- Hello and welcome to this Q&A video.
My name is Joe.
And today, I'm gonna be answering the question,
"Can basic insulation be left exposed?"
Now, this question came about
when Gary and Gordon tested the WAGO IPX8 range of Gelboxes.
And they showed in their video,
the termination stood up
to be submersed in a bucket of water.
In a later video, Joe tested the boxes again,
but this was to the required rate for IPX8
and 1 meter of water.
In both videos,
we saw how the WAGO Gelbox was placed inside an enclosure
and that although the connections were IPX8,
the full termination was not,
and it had to be enclosed in a box for basic protection.
Now, lots of you got onto us asking
why we had to put those Gelboxes within an enclosure,
because, well, the terminations were
more than adequately protected,
so much so they withstood a full 1 meter submersion.
Well, the reason is because we must ensure
cable terminations and generally any wiring systems,
which could be touched by persons or livestock,
must maintain basic protection and fault protection.
But what are they?
Well, in BS 7671, it says
that basic protection is protection against electric shock
under fault-free conditions.
So that's just when everything is working as it should,
which is how we want it.
But as we know, things don't always go to plan.
And as electricians, we have to make sure
we provide good enough protection
throughout the installation.
This means we have to choose
the most suitable protective measure for our installation.
Or it could be that there's more than one
depending on the installation itself.
Now, there are four protective measures
that we use most frequently.
They are automatic disconnection of supply,
double or reinforced insulation,
electrical separation,
and extra low voltage provided by SELV or PELV.
Now, each one of these has its own requirements
for basic protection under fault-free conditions.
And what's really important to remember
is that depending on what protective measure we use
will depend on the basic protection that we need to provide.
But we also need to provide protection
if a fault was to occur as well.
And that's the part we call,
well, you've guessed it, fault protection.
Now, BS 7671 says that fault protection
is protection against electric shock
under single fault conditions.
So how does this fit in with our WAGO Gelboxes?
Well, if you installed the Gelbox enclosure
with single insulation poking outta the box,
then the termination would not have met the requirements
for basic and fault protection for double insulation.
And we can have a look at that regulation now.
Regulation 412.1.1 says
that double or reinforced insulation is a protective measure
in which basic protection is provided
by the basic insulation
and fault protection is provided
by supplementary insulation.
Or basic and fault protection is provided
by reinforced insulation
between live parts and accessible parts.
So, the basic insulation is a layer of insulation
and the fault protection is that secondary layer.
So if a cable or termination maintains double insulation
throughout its run,
it is complying with BS 7671
and it doesn't need to be in any additional containment
as long as it doesn't need mechanical protection.
But that would depend on its location.
Now, I do get asked about meter tails.
I mention this because as I've been on lots of jobs
where the previous electrician has stripped
the outer insulation back to expose the basic installation
for identification purposes,
and normally where cables enter like a meter box
or a service box or a Henley block.
Now this would not satisfy BS 7671
as the tails at that point would've been reduced
to the basic installation only.
If, however, it was contained within an enclosure
like the top of the main switch,
then that would be okay.
Although sleeving does do just as good a job.
It's also very common as well to find ceiling pendants
where the basic protection of the flex
is poking out of the pendant or ceiling row.
So, something to watch out for when you're doing your EICRs.
So there we have it.
If you found this video interesting,
then be sure to check out the vast array of videos
we have at efixx.co.uk.
But, until next time, TTFN, ta-ta for now.