind of still coming
to grips to it's by no means new technology this has been around uh for a long time but
it's something that the electrical industry at large is is still sort of getting used
to under the 18th edition um like Gary says while there's not necessarily a requirement
in place uh just yet for a single domestic dwelling when you look at the cost of surge
protection against the cost of all your electrical equipment in your house you know there's no
contest really in terms of the the cost implications for providing this protection and we're starting
to see now that manufacturers are actually starting to install search protection devices
into consumer units as kind of a a standardized practice moving forward so actually we might
get to the point where we kind of just buy a consumer unit and they say do you want surge
protection for an extra x amount of pounds well yeah let's just put it in there and we're
seeing the SPD perhaps being inserted inside into the consumer unit followed by a row of
miniature RCBO's it's the practice that we're looking at yeah so that's just a little run
through of what we expect to see within the consumers unit probably highlighting some
best practices as well but as we move into the 18th edition and deeper into it and we
evolve what a consumer unit looks like in domestic dwellings we're going to see some
radical changes over time to agree with that joe absolutely yeah and it's one of those
things you know um we started off with you know sort of fused links fuse wires and that
was replaced by sort of cartridge fuses and then as time went on we got MCB's and now
we've got RCD's RCBO's it's it's just the natural
progression of our industry and really it's
something we should be embracing because it's all about that constant striving for improvement
for professionalism and for safety as well for you know the safety standards in our properties
we want to make sure that we're leaving a property safe and sound so that customers
don't get hurt by work and before we exit this video i'd like to reiterate this is the
area and domain of that qualified electrician and they should be the people poking around
and making the adjustments required in electrical installation we've also got a separate video
where we talk about the talk settings okay and setting up our talk screwdriver as well
so feel free to check that one out as well so joe that's looking at some of the best
practices that we can have for laying out conductors within a consumers unit and we're
looking at perhaps going over to our RCCB's moving away from our RCBO's and you also suggested
that we're looking to put in yeah some surge protection devices so we've got an example
of one of these here and we can see that shift now can't we we're pulling away from the 17th
edition amendment three of the Regs and now we're looking at the 18th edition and we're
looking at the changes that will start to take place within consumer units like this
one and perhaps on a larger scale in more industrial settings as well so Joe should
we do it yeah we hope this video has been some help