so then Joe today we're going to look at some not all of the requirements for GS38 yes
this is embedded in the early health and safety unit that we deliver at level one level two and in
the apprenticeship framework absolutely however we go on later in the course to look at using
leads that can form and instruments that conform to GS38 when we're doing them
so when we're looking at our inspection and testing units if you're on an apprenticeship
and also your fault finding units because for both of those units you will be required to carry out
safe isolation as part of an assessment so knowing the requirements of GS38 that guidance note
published by the HSE is really really important whatever part of the course you're currently on
so then Joe we can see how GS38 is going to be really important to us from almost the moment
we arrive at college to the point that we exit to do say AM2 or AM2S absolutely so where can i find
GS38 it's very simple it's a free downloadable pdf if you just go to your browser type in GS38
pdf and generally speaking it's the top link because if you click on that it will take
you straight to the pdf document published by the health and safety executive and you'll be
able to scroll through it's a document that's nine pages long and today we're going to focus on which
key bits of information Gaz so i always say to my learners and they will be downloaded in that first
few weeks we're looking for the pictures which i think are on pages four five and six yeah that's
the key ones yeah so we're going to need to read the whole document but focus on the bits that come
out in pages four five and six and we're looking at the requirements for both the test leads
and the test probes yeah themselves so there'll be some key information in there and that can
be asked of very basic health and safety exams as well as AM2 and AM2S so in front of us Joe
we've got a couple of different manufacturers of voltage indicators as well as proving units and
that's really key as well that we can actually pre-check our voltage indicator before we use it
and after we have used it okay so that's these things here so that's a proven unit here
and we've got a proven unit over here this one's a little bit more tricky because it's magnetic
and we've got metal tables you want to have something there generally when you put it down
so so let's have a look at the actual voltage indicators themselves we'll concentrate on the
one made by Megger yeah okay so we're gonna have a look at that one however we have got another
one over here exactly the same requirements applied yeah so we've got a few things that
we need to think about when we first look at this we've got uh first of all we've got these
extremely long tips on show here so these very very long tips what's the issue with perhaps using
those straight onto a potentially live terminal oh so once the tip itself becomes live the remaining
part of the exposed tip will also become live and there is a chance that we could touch those
tips or perhaps even move that tip onto a side of something that isn't meant to be live maybe that's
earth causing that a short circuit and therefore disconnect the circuit massive explosion oh all
kinds of issues we don't want any of those so to get around that what does GS38 recommend
for our probe tips there so as we look through the document and our learners will and we're not going
to give you all the information because we're going to use some of that in the classroom so
you're going to need to read those pages however it's key that the tip length doesn't exceed
four millimetres and i can clearly see here that that's way over four millimetres
yeah another couple of options that are available again you'll find that in GS38 but here we're
going to comply with the four mil maximum and the two mil recommended very simply by putting
on these caps that have been provided with the piece of equipment and when we put that on there
and screw that on you can see that actually we end up with only just the very very tip
of that probe showing and therefore we now know that if we were to put that onto a live terminal
we've only got a very very small amount of conductive material
sticking out at the end there and that is very very safe so as i look down at that i
can clearly see that isn't at the maximum yep four millimetres and it's probably under the preferred
two so we've got a very small tip exposure there so when we probe on we haven't got any issues
that we discussed pretty absolutely and if you watch some of our other videos on safe isolation
you'll see one or two recommendations about making sure you've made a good contact
with the potentially live part and not accidentally missed it and also there's an order
in which we should prove on depending on whether we're looking at maybe a line a neutral our
protective conductor absolutely so that's in some of our other video presentations that we've done
so joe that's key for us and our learners will be asked many questions on this so maximum four
yep preferably two there is another one though so as you read through the document you'll see
another one yeah or sprung loaded all right so as we look at these here joe on this different make
we can't see any tip at all nope so there's no exposed metal on the end there so if i push it
against the actual surface itself it'll expose the tip that's obviously way too much but if i
can do the following you can hear the contact very good yeah so that is actually with contact and we
can see no part of exposed metal work yeah okay so we've got a couple of key bits there maximum four
yeah preferably two yep perhaps preferably sprung loaded or an alternative being sprung loaded and
just to make the point it would not be acceptable to try and probe onto a terminal by pulling that
back because another part of GS38 also speaks about having finger guards and barriers in place
on your pieces of equipment so you should not have your fingers anywhere near that tip pulling that
back to access a live terminal you simply as you quite rightly demonstrated push that on and it
will make contact and your fingers remain behind that safety barrier so you can't accidentally slip
and touch a live part yeah it's really good so there's another point then as you read through the
document it will say talk about guards or finger barriers it'll also talk about shaping of probes
so again to prevent slippage that we've got a shaped probe so if we look at this one again
we've got a slightly finger guard here stopping us falling forward okay and we've got one here again
to stop us falling forward and it's so we've got an ergonomically good grip so we don't fall into a
live electrical enclosure yeah and again you can see you've got this slightly rubberized grip as
well on this uh handheld probe here to make sure that you don't slip into potentially life terminal
so we can already see Joe that our learners are going to have to pick up a lot of information
just a short space of time in with us a couple of weeks and we're going to be picking these
questions at them as we look at both of these so we go back to the mega one we've got a lead okay
and how would we describe the material that makes the lead between our two probes it's certainly a
very durable material isn't it a good word durable it's going to make sure that that doesn't wear out
become cracked damaged or anything like that but of course it is your responsibility not to rely
on that being durable you do need to inspect this before every use to make sure that you've
not got any exposed parts sticking out there also adequate length and we can now see but especially
by the level one learners we're adding some some words in that aren't familiar necessarily in usual
talk are we talking about durable adequate length okay so again adequate length so we
don't want it really short so we can hardly get it into the terminals or moving between them
and we don't want it so with the lead so long that we're treading on it or it becomes an issue
trip hazard so again of adequate length made of a durable material we'll also go on and talk about
other ways in which we can improve safe isolation and whether the leads have to be coloured and
whether the leads themselves have to incorporate a fuse and a current limiting resistor but remember
this video is also linking to learning in our classroom and the document that you've downloaded
so then joe so we've done perhaps all the pre-inspections we've confirmed our voltage
indicator conforms to gs38 the document which we've read we're starting to understand that
document but before i go out and use this to prove and in our case a circuit is dead because
we're not proving circuits are live at this stage especially early on on the health and safety units
so we're not doing say a recheck supply polarity test can i just walk out into the electrical
installation having done a visual inspection of my tester maybe even made the lights flash on it
and then use it to prove a circuit is dead absolutely not what we need to make sure is
that we make sure that the kit is actually working it needs to be doing its job okay
and so in order to do that there's a couple of ways you can do it you can use a known source
i prefer much prefer using a proving unit i think there's issues with using a known source
but i much prefer using a proving unit such as the one we've got here this is designed to work
in tandem with this it is and it tests the full range of this piece of equipment making sure
it's working properly if i'll just lift that up maybe we can just try and see if we can show this
camera so if i put these probes in here into the two holes and just press down
you can see there that we get all the lights on both the voltage indicator and also on the
proving unit okay so we know that both are working correctly and then we know that this is safe to
check for live on the circuit we're trying to isolate and we're not looking just to hear that
noise no okay we're actually looking at the screen seeing it fully illuminate et cetera and likewise
on the actual proving unit itself and then we're probably happy to go out into the installation
work safely okay and that's something that we've done at college under controlled conditions
very much so and of course once you've been out and you've proved that your circuit is dead Gary
can you then start work and just forget about this or what do we need to do next there's a load
of other requirements we're going to talk about this actually in the classroom about securing the
isolation okay process but then we've got to come back haven't we we've proved the circuit's dead
yeah but we've got a final check again we need to go back to the proving unit there is a possibility
that your voltage indicator could have stopped working in between testing and checking for live
it might have broken and you go oh that's great it's dead but actually the circuit's
live and this is broken okay so you kind of do always call it a sandwich a testing sandwich
you then plug the probes in and make sure that it's still working so you know if you get nothing
when you connect onto your circuit you know by coming back and testing that you know that that
circuit is dead so there's a lot of information for our learners to take in and we haven't give
the all the information out because we want people to be working through the document which is GS38
so let's just summarize a few of the key points maximum tip is four millimetres long
preferably two yep and then there's another preferably joe yeah we also like it to be
spring-loaded as well as another option yeah another option to be spring-loaded
we know that um the leads themselves need to be made of a material and we use the
word durable yeah to make sure that it doesn't get easily damaged in use of adequate length
and then there's some processes to go through we've got to use this here which is called a
proving unit yep so we're going to prove our tester before using it we're going to test
the circuit is live yep are we going to test it's live we're going to test that it's dead
we're going to prove a circuit is dead yeah and we might first of all see that the circuit is
dead by physically seeing things go off yeah so that'll be something that we'll talk about
actually in the classroom in the workshop and when we've proved it's dead what do we do then we then
go back and we re-test our voltage indicator to make sure it's still working after blocking off
all of the relevant isolators circuit breakers or whatever it is that we're isolating with
so this video introduces GS38 it introduces the voltage indicator in the proving unit and we're
going to go on and look at locking off and making a circuit dead and proving it is dead as well
all of those things will come in the classroom there are some other videos on GSH that
also improves safe isolation and recheck supply polarity so i think we're ready we're there
we hope this video has been some help