so in this video presentation we're going to look at the three-phase safe isolation
procedure a procedure needed for AM2 and AM2S as well as working as a contracting electrician
we're going to safely isolate this distribution board to behind me we're going to secure the
isolation and we're going to prove its dead with a proven unit and a voltage indicator however in
the classroom before starting this exercise we have discussed things like permits to work signs
and barriers and other procedures that need to be considered before the safe isolation
process begins this video is at the point where we're now going to carry out a safe isolation
we want to carry out the safe isolation in the safest possible manner so it means we won't be
going in and just throwing the main switch here and in this case we also have a remote
switch so this switch here will also isolate this distribution board we have other switches around
the workshop that also can be used for isolating the distribution board so we're going to work in
the safest possible manner exactly the same as we did with a single phase consumer unit we're
going to isolate individual circuits first so we end up turning off the main switches with
no current being drawn or hopefully no current being drawn so what we don't want to do is start
throwing this switch with all of the circuits currently energized so let's go about that next
so we're going to turn off individual circuit breakers reducing the current down at the main
switch will obviously isolate expected to be zero so we've turned off all of the devices within the
distribution board we next throw the main switch which can be tricky ok and we've thrown that off
load so there's no current going through it and as we have a remote switch away from the consumer
unit or distribution board in this case we can turn that one off as well that's the one we're
going to secure the isolation process on often on AM2 and AM2S rigs there is a remote switch
to isolate the distribution board you're working on and this is the position where we will lock it
off and put our sign entering the distribution in order to prove the circuit is dead so let's
lock off our isolator here before entering this electrical enclosure remember we should
have been looking for signs of things going off so as well as turning off individual circuit
breakers we should have been noticing maybe the light sockets machines etc going off so
when we do enter the electrical enclosure we are considering it to be isolated but working
in a manner that suggests if it was live that we're still working safely especially when we're
thinking about metallic enclosures being removed so case there will need to be taken when removing
the covers but we view in a position where we we think it's been isolated safely but we're
going through that process to prove it in the next few stages so as we have a remote means of
isolation for our distribution board this is the point in which we're going to secure the
isolation I believe something very similar on AM2 and AM2S padlock key and sign I'm not going
to use the master lock this time so I'm just going to position that through there like so
take my sign position it like so and lock it off Super Duper important that you keep the key do
not place it on the top put it into your pocket if you leave it behind where the assess if you
get hold of it you will fail either AM2 or AM2S or keep the key so I'm now in a position where
I can remove the front of this distribution board I believe I've isolated correctly I'm
still going in with care and caution ok I'm going to remove the four screws in this case I can take
the door off this stall so I'm going to take the door off to make it easier I'm going to
remove different four screws and then I'm in there and I'll be looking at then proving unit voltage
indicator in the process in order to confirm the bottom of this main switch has been isolated
prove that this distribution board has been isolated in the next part of the video so the
minute we've got the guards in place so I cannot see the incoming supply cables termination points
so I'm going to have to access this area here and it says danger voltage we're hoping that
we've isolated it remotely we know the main switch off but care needs to be taken when entering this
enclosure so when we're going in here again be very careful insulated screwdrivers etc so we're
going to take off the side panels and then we're going to remove this front cowling next so before
we start the safe isolation process we must prove our voltage indicator on a known supply I'm going
to use a proving unit so we're going to probe in like so so into one termination and then to the
other of it and hopefully we can see that the voltage shoots up all our lights illuminate and
we go of the scale off the limit so we've proved our voltage indicator is ready to start the safe
isolation procedure before you tell me how messy is and use of tie wraps and what a disaster this
looks like this is a legacy panel it's been wired by outside contractors etc and we're using it to
prove a point for the safe isolation I understand there's also a little plastic cap missing there
it's not essential but it is missing there we loads of things to be able to pick out for me I'd
appreciate if you don't in the comments because this is all about the isolation procedure the caps
on the bottom here are still in place and I can't touch those live parts I can't touch them actually
with the caps down but that they're in place and we need to move those out of the way before I
start the safe isolation procedure just pull those down okay depending on what documentation you're
reading it depends on which order these ten tests are carried out if you look on NET services at
their documentation about safe isolation they talk about doing it first of all between two of the
lines so effectively starting out at potentially four hundred volt test I don't carry mine out in
that way I'll do it in a slightly different way and some of your spoke to with Sparky Ninja as
well I don't like the fact that if it was alive that one side probe on to one of the the lines
the other tips obviously going to go live and therefore potentially dangerous so I like to do
in slightly different order have a conversation we were AM2 or AM2S inspector and just confirmed
to them if you do the 10 tests in the order that you're comfortable with will you be acceptable or
would he like you to do it in a certain position certain order so I'm going to start off by doing
what would be a 230 volt test if it was live we're presuming it isn't because we've safely isolated
it so I'm going to test between the neutral and line conductor I'm gonna probe on in the safest
possible order so I've gone the least dangerous conductor first so go into the neutral and then
I go on to the line conductor no volts at all I come off the line conductor I'm going to go
to the next line so I'm going to leave it on the neutral this time I'm not going to take it off so
go to the next one and L2 no volts come off and go to L3 no volts come off and it will come off
my neutral conductor so I've done that and what's the safest possible manner by going on the neutral
first I've made this tip live if we're gone on L1 first in the neutral your tip becomes live if the
circuit was energized that's the first three stages L1 L2 and L3 tested to neutral in my
sequence next on the test between the neutral and the protective conductor this is a TN-C-S earthing
arrangement so you'll get a continuity beep we understand that from classroom chat about how the
neutral and earth are connected together again I need to on the safest order out the neutral
and the protective conductor the protective conductor is the safest terminal so I'm gonna
probe onto that one and then on to the neutral you'll hear a beep because that's a continuity
not a voltage reading there's zero volts there and then I come off the neutral first and then
off my protective conductor that's stage four I'm now going to test between individual lines to the
protective conductor so we're at stage five on the testing sequence I'm going to probe on to my
protective conductor first and then I'm going to do L1 L2 and L3 very similar process what we did
with the the neutrals so onto the protective conductor and least dangerous one first then
onto the line conductor L1 no volts off the line L2 no volts L3 no volts of L3 off the protective
conductor so we're now at a stage where we've only got our test between our line conductors
we're presuming because of the tests were carried out so far it's actually isolated so at this stage
when we probe in between two conductors which we now expect to be dead and gone the issues will
living the tips up so we're into the final stages where we go between L1 and we're going to go into
L2 going to come off L2 and going to L3 and then I'm going to come off L1 and going to L2 all of
those had 0 volts okay so it doesn't matter which order we come off that completes the ten stages of
testing the three phase isolation of a in this case distribution board I hope this video helps
you for both AM2 and AM2S as well as working as a contracting electrician so before we can start
confirming that absolutely the safe isolation procedure has been completed we must prove that
our instrument hasn't failed in the process so we need to prove this before we suggest to our
AM2 instructor AM2S instructor that we are ready to start work so probe back into our proven unit
then always tricky on camera we've proved our voltage indicator is working correctly so at
this stage we can go back to the panel so just to confirm to reconfirm we tested between L1 and
neutral stage 1 stage 2 and stage 3 both the L1 L2 and L3 to neutral stage 4 between protective
conductor in neutral stage 5 6 & 7 was L1 L2 and L3 and protective conductor than we do
to L1 L2 L1 L3 L2 L3 in order to complete the 10 stages of testing for safe isolation you're
now ready to work within this distribute on board I hope this video there's been some help