Motors 5 PSC motors - HVAC Online Training and Courses

and I just the other day I had a

question about PSC motors PSC motors

permanent split capacitor permanent

split capacitor motors what does that

mean well that's just a fancy way of

saying that it has a capacitor that that

that that motor has a capacitor that

uses a capacitor just like most of our

single-phase compressors just like most

of our condensers and evaporators fans

that are single-phase they're going to

use a capacitor so these capacitors we

have the two type of capacitors we have

a run capacitor and we also have a start

capacitor right now we're only going to

talk about the run capacitor what is the

purpose of the run capacitor we said in

a previous video that you're going to

have a compressor or let's say a fan

motor like this inside of here you're

gonna have a windings like this and then

you can have another winding like this

now one of these two windings is gonna

have more resistance than the other

because it has more resistance then

we're gonna say that that is going to be

our start winding the other winding on

this side which has less resistance

it's going to be my run winding now take

a look at the other video that I did

about finding out which one's your

common run and start connections because

I explained a little bit about the

windings but we have two windings this

connection right here this one is going

to be common to this winding and to that

winding so we have the three connections

in a let's say condenser fan motor and

that's a fan motor we're going to have

three wires coming out of it one is

going to be coming up like this then you

have one coming out like this

and then you've got to have this other

one like here and usually this one is

going to be a brown wire this is a brown

wire here now the brown simple easy

that's the one that always

goes where that's the one that always

goes to the capacitor in this case the

run capacitor the capacitor always feeds

the start winding check out my other

video I explained about this but my

capacitor always feeds I start winding

also another thing that's going to

happen is we're going to have let's say

for example l1 here

ly is gonna feed common then we're going

to have let's say l2 right here and

that's going to feed my capacitor and l2

is also going to feed my run winding one

thing I was saying they you should

remember is the same line that these the

run winding leads the capacitor and the

capacitor always feeds my star winding

this is how they always go wired if you

wire it up another way is just gonna

mess things up but now since we know how

this goes wired let's talk about what it

does let's talk about what it does we

know that we have seen this many times

in books we know that that is our sine

wave that is our sine wave like this so

now this right here and this example is

going to represent my voltage my voltage

higher voltage on this side so the

higher this goes the higher the voltage

you gonna have and then this is going to

be time how long does it take to go from

here to here now here in the United

States it takes 60 Hertz 60 Hertz but

what exactly does that mean well what

that means is that it is going to do

this one complete cycle 60 times per

second so by the time we say 1,001 1,002

1,003 1,004 1,005 every time we count

like that that's approximately one

second it has done this sixty times

that's pretty fast that's really really

fast so why do we need a capacitor and

what is the purpose of all of this

well the capacitor its doors in


the charge it's going to stored energy

and then it's going to discharge the

energy and gonna send it over to my

start winding when this happens the

capacitor makes the current lag some in

other words what it does is it creates a

little time delay so now you have power

coming in here and this creates a little

time delay so that it hits this winding

first which is this one here because of

that because of having the capacitor

here is gonna hit this one and then this

one this one and then this one so go

boom boom boom boom like that and the

magnetic field it's going to be changing

from here to here so and now when this

one is going to be north this one is

going to be self when this one becomes

south this becomes North so the magnetic

field is going to keep changing and the

rotor that is inside here is going to

rotate because now we're changing the

magnetic field and is not the same if we

didn't have a capacitor what would

happen is we would have a north and a

North here and then a South and a South

then a north and a north then a south

and a south so the pulse would be the

same now there's that time delay because

there's that time delay this rotor

actually rotates so what I am saying is

that we have this from the capacitor

this is from let's say for example this

case l2 but now we're gonna have another

one like this and this is going to be

from the capacitor right here

this is going to be for the capacitor so

now we get voltage hitting the run

winding voltage hitting the start

winding so now we can alternate between

the two and we get it to rotate so now

let's say that your capacitor happens to

be bad if you capacitor as bad and you

are not it's not doing anything what's

gonna happen now is you can get north on

both sides South on both sides north on

both sides

in both sides so that rotor what does

that rotor gonna do it's gonna sit there

and lock up he's gonna lock up and it's

not gonna do anything now typically what

I do when I get to a unit if I see that

the motors locked up

I'll give it a spin if I give it a spin

and it takes off there's a 90% chance

that it's going to be my capacitor

that's bad

now if the motor is completely locked up

then that tells me that is the bearings

these motors if you can give it a spin

yes it's going to be your capacitor that

is bad but how do we check a capacitor

we said on another video that you should

use a capacitor tester now some meters

they have a setting to check a

passengers and that's what you must use

a capacitor tester so this again this is

what a sine wave looks like your

capacitor is going to give you this

other sine wave because it slows it down

it holds it back because of that we get

the boom-boom effect so we hit nip from

both sides like this if you take the

capacitor out what's going to happen so

in other words this capacitor just is

open you're not going to get any power

going to this winding because this power

is not going to this winding this

winding is going to be energized all by

itself when that happens the rotor is

going to lock up and if you give it a

spin typically it will take off and it

will start running but remember you

always have to check the capacity you

can't assume that it is bad and how do

we test capacitor with a capacitor

tester now this is what the color run

capacitor there is such a thing as a

start capacitor I want to talk about

that in another video but this is your

uncle passed her that's basically what

it does this is what it's designed to do

inside of the motor now in the next

video I'll see if I can talk about the

star capacitors and tell you more about

them okay I hope this helped my name is

Julio please follow me on Facebook

subscribe to my channel on on the huge

on YouTube and hope to see you here if

you have any suggestions please let me

know of what it is that you would like

to see you not see if I can make the

videos again my name is Julio Eric Kahn

Academy thank you