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- Here at eFIXX, we love an LED,
and now, we've got one inside our consumer unit.
We're gonna be looking at arc fault detection devices.
In North America, they've been using
arc fault detection for more than 20 years,
and we're gonna look at, in this presentation,
the Single Module Arc Fault Detection Device by Wylex.
So let's see what all the fuss is about.
So let's first consider where we've come from
and where we're going to.
So this consumer unit here is made of wood,
a combustible material.
It's also probably coated in a lacquer
that is even more combustible
than the consumer unit itself.
It has no tool or key in order to enter it,
and when I open up the enclosure,
we have no protective bar,
so there's no CPC bar,
there's no means of isolation
built within the consumer unit.
As I pull out an overcurrent protection device,
it has an asbestos pad and a piece of copper wire,
which is smaller than the conductor in circuit,
and when there's a fault, we hope this wire melts
before the one in circuit.
That's where we were,
and this is where we're going to.
So we'll all agree that this consumer unit
wouldn't offer the level of protection
that we expect in a modern installation.
So this single module arc fault detection device
incorporates the technology behind a circuit breaker,
also the technology behind the RCBO,
so earth leakage protection,
but also protection from arcs,
both series and parallel arcs.
Now, we can think of a parallel arc
between two conductors and we can envisage that one.
It's the series arc.
Well, is it two conductors in a cable
that have broken and are now very close
to each other, an arc in between them?
It could be but I think the easier way
to look at a serial arc is a conductor
inside a termination that isn't tight,
and actually bouncing between the actual connection,
creating an arc, therefore, a serial arc.
And we can argue over time,
with the introduction of things
like torque screwdrivers, et cetera,
that we should have overcome
perhaps the lack of tightness
or over-tightness of conductors
that could lead to serial arcs.
However, we know in the real world,
that's not always the case,
and this device will protect against that.
So let's take a closer look at this
by fitting it in the consumer unit behind me.
We're gonna fit the B32 30-milliamp AFDD RCBO.
If I drop down the mechanism,
you can see it's an A type.
There's some other nice features about it,
they also make them in ampere ratings
of 6, 10, 13, 16, 20, 25, 32, and 40 amps.
It also has the no miss bus bar technology
built into it, so as I tighten this up,
you can't miss the actual connections below here,
as well as the quick release mechanism.
So in other words, we don't need
to take this bar out in order to fit our breaker.
We're used to this section here
clipping onto our DIN rail at the back,
so all we do is pull this clip forward,
and click it into position,
so that's held forward, if I just drop it off.
So you can pull it forward,
you can now see that that mechanism has dropped down,
so allowing me to fit it straight
onto the bar without removing it.
So move the conductors out of the way, like so,
and let's just drop that into position.
Push the clip back and now,
we can just tighten up our screws here,
and insert our conductors as well as our neutral fly lead.
So, I pop my conductors into my AFDD.
I've confirmed with a torque screwdriver
the torque settings of both the conductors,
the connection to the bus bar as well as the neutral bar,
just to prove this is a flex here,
this is actually on a plug top,
this is a demo board for video purposes only.
Next, let's talk about the actual
arc fault detection device itself.
It will not operate when there's a spark.
So when you open and close a switch,
dim a circuit, you can create sparks but not arcs,
and this device is not designed
to detect those and operate.
It will operate under arc fault conditions,
either serial or parallel.
Parallel between conductors, maybe chewed by a rodent,
or series ones, as we discussed previously,
about maybe in a loose termination creating that arc.
It needs to be of a certain duration,
at a certain waveform in order for it to operate,
very intelligent piece of kit.
What I'm gonna do next is I'm gonna plug it in over there,
and we're gonna have a look at the LED here,
and then, discuss the other patterns the LED can be in,
in order to tell you what type of fault
you've actually had in your installation.
So before this video is over,
I wanna show you this bit of kit here as well.
This is the NM range of Wylex consumer units,
and this bit of kit here makes electrician's
life easier, and we like that on eFIXX,
so stay on for that.
So let's first have a look at an unenergized AFDD.
So if we just push it into that position
with the circuits all off, so you've lost the power supply,
you can see here that the window itself has no light on.
So in this case, no supply, logical sense.
Let's turn it back off,
and let's energize it.
And now, we turn on the AFDD,
and you've got a red LED light showing,
so the circuit is healthy and correct
with a red LED light in this window here,
but can have other colors to denote other issues.
So let's go through some of those.
If this window here was not red
but a single pulsating yellow LED,
that would be for a series or parallel arc detected.
So if it was a double pulsating yellow LED light,
it would be for overvoltage.
So it would be a voltage greater
than 285 volts AC detected.
A triple pulsating flashing yellow LED light
is a residual current detected,
so the RCBO element of the devices operate it.
If the light is going red, then yellow,
red, then yellow, this means that
there is a self-test failure.
These devices self test themselves every 15 hours.
The requirement is that they should test themselves
every 24 but Wylex deemed it to test it
every 15 is better, meaning it's tested
throughout the day at different parameters within circuits.
If that test fails, this will flash red,
then yellow, red then yellow,
and you're required to call an electrical engineer in.
The electronics in here have failed
and it needs replacing.
In order to carry out the functional test,
it's exactly the same as you would do on a standard RCBO
by pressing the test button under here
but this time obviously, it's illuminated.
You simply press the test button there,
that will test both the RCBO
and AFDD elements of the actual device itself.
Let's imagine we wanted to have
a fully isolated board or just one circuit,
comes back to this little bit here
that I talked about earlier on.
So we've got all the board de-energized.
Take off this flap like so,
make sure you keep that.
Take this piece here, this handy little piece here,
and it's gonna come under the back part
of the lip itself of the lid.
So I just lift it up and just slide it under there, like so.
Align it back up, and now,
I take my padlock and sign.
So I take my sign, put my padlock,
and we go through there like that,
and drop it into the hook.
I'm going to keep the key in the pocket,
and now, I'll actually secure the isolation
of the entire consumer unit.
I really, really like that,
just one thing is just to keep hold of that.
You don't wanna be looking for that at some point.
So I've got my Metrel 3152 Multifunction Tester.
It leads me into the next great feature
of the AFDD, it's two pole.
So in other words, when I operate the mechanism,
it disconnects both line and neutral.
Therefore, when carrying out
your insulation resistance test
from the top of the device,
it means you won't pass that high voltage
back through the electronic components
within the device itself.
So we can see that this AFDD
will offer protection against serial and parallel arcs,
reducing the risk of fires.
It offers earth leakage protection
in the form of the RCBO that's built within it,
as well as short circuit and overcurrent protection
from the technology behind the circuit breaker.
Our friends over the pond
have had this type of technology
in their electrical installations for almost 20 years.
I'll be really interested in your comments
on whether the AFDD is where we're going next in the UK,
so please make sure you comment down below.
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