Gary Hayers - GSH Electrical & Joe Robinson Training
so with EV being such a massive topic in the electrical industry what have you brought me to this
electrical installation job well this property's just have an EV charge point fitted but we're particularly
interested in what's happened at the mains end of this installation to see how they've accommodated
this EV charge point should we crack open the garage or never look let's do it so he brought me
inside now Gary this nice cosy garage here and we're having a look at the mains end of this
installation so we've got to consume units there what's going on with that original Hager consumer
unit on the right there okay this is the household consumer unit that was originally in place we look
like we're on clover statement that Joe always loves because we've got the non RCD side with two
spare ways and the RCD side with one spare way so we've got a couple of choices I'm gonna can
engineering judgment now whether we're going to come out of the RCD side on an on our CD side any
issues if I come off the RCD side Joe what we need to ask Gary is what type of our CD is that there's
not automatically a problem with coming off the our RCD but we do need to know what type is so is
there any indication on there of what type yeah if I look very carefully here I can see a sine wave
indicating that this is an Type AC RCD and we know it's a hot topic in the electrical industry about
where you've got potential DC leaking in a circuit and it can confuse AC type of our CDs so straight
away I'm thinking maybe it wouldn't be a good idea to come off from this side another reason
one I won't need to come off this side have our CD protection for the cable is two things there's
our CD protection already within the actual IV charging point and also the cable and how it's
been installed the cable for this installation is using PVC PVC twin and CPC and clipped direct to
the fabric of the building therefore doesn't need our RCD protect him if I was to our RCD protect you
of both ends so one within the EV charging inside the consumer unit I would lack selectivity Joe so is it
a straight case of coming off the non RCD side once again that is certainly an option however
there are one or two challenges with coming off the main switch side in this case so talk us
through those Gary yeah what I've now got to do is make sure I get exactly the same kind Hager breaker
I've got installed here if I find one that fits but isn't the same manufacturer it won't have
been type tested to be installed within this and can cause some issues with thermal constraints and
underperform or cause issues through the breaker that sits next to so again that's not a good idea
I understand why they've installed another consume unit it's probably easier to install
a consuming and it is perhaps to hunt down the appropriate break up thirty-two amps and then the
appropriate type for this Hager board so that's one of the considerations to make so we've gone
with a new board based on the fact that we don't want to confuse an AC RCD potentially with DC that
could lead back we've also got RCD technology in the EV charging point we've chosen not to come out
for non RCD side the electrician here because obviously, we've got to get hold of one of these
breakers so let's have a look in the new board and see what other decisions have been made in there
okay so we can see a nice shiny new consume unit there guys looks like it's metallic construction
so obviously to conform to the latest standards so what are we looking at inside this new come to
Munich okay so the engineering decision of the electrician was to install a new consumer unit
and they've also made another decision no doubt a conversation with the customer they've also
introduced surge protection we know in domestic dwellings single occupancy domestic dwellings
that a surge protection isn't a requirement but I've obviously had a conversation and decided it
would be worthwhile for me again you've probably got a forty thousand pound electric car full of
electronic components surge protection device would be a good plan for me we've then got two
breakers we can take the cover off in a minute I have a look in there one of the breakers I would
think is feeding the surge device on one of them is feeding the actual EV charging point now the
the cable going out as discussed before was in PVC PVC twin and CPC cable and it's clipped direct
to the surface so there's no RCD required here and again you can get round that if you had say steel
war armored cable feeding out there again because you got a metallica sheathing it wouldn't need an
RCD protection so let's knock these off there's no loading circuit so the car isn't plugged in or
challenges so I'm going to turn these offload so not these off and then the main switch and let's
go and see what's going on in here with the cover off the world of pain notice the stickers are
missing on the front there still to be in the store so I take that the formal commissioning
hasn't been done and hand over paperwork cover off like so and there we go so we've got 25 millimeter
squared metering tails coming in and in a minute job's been explained to us what's happened at the
mains end in order to add another set housing because it was obviously one for the original
consumer unit and yes we've got a 32 amp breaker here Joe feeding our SPD and we got a 32 amp
breaker feeding our EV charging point if there's been any special consideration about the conduct
to length for the surge protection device in there Gary yeah good question Joe it's always got to
be kept super short so the protective conductor coming out at the bottom goes directly into the
earth bar and the conductor coming across here just and loop straight across remembering it's
a half a metre roll of a combined length and we can clearly see that we've kept it under it often
we know we like to dress and drape round tables within consume units and for the surge device
that is not a good idea I think it's time to take me outside Joe and show me what's happening
at the mains end where the metering equipment is let's go popped open the meter cupboard and there
seems to be a lot going on in there Joe absolutely Gary's escaped behind the camera he's all bundled
up nice and warm while I'm out in the cold as always but what's happened inside here you can
see that there's been a few modifications taking place inside the meter cutout box here so I think
we need to just bring the camera in a little bit closer so we can have a look at some of these fine
details so there's an awful lot going on in there so looking at it from start to finish the first thing we've got is the mains cable coming in and the experienced
observer will be able to immediately tell that this is a TNCS system with a PME that the regional
electricity company have provided here that comes into our service head and into our cutout
so there's our main fuse for the installation and coming out at the top of our service head we've
got our meter tails going into the regional electricity company's side of the meter into
that side there and you can see that this is all sealed up as appropriately underneath this cover
you've got the main 100 amp isolator switch which obviously was used when these were being modified
because normally you'd expect to see the tails going from the meter directly to the consume unit
however because this installation has had a new consume unit installed the tails have been split
at this point and the existing tails were wired into the existing consume unit and a new set of
tails were taken out to the new consume unit so if we just kind of trace these through you can
see this is the line meter tail coming into the bottom of the meter and the neutral coming to the
bottom on the meter and then we've got our line mate sale coming out of the meter and into this
connector block so you can see there that from there that's been mounted onto this back plate
here and the is regional meter tail back to the first consume unit has been reinstated there and
the new meter tail going out to the new consume unit has been put in place there we've then done
a very similar thing with the neutral tails you can see that that's come out the bottom of the
meter into this new connector block that's been mounted on the surface here there's the original
neutral conductor going up to the original consume unit and there's the new neutral conductor go into
the new consume unit we've then got a similar situation for our earthing conductors so this
one comes from the cutout down here from the service head into this connector block and
then out of there goes the original earthing conductor up to the consumer unit and here is the
new earthing conductor go into the new consumer unit now it's good to see that the Installer
has matched all of the existing meter tail sizes which are all the correct meter tale sizes for
what should have been installed so the line and neutral conductors these are all 25 ml squared and
the earthing conductor is a 16 mil squared now one more thing that you might not always expect to see
on the installation you might be looking at mister wondering what this is the evey charge point that
has been installed on this property actually uses a current transformer to monitor how much
current is either flowing down the line into the installation or how much electricity is actually
being exported from the installation if there's any things like solar panels or wind turbines been
installed on this property it's all in all its FET so this is actually a very very thorough and
competent electrical installation that's taken place inside this cutout box so we can see in
this installation it wasn't a simple case of just taking a cable from the consumer unit to the end
point use there was a lot more involved absolutely the installers made some informed choice is such
as installing a new consumer unit to introduce surge protection and also to keep everything
away from that AC RCD we don't want that being blinded by the DC that this would be putting back
into the system and also avoiding the issues with selectivity as well installing the cable in such
a way that it didn't require RCD protection knowing that RCD protection is inside the
e V charge point there is a really really smart label if you don't see anymore videos that we've
done on EV we've actually done one on how to check any EV charging point so we've gone through
stage by stage on how to test one of these devices that might be a video that's worth checking out