well gordon you've brought me down to
this Contactum and three-phase
distribution board and you said we're
going to talk about surge today
yeah a lot of people investing now in
surge protection for that sensitive
equipment you might have in a factory or
warehouse environment
but how many people actually check to
see if those surge protection devices
are functioning
as intended?  so what are you suggesting
that we're not going to the surge device
and looking to see if we see a green or
red window well i'm suggesting yeah
people don't look behind this hidden
door beyond this lovely mechanism
and peer through the window and notice
if that flag has turned from green
to red okay so what's the solution then
if we're not visually looking at these
surge arresters well we're going to find
out how to make an
indicator device that sits alongside the
panel to show you the status of the
surge protection device so you're
telling me this green lamp here
is equally indicating the fact that it's
in a green status there
yes exactly correct and if the surge
arrested life had gone and that window
in there had turned to red
you're telling me this is going to turn
to red well i'm hoping so
should we take you to the bench let's
have a look so can you talk me through
the processing
okay so on a lot of surge protection
devices on the back you'll see these
three connections there so these are
volt free contacts so there's no power
derived from the wires coming in from
the circuit
but you can use those normally open
normally closed
to trigger a device if the surge
protection device has failed
so normally you'd see the flag change
from green to red you would do
or if someone's removed the device
itself you'll see there's a little micro
switch behind there
which again will change those contacts
over okay so that also works for
tampering if somebody was to come along
and actually just take those out
it would obviously indicate as well that
they've been removed hopefully when we
get to the end of this we can simulate
the failure by removing the device okay
that makes sense
you are drawing in front of you as well
is that going to help explain the
connections we're going to need to make
on the rig behind us yeah so the circuit
i've designed here we're going to use
two
industrial indicators 22 millimeter
holes holding there i've actually
amazing how straight i got those holes
in there going i bet they didn't come
already pre-cut into the enclosure did
they that's a top tip
you can buy those enclosures pre-drilled
ready to take them normally you might
see the start and stop button in there
okay so
pick up this famous sketch okay um an ls
lousy okay brilliant sketch though yeah
so we're going to take the neutral
conductor straight out to the
indicators itself right common them up
on the back already there
using the blue in the flex and then i've
got the common from the line conductor
which is going to pick up in here we're
going to pick that we're going to rob
that from the supply to the
metering device that's in there and then
it's a case of taking the
normally open contact out to the fail
lamp which is the red one
and that will not be illuminated under
normal conditions that's it and then the
normally closed
when everything's healthy we're going to
take it out to the green lamp and the
green lamp will be permanently
illuminated under normal conditions
that's
it okay so we've put the assembly here
for our okay and failed indicators that
we saw on the bench we've passed our
conductors
in and we've now got to make our
connections for our permanent line and
neutral
we've already picked up a line conductor
here using a double ferrule
our cables coming down here through
these fuse sections then feed our meter
and we thought it was best to come off
this fuse section here so i've just got
to make the neutral connection here
but i've also got to join the neutral
that we're needing for our indicator so
we're going to join those together in a
double ferrule
if you haven't seen our video on
improving electrical connections using
ferrules i recommend you check that one
out
then what we've got to do is just follow
it through so a line that we've already
made comes through to here
and goes into our common connection and
then this side we've got a normally
closed connection which we've got to
make for
our green indicator and i normally open
on the other side
for our failed indicator so we're going
to make those off
as well so let's start off by doing this
double ferrule so i just need to strip
back these cables
like so i'm going to twist the
conductors together and just put a
double ferrule
on it so we take those
i'm just going to twist them up and
we're going to use a double ferrule
just improves that connection this makes
it a little bit more secure where we're
going into the actual
DIN rail itself take my ferrule crimping
tool
just bring that one up and then if i can
see what i'm doing
i'm just going to pop that into there
you can let my neutral up into there and
then it's just a matter of making two
final connections
so that one's in like so
and now we can just follow it through to
here
and i know that when that goes in here
my connection this side
is the normally closed and then we've
got the normally open
and we've cleverly indicated them green
one for our normally closed and red one
for our normally open need to take the
green one for unnormally closed to be
the first
of our terminals a slightly smaller
screwdriver in my hand
i can tighten those up and then we can
do the red one
in our second terminal for our normally
open
like so and then we just pop into the
bottom of the surge and then we should
be able to indicate
when that surge arrester's life is
expired so just pop that in under here
and we're ready to see what happens when
we energize that up i think then what we
can do is pull one of these out
that will effectively make it out to be
a fail and we should see the lamps
change
so powered up board we're under control
conditions we've got this panel removed
we've got it removed i'm a little bit
concerned going i've got a red failed
indicator on my side
good reason for that gary i've removed
one of the surge protection devices and
that's mimicking a device failed which
happened in
two ways either someone has removed the
device and not replaced it
or if the device had had so many hits
because of surges
it's the little red indicator appears
but actually when that happens a
mechanical mechanism inside moves
would move this little pin on the back
and trigger the micro switch in the same
way so that moves forward allowing it
actually to pull out as we're in this
position here so i'm hoping that when
you put that back in we close that
circuit and the green
lamp will illuminate the same gary
otherwise my diagram was wrong at the
start to put the
module back in the light's change we
like that okay
so there is there's one thing that i've
considered while we've been doing this
we could have taken the actual feed from
the breaker that fed the surge
and gone through and done our circuit
why would didn't we do that gordon okay
well
that if someone had switched off the
breaker then both lights would not be on
so then again you're relying on
somebody's spot that actually
there's no lights on okay so in this
case coming off a slightly different
circuit that was fused down that
we thought we'd use it means that even
if you turn off the breaker for the
surge we're actually still got a green
light indicated
yes that's it okay yeah so yeah
so that could be a potential problem but
i'm sure the viewers can sort that one
out
so we're always interested in your
comments okay are you currently fitting
surgery devices and how are you getting
on with doing that have you ever fitted
an indicator lamp
or siren to show that the fact that it's
failed
or in a healthy state would be
interested in your comments below and
we'll try and get back to as many as we
can
