have you ever wondered why there are so many different voltages that mean the same thing
what's up everyone i am dustin stelzer with electricianu so let's talk about this whole
voltage thing so a lot of times you're going to come across people saying 110 115 120 125 volts
and we're really just talking about the same thing so why are there so many different things well
there's different classes so some equipment will use things differently some power that is supplied
from a utility company is going to be kind of in a range so there's nominal voltage there's
utilization voltage uh there's distribution voltage there's a bunch of different voltages
so when we talk about these things we're kind of saying the same thing but there are very specific
reasons why these numbers exist so a long time ago back when we really started using power in the u.s
the u.s power system was at 100 volts and they were using 100 volts out in public
street lighting but then as time went on people wanted the lights to be brighter so they would
bump the utility voltage up to 110 volts and this is where the whole 110 220 thing comes
from this is what it was at for a very very long time and then probably within the last like 50
or 60 years it was bumped up even more for the same effect to try to get a little bit brighter
street lights so we went up to 120 and 240. and for the majority of people out there when we
talk about things that is what we're talking about nowadays that is the modern convention
but you'll notice that materials have a little bit different voltages with them as well so regardless
of the nominal voltages that we may talk about out in the field like hey is there 120 at that
that receptacle or hey is there 110 people still just use 110 and they still use 220. usually a
little bit older people that have been around a lot more where that whole nomenclature was was
still kind of during transition when they first started their career but nowadays it's really not
110 and 220 it's 120 and 240 but you will notice that there are some materials out there that have
things like 130 volts there's a lot of lamps and bulbs that are meant for commercial use
that are rated at 130 because voltage can kind of fluctuate throughout a property
throughout the day with usage so the more things that are being utilized there might be voltage
drop there might be raised voltages so a lot of lamps bulbs will burn out if they're not rated
to be able to handle a little bit higher current because of the higher voltage that's happening
now before we get into it too much i want to remind everybody that we have continuing education
available so we are getting more and more states added throughout the rest of this year i think we
have 10 states now that we're approved in so if you want some continuing education you're
tired of the same old crap all the time come to electrician you come check out see if we have
your state available and if we don't keep checking back because we are constantly adding more states
now normal supply voltage from utility company is going to be within a certain range it's not
going to be guaranteed to be at the same thing at all times there's a lot of other things going on
in an area that might affect what the actual delivered voltage is but they tend to stick within
about 114 volts to 126 volts this is what you would call the utility voltage or the
distribution voltage at that property so they know that anywhere within that range if they've got a
voltage of like 124 or 118 equipment's still going to operate the same way there are little
fluctuations most equipment is designed to still operate within this range so if you have something
that has 114 volts with your multimeter and you're going to plug a vacuum cleaner in there or if you
have 124 volts that vacuum cleaner is still going to operate without there being any damage to it so
that's why there's kind of an acceptable range but really the things that need to be looked at
are the issue of voltage raising and the issue of voltage dropping so in the case of voltage
rising you'll notice that you have things like receptacles or plugs cords that are
usually designed at 125 and 250. so if you look at a receptacle some of them are just rated at
125 volts 20 amps or 125 volts 15 amps some of them are rated 250 volts 50 amps or 250 volts
30 amps so that amperage number is still saying that this is the amount of current that's designed
to be drawn through the device but the voltage is typically on the higher end and that's because
when voltage rises there's a directly proportional relationship with amperage if you raise the
voltage you're going to raise the amperage too so they're saying that even though a nominal system
of 120 volts might have 118 might have 122 they're saying that the maximum voltage that this device
can handle because of the amount of current that's going to be drawing through it is 125
and some receptacles you'll notice will say 125 250 that means that this one receptacle is
designed regardless of the prongs that are being plugged into it you know those will have to match
up but you can feed 125 volts through this or you can feed 250 it's designed to carry both
now if voltage goes down then current is going to go down so there's no worry about any damage to
a receptacle if there's less current flow because of less voltage then we notice things like motors
which are kind of inverse of that we notice motors are usually rated at 230 and 460 volts
so 230 is obviously representative of the 240 volt 250 volt range but it's lower it's
on that low side and then 460 the same thing we often have like a 277 480 volt service somewhere
but instead of saying 480 on that motor it's going to say 460. and the reason is is because
there's voltage drop that occurs when loads are turned on and so manufacturers of motors
always know that there's generally going to be like a plus or minus five percent in voltage
and so when they rate a motor at a certain voltage they're saying that we're giving you the low end
of what the voltage is that this motor can operate without there being any kind of large damage or
anything to it they don't worry about it so much on the high end it's more of a concern on the low
end because at a certain point if you keep going lower then that motor's not going to operate well
it's the same thing if a motor goes too fast and starts operating a lot higher that it can it can
also damage things but with motor ratings they're always concerned about that low end because
voltage is has a lot more uh tendency to drop especially in an area with a lot of things going
on or at a facility a lot of things happening the more loads that you have on you're going to start
dropping the overall voltage at that facility so they're saying at what point will this motor stop
working and that's why they give us the lower values of 230 and 460. so typically when you're
seeing voltages just as a little bit of a review you're not going to see equipment really with 110
and 220 on it most of the time when people are saying 110 220 that's just some old school
language for the modern times of saying 120 and 240. you will have things that are rated 230 460
and that tends to be motors you're going to have receptacles that are rated at 125 and 250 but just
generally in there we're talking about voltage classes so hope you learned something thank you
guys so much for watching really appreciate your attention and i will see you in the next one
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