i'm back with my rig in which i showed you how to do the feed through the switch method
of wiring a lighting circuit and if you haven't checked that out i'll leave a link for it in the
description or the eye above my head because it's really handy when you're looking at AM2
AM2S and AM2E for the method of wiring two way and intermediate switching to control a
lighting point and that may be something you haven't come across in industry you might
be using the two or three plate method in order to wire that lighting circuit
i said in that previous video that we'd go on and do the safe isolation of this circuit
and the reason behind that is that AM2 AM2S and AM2E you're expected to safely isolate one of
the single phase circuits on your rig in order to facilitate a repair you don't need to make
the repair but you have to isolate that circuit so i've selected the lighting circuit from feedback
from you because it's the one that got a little bit confusing because we've got so many switches
for this lighting circuit do you need to operate those switches when you go to make
your repair the lighting circuit will already be energized and you have to go through the process
correctly in order to isolate the circuit lock it off prove your test equipment and work safely to
ensure the lighting circuit has been isolated so we're going to see that in this video
in your assessment you're likely to be working in a three phase distribution board when you
wire that single phase lighting circuit but here i've just mimicked it with a single phase
consumer unit and as we look in here the important bit first of all is to identify the circuit that
needs to be isolated the first circuit here is identified as light two way and int i'm taking
that as two way intermediate and the second one is identified as outside light so i've already
identified that this miniature circuit breaker MCB is the one that i'm going to need to isolate
in order to turn off the lights however that's the first stage but let's think about the next stage
so we've identified what we think is the circuit that we need to isolate in order to make the
repair on this lighting circuit however at this stage you must stop and inform the customer but
for your AM2 and AM2s and AM2E endpoint assessment it will actually be the instructor you need to
inform so you need to contact them in other words talk to them and tell them that you're going to
isolate the line circuit they do not want you to isolate any other circuits and not a case of
throwing the main switch or inadvertently turning off more than one circuit breaker when you make
that isolation it's very simple as you go with your fingers instead of turning off say a lighting
circuit you turn off two lighting circuits at the same time meaning you turned off the circuit you'd
instructed that you're going to turn off plus another one you hadn't so be very careful when
operating the MCB's that you turn off the one that you're suggesting you're going to turn off
your endpoint assessment you're going to be faced with tables with test equipment on with tables
with your safe isolation equipment on cables switches etc you've got to select the appropriate
equipment so i've spread out on this table here some of the things that could be used for safe
isolation and it's down to me now to select the appropriate ones well i'm going to need a sign
i'm going to need a padlock and i'm going to need a key so let's confirm it is the right key
so will it lock it will lock so i'm happy with those so i've selected those i'm also going to
need to choose something to lock off the circuit breaker well these things here are really designed
for larger devices and main switches i don't think i need the master lock but i could choose either
of these in order to lock it off so whichever one you're most comfortable with that's the one you
select often colleges use these style of ones but the breaker i've got also will facilitate
this style of locking off kit so i'm going to use this one along with my padlock and sign and key
in order to lock off the appropriate MCB for that lighting circuit so we come back to our consumer
unit in this case in the AM2 assessment it will be a distribution board and again be very careful
to select the right circuit i believe it's this one here lights two-way intermediate i'm going to
bring my finger in and only turn off that breaker and i said didn't i previously be very careful you
don't clumsily knock one of the others off your board at your assessment will be a three-phase
distribution board with a lot more breakers in it so i'm going to turn this off remember i don't
know what happens in the installation now it might be that light on the camera has changed slightly
and you now think oh he's turned off the correct circuit but i would actually be standing in front
of the consumer unit or distribution board and not know what's happening in the installation
so at this stage i think i've selected the right breaker i need to lock it off i
bring in my locking off device and this one hooks in the two little holes either side
and you can see there i can't reset it i need to lock it off so i bring in my padlock and undo it
like so it's important you put a sign on it okay you can obviously trip up on your assessment if
you don't put the appropriate sign in place and it might be that they require you also to write the
details down on the back so make sure you fill these in appropriately date name company etc
fill your details in on your sign bring it through with my padlock and then put my sign in place and
close off the log i've said it before you must put this in your pocket you cannot leave it on
the side you cannot leave it on top of the board you must take the key with you so don't leave it
anywhere i'm going to pop that into my pocket i may have isolated the wrong circuit so it might
be that i've chosen the wrong circuit here there is only one writing circuit on your assessment
but i've isolated it and i'm now going to walk out into the installation and see what's happened next
let's think about it we've been standing in front of this case the consumer unit in your endpoint
assessment you'll be standing in front of a three phase distribution board and i've operated the MCB
i've locked it i've put my sign in i've kept the key in my pocket however we've now walked out into
the installation and we're looking at we think ah it's gone off i've chosen the right circuit we
need to think pause on what could have happened as well but what else could have happened is the lamp
could have failed at the same time so the circuit might still be live and we're thinking in our own
mind it's definitely isolated also what else could have happened the lamp could be perfectly fine
but somebody could have operated one of the switches and turned off that lighting circuit
so it's really important as we move to the next stage we believe it's been isolated correctly
however we need to be very cautious when testing it and because we've got these switches we're
going to need to also operate those switches when testing that lighting point because
somebody may have turned it off let's choose the appropriate voltage indicator and test that
works before coming back to here and go through that safe isolation of this circuit procedure
we're going to need to choose the appropriate test equipment to prove this circuit is dead
i've only got one down here but let's think about what they could do at your end point assessment
they could put stuff on the table that's irrelevant for safe isolation or you could
think hang on a minute i've chosen a voltage indicator so that's good but wouldn't it be
easy for the examiner or assessor maybe to leave the shroud separate from the actual tester itself
and we know from previous videos i produced on the channel things to do with gs38 so we can now see
that this tip is way more exposed than the maximum of four mil that you can have under gs38 again if
you haven't checked that video out i'll try and leave a link for it either in the eye above my
head or in the description so you can go back and look in a bit more detail about the requirements
for gs38 let's put these back on so we know now we've got our voltage indicator
correct but we can't just do the following camera we can't just squeeze the ends together and say
oh it makes a nice beeping sound that then for it is working we need to prove this and how do
we prove it for us we're going to use a proven unit we're not going to use another live supply
we're going to use a proving unit because that's the safest way to test it so we're going to test
this before using it by simply probing it into our proving unit and we can see all our lights
have illuminated and we know therefore it is safe and to use so it's working correctly we will need
to check it again at the end but we need to prove it before we do the test we've checked the tips
are good we've checked the instruments good also do a visual inspection of the lead itself
so check there's no nicks or damage in it again at your end point assessment they're likely to
leave equipment out that is non-compliant so have a good once over are you happy with it
if the answer is yes and you've checked it we're ready to do the isolation procedure
so we're going to go into a light point we think it's isolated but it could still be live remember
the lamp could have failed so remove the lamp unscrew in this case my baton lamp holder it
could be that you've used a slightly different style of lamp holder one where the connections
go into the lamp holder again hopefully i've brought one of those on the screen
now we've got a choice but let's have a look at the conductors first before we go about
connecting it so we've got our CPC one neutral and one switching line connection we could probe
in on the top of the connections here and here when doing so and i have practice off
camera with my probes they're no greater than four mill those tips and when i probe them in
i actually can touch the brass work however we saw the lamp was illuminated and i think
it'll probably be easier to get onto the screws that you can see there for the switching line
and there for the neutral in order to prove that this point is isolated we've now got to go in the
safest possible manner so it means probing onto the least dangerous conductor first and then the
dangerous conductor and then off the dangerous conductor and then the least dangerous conductor
so if we go first of all between CPC so that's the least dangerous conductor i probe onto there and i
probe onto my line connection just there you can see by looking at my instrument i have no volts
i now come off the dangerous conductor which was my switching line and off my CPC next i'm going
to test between my neutral connection and my CPC so again the CPC is the least dangerous so
CPC and then onto my neutral connection i've got no voltage off my neutral connection
and off my CPC next i'm going to test between my switching line and neutral so neutral being
the least dangerous of these conductors so i'm going to probe least dangerous conductor
and then onto my switching line conductor
i've got no voltages and i come off my switching line conductor and off my neutral connection i
could have probed in here so if i push one of my probes in hopefully the camera will show here that
i've actually got into that terminal i could do that i could have probed into there as well so
that's firmly connected against my line connection i had a choice of where i wanted to do it
so i could probe into here or there does depend on the style of battle and holder that you've got
that's the first one it could be that someone's left this switch in the off position so of course
i wouldn't have had anything in the switching line conductor because somebody had operated a switch
i'm currently potentially on a pair of steps and the three switches that i've got in my circuit
are potentially some distance away so what am i going to need to do i'm going to need to put the
cover back on my light point i'm going to need to screw that on before i come down my steps i walk
down my steps i walk across the room in order that i operate a switch so i come across to in
this case my first switch i'm going to operate that now if somebody had left this circuit off
hopefully that would have turned it back on and i'll come back up my steps and come back to my
lighting point and i repeat the test again we're going to do this actually we've done
it once so far i've operated switch i'm going to do it again we're going to do it four times
like we did with our insulation resistance testing in a previous video where we did our installation
resistance test operate the first switch did a rental second et cetera and did four times you
can do the same here that's the feedback i've had from students so i'm back at the ladder
i open up my ceiling rose and pendant i'll go through the process again so least dangerous first
CPC i'm going to test it between my CPC and my line connection so CPC in line i come off my
line connection i can come off my CPC i'm going to go between my CPC and my neutral connection
again still got no volts off my neutral connection off my CPC and now i'm going to
go between my neutral connection and my line connection and i have no volts there as well
off my line connection and off my neutral ceiling rose goes back on so i push this back into place
okay i'm wore down my ladder i come across to my in this case intermediate switch but
my next switch operate my neck switch i come across the workshop i come up my steps unscrew
and i go again so this is now the third time i've done i'm going to connect between my CPC
and my line connection i'm going to come off my line connection
off my CPC i'm going to test between my CPC and my neutral connection i'm going to come off my
neutral connection and off my CPC i'm going to test between my neutral i'll test between
my neutral and my switching line connection going off my switching line and off my neutral
i put the ceiling rows back together i think you've got the method now i walk down my steps
i go to my final switch i operate that switch i walk across the room i come up the steps
undo my lamp holder and i'll repeat the process for what now is my fourth time in exactly the
same safe manner we just had so i'm going to test between CPC first onto my line connection
off my switching line connection of my CPC test between my CPC and my
neutral connection off my neutral connection off my CPC at no point have i had any voltage
appear on my instrument i'm going to go into my neutral connection
and i'm going to go on to my line connection i'll come off my switching line connection and
come off my neutral and put it back together before we can confirm to our instructor that
we've completed the safe isolation procedure we must recheck our approved voltage indicator it
could be that this has failed and therefore the line circuit was live the entire time because our
instrument has failed so back into our proving unit push it in like so the screen illuminates
all the way up and that's just a proven unit we've checked that this is now in a good
working order after the safe isolation therefore that lighting circuit has been safely isolated
so we just proved our voltage indicator again on our proving unit before we can tell our instructor
that this circuit is safely isolated and the repair can now be carried out you won't be
expected to make a repair your endpoint assessment but that's the isolation procedure i'm sure this
has thrown up some comments and questions is there an adapter that they've left on the table that can
get to the front of here to make that safe isolation procedure a little easier if there
is then use that adapter we'll be using a batten lamp holder where the conductors go straight into
the back of the lamp holder to probe onto those and if that is the case they've used that style
then you'd probe on in the appropriate positions let's recap some of the points that we had there
so first of all we identified the circuit that needed to be isolated in this case the lighting
circuit we then asked for permission in this case we asked our instructor if we could turn off that
lighting circuit and that's the only circuit that needed to be isolated to make that repair
after being given permission we came back to the distribution board or consuming it turned off only
that breaker didn't use big fingers and turn off more than one breaker and then we locked it off
we placed a sign the information on the sign and we pad locked it off we then put the key
into our pocket and we kept it in our pocket the entire time we then went and saw our instrument in
this case an approved voltage indicator we checked it conformed to gs38 we checked the quality of the
leads we proved it on our proving unit before using it yes it was good to use we came up maybe
a pair of steps we unscrewed our batten lamp holder we took out the lamp we thought that
it was isolated but it could still be live so we worked in the safest manner we went on the
least dangerous conductor first followed by a dangerous conductor off the dangerous conductor
off the least dangerous conductor because remember we don't want to send our tip probes live so if
you went on the line conductor first in this case switching line and it was energized the other tip
would become live we don't want that to happen we did all three we then put the baton lamp holder
back together we climbed down our steps we walked across our cubicle we came to our switch and we
operated that switch we went back up the steps we unscrewed our batten lamp holder we did all three
connections again in a safe manner we repeat the process for the next switch and the next switch
meaning we actually did that safe isolation at the lighting point four times we're not quite finished
we then did one last check on our voltage indicator on our proving unit to prove that that
hadn't failed during the process and at this stage with it locked off sign in place key in pocket
we can now suggest to our instructor that we have safely isolated the lighting circuit and
the repair can be made if there's any feedback from your am2 or m2s that can help the people
in the comments please leave them and can you answer some of their questions
i'm just getting feedback from the community and making videos to try and help you if in some way
there's another little bit of detail that can help anyone doing that assessment please leave
it below and i will thank you for those but as always i hope this video has been some help