in this video we're going to discuss what a fuse box or consumer unit does
and explain some reasons you may want to upgrade it
so let's first of all explain just what we're talking about here in every home there will be
somewhere a box full of devices that protect the electrical installation in the property this box
goes by many names you may know it as a fuse box or a trip switch box or a distribution board or a
consumer unit and that last one is probably the most technically accurate it's what the
electrician will most likely call it and it's what we'll be calling it for most of this video
so what does it do well a couple of things the local electricity supplier brings a
cable into your house now we could connect everything onto that one supply and feed
everything on one big long cable all around the property everything would work but this
isn't ideal because things like lights would need to be made as electrically robust as your oven
which is impractical and if one item tripped the circuit or blew a fuse
everything in the house would go off so that's the first purpose of the consumer unit it breaks the
electrical supply down into smaller circuits so things like lights sockets and individual items
like ovens and immersion heaters can all be kept separate and a fault on just one of these circuits
doesn't disconnect the entire house each smaller circuit needs to be protected though and that's
the other purpose of the consumer unit it contains devices that protect the circuits
to understand fully the benefits of upgrading your consumer unit let me just explain what we mean by
electrical protection first of all we need to stop too much electricity passing through the cables
because if too much electricity flows the cable gets too hot and this can start a fire or melt the
protective insulation leading to electricity leaking to places that we don't want it to
another thing we need to protect against is people getting shocked by electricity
we also need to give consideration to preventing surges in the electrical supply damaging equipment
in the home and also preventing arcs in damaged cables or degraded connections from starting
fires now over the years consumer units and the protective devices in them have changed
and developed to provide better protection to the electrical circuits to the property and to people
inside those properties so let's take a look at how this happened and as we do so see if you can
recognize your own consumer unit type along the way first of all we'll look at one of the oldest
types that you may find in your house now if your consumer unit looks like the one on the screen
that's probably better referred to as a fuse box because the protective devices inside here
are actually fuses now these work by having a thin piece of wire passing through them
and if too much electricity passes into the circuit then this wire gets hot and melts
which disconnects the outgoing circuit preventing the cable from overheating now for a long time
this was the accepted method of protecting electrical circuits but there are one or two
problems with it one example is that it's possible to replace the fuse wire in here with the wrong
size leaving the circuit in an unsafe condition they're also quite slow to react when faults occur
that you want disconnecting quickly and once they've blown replacing them and getting the
circuit back on is a bit of a faff another thing to bear in mind is that these fuses are not there
to protect people they protect the cables and equipment making up the electrical installation
and by extension the fabric of the property it's also possible that these fuses are mounted
in a box that is at least partly made of wood which is famously flammable and so not ideal
as part of an electrical accessory so while this type of fuse box does offer something
in the way of electrical protection it is far from ideal for protecting you and your property
so a more modern solution is to use the miniature circuit breaker or mcb now if your board looks
like this with a big main switch at one end and lots of these breakers then you've got slightly
better protection than the fuse box because these protect in the same way as fuses but are quicker
to react to big faults without overreacting if a circuit is slightly overloaded for a short period
of time other advantages are that they can't be easily replaced with the wrong size breaker by
an inexperienced person and they can be reset after a fault in the circuit has been fixed
however one thing they do not do is to protect people from electric shock they're designed to
protect the electrical installation from damage and properties from fire not people from harm
so in order to provide protection for people we need to introduce a new device called a residual
current device or rcd simply put this protective device looks out for electricity leaking to places
that it shouldn't like through a person and then it disconnects if it sees that happening
now it's not 100 effective it won't protect you against every single possible electric shock you
could get but it vastly reduces the risk of that happening now rcd technology used to be quite
expensive and so we used to install maybe one rcd protecting several circuits that required it
or indeed every circuit in the house so the rcd provided protection for people
and the individual mcbs gave protection for the circuits however that then led to a situation
where a fault on one circuit could disconnect several circuits now this could be a problem
say if a fault on your upstairs lighting circuit disconnected the supply to your fridge freezer
leading to the spoiling of the contents as well as this we've started connecting up more and more
electronic devices into our properties things like it equipment laptops and the like this kind
of device leaks a little bit of electricity to earth as part of its normal operation
however if enough of these devices are connected all those little currents can add up and cause an
rcd to trip when it doesn't need to a condition referred to as nuisance tripping so all of this
led us to a point where it's actually better to install a device called an rcbo for each circuit
now this is simply a device that combines an rcd and an mcb into one device offering the best and
safest solution with no circuits affecting any others and for a period of time this was viewed as
the creme de la creme of consumer unit protection however there's a couple more things to consider
which include the material that the consumer unit is made of now depending on when and where the
consumer unit containing them is installed the box may be made out of plastic which can melt if
a fire breaks out inside here meaning that the fire is not contained and can spread further
because of this new consumer units installed into domestic properties are made of metal so
that if a fire should break out in there it's contained and it won't spread in addition the
latest addition of the wiring regulations require that something called surge protection may need
installing into a new consumer unit in order to protect the delicate electronics in your
tvs washing machines boilers and other appliances from damage caused by surges in the electrical
supply so the modern consumer unit protects against overloaded circuits and it protects
users from the risks associated with electric shock the next generation of consumer units can
also identify other types of fault associated with loose connections and damaged cables
these new arc fault detection devices or afds are starting to make an appearance on the uk market
so looking at the consumer unit in your home you may be able to position it on the timeline
that we've considered in this video and see just how up-to-date your consumer unit is and
more importantly what level of protection it's offering to your home and the people inside it
if you've got an older board with fuses in it then you'll probably want to consider an upgrade which
would furnish you with protection against electric shock in the form of rcds and surge protection to
protect your valuable electronics contained in a metal unit to prevent the spread of fire
of course if you intend to have any electrical work done the best thing to do
is to contact a trusted local electrician to quote the work for you and explain some of the specific
things pertaining to your installation for further information please head to electrium.co.uk
all that remains in this video is to say thank you very much for watching