what are the chances it's yet another glorious sunny day here in the yorkshire dales and we're
back on one of our favorite topics today it's ev charging we're gonna answer a question we
get asked a lot on the channel and it's related to garages and outbuildings and can you add an
ev charge point to the supply that already feeds a garage. of course, the garage or parking area is the
natural choice for the location of an ev charger and that's what this homeowner wants to do here
the garage is detached from the house but it does have an electricity supply but the garage
was built some time ago so possibly they weren't thinking about the future and ev cars coming along
so if you're thinking about any development stick around because i've got a top tip for you that
you may wish to consider if you're planning any building work i've popped inside the garage to
have a look at the electrical supply and behind us there's a small consume unit that's typical that
you find in most garages or detached buildings it's feeding sockets and some lights so this place
could form a useful retreat if you want to escape from the relatives over those busy holiday periods
but is it enough to feed an ev charger well there is a few options however let's look at
the distribution board itself the first problem is there is no spare capacity to add a new circuit
for an ev charger now that could easily be upgraded and replaced however the next problem
and possibly the most major one we want to think about is is there the capability in that cable
to feed the garage and what is a new seven kilowatt load that you'd ideally want to
add if you want the maximum capacity from an ev charger the main consumer unit and the circuit
that feeds the garage is in this cupboard here and that gives us a clue as to how much power is
available to the garage if we look at the circuit breaker for the garage we can see it's rated at
20 amps so that is significantly short of the 32 amps you would need if you wanted to install a
seven kilowatt charger however there is a solution to that that we'll discuss a little bit later on
while we're looking inside there the circuits will see that the rcd that feeds the property
is a type a which is good news because it means if you had to add an additional circuit in there and
there is space for it the rcd itself is suitable for an electric vehicle charge point however the
one at the garage end isn't because that's a type ac and that would need to be upgraded if
the cable itself isn't suitable to feed the garage and we want to run a new cable back here however
there could be a few challenges because this space is fully decorated and we may not necessarily want
to bring in a new cable and have to do some major alterations to the wall so unfortunately the power
supply feeding this garage isn't large enough to accommodate a full seven kilowatt electric
vehicle charger however that doesn't rule out being able to fit a charger it's just that
we'd have to de-rate it to not exceed the power supply of 20 amps that's coming into the garage
and therefore we wouldn't be able to charge the car at the full speed of a seven kilowatt charger
so let's also explore another scenario where the cable itself and the circuit breaker are rated
at 32 amps to supply the garage we also need to think about what other appliances are using power
in the garage itself and we can see here we can see that emergency beer fridge behind us
and we can also see what's known as the bubbler drop a comment below if you know what a bubbler is
but there also may be scenarios where you have tumble dryers and other appliances in
the garage and they will obviously be using some of that power and again that doesn't
restrict us having a full powered ev charger because depending on the brand and the make of
charger you choose there are options in some ev charges that allow them to current share
with other appliances that are in the garage so let's think of the scenario you're charging at
seven kilowatts and somebody switches the tumble dryer on or another appliance in the garage
you would have a current transformer fitted to the circuit feeding the garage that would sense that
something else is drawing power and automatically turn down the ev charger to a lower current draw
during the time where that appliance is using power so that's a neat solution uh a little bit
tricky obviously if you then also need to use the current transformer to monitor the
incoming supply to the property uh but don't forget there are also some of the charges that
enable us to have one or two current transformers to deal with that situation
so before we leave the garage let's just consider one more scenario that could get us out of jail
what if the cable behind us was underrated at the circuit breaker so in other words
the cable is thick enough to carry more current so we may be looking for something or a six or
ten millimeter and the electrician has underrated it with a smaller sized circuit breaker that could
be a great situation however some caution about that when the electrician originally installed
this cable it will have considered lots of other factors including the voltage drop between
the distribution board and the garage and possibly some other thermal constraints and the cable has
been derated for a reason so don't assume because you've got a thick cable you can just increase the
circuit breaker so we've spoken a lot about power supplies to garage but let's not forget that other
problem we have when it comes to ev charging the internet connection because all chargers
have to be smart and obviously the easiest way of getting that connection is to use wi-fi or some
other ethernet based connection so you can enable things like smart charging and smart tariffs so
if the garage is a long way from the house we certainly know that wi-fi could be a problem
so if you're gonna have to pull into the cable it may be worth pulling in an ethernet cable as well
to feed either direct to the charger itself or put a wireless access point in there the advantage be
you can also have wi-fi in the garden so the solution for this installation is it's going
to need a new cable pulling into the garage to feed the ev charge point and that's a
considerable amount of work because it is a detached building and there's also existing paving
down there but fear not ross from rs electrics is already beavering away digging that trench and
facilitating that new cable also going to put an external distribution board near the meter
enclosure to feed the garage itself which brings me that top tip i promised at the start of the
video if you are planning to build a garage or have any other major works done on your house
think about that future you may not believe that evs are with us you may be holding out with petrol
and diesel for as long as possible but at some point they are coming and think about that cable
if you're building a garage put in a bigger cable to facilitate a future ev charge point now as we
turn back to some advice once given by rich heppel the smart home expert the most expensive cable
is the one you don't run and that can certainly be the case if you find you're having to pull
in a cable to a detached building that could have easily incorporated
during the build phase or even a simple duct to run that on this property the owner is also
looking at upgrading to have some solar put in the garage and some battery storage which is another
great option that we'll be looking at on the channel soon check out our other ev charging
videos we've got everything in there including that other installation stopper the looped supply
i will leave a link in the description for that or in the eye above my head
and we look forward to getting your top tips on detached buildings and ev charge points in general