How do I connect this reversible 120v AC motor?

Thread Starter

Othello7

Joined Sep 18, 2018
24
I'm sorry I don't quite know how to connect it. I don't have that much knowledge on AC motors. a simple circuit diagram would be appreciated.

Do I put the capacitor in series with the motor? Do I have a lamp? Does it mater which wires?
I don't exactly understand how I am supposed to do this. the best I know is to just connect the wires so I will need a little more information for this.

Thanks for all your help.
 

dendad

Joined Feb 20, 2016
3,939
Connect the capacitor between Black and yellow.
Try line to white.
neutral to Black for one direction, Yellow for the other.

AC Motor.jpg

That may work.
The lamp will go in the wire from Line to White if you want to add that.
 

Attachments

MisterBill2

Joined Jan 23, 2018
9,877
You're right! I thought that all the wires just disappeared into the other side but now I see that the blue one went under and connected to the little metal box thingie staped to the side of the coil. so that means the blue wire is not needed?


I connected a few other 120v AC motors that worked fine without anything. but I connected one between the wrong two wires and it blew. would that prevent damage from that or is it just for when I am planing long term use?
The thermal protector in the line means that it is a main power connection, one side of the power feed. So you would connect one side of the line to the blue wire. And I still suggest searching on line for a circuit diagram of the dryer. That would solve your problem.
If you still have the dryer and there is a circuit drawing someplace on it, such as inside the top control panel, that also could give you all the information that you need.
 

Thread Starter

Othello7

Joined Sep 18, 2018
24
thanks for the diagram and explanation. but I still am a bit confused, now I am being told to use the blue wire? how? so I tried connecting it the way you said and... nothing. tried it the other direction... nothing but buzzing still. I accidentally connected it wrong, I thought I heard a poping noise and the buzzing was a lot quieter, still nothing. Is it possible to connect the capacitor backwards?

What now?

The thermal protector in the line means that it is a main power connection, one side of the power feed. So you would connect one side of the line to the blue wire. And I still suggest searching on line for a circuit diagram of the dryer. That would solve your problem.
If you still have the dryer and there is a circuit drawing someplace on it, such as inside the top control panel, that also could give you all the information that you need.
I do not quite fully understand what to move to the blue wire. The, dishwasher, was old and I don't have anything left except the motor. I found an old document on it a long time ago but it didn't help much as I recall. like he said, I think i'll just have to try combinations.
 

Ylli

Joined Nov 13, 2015
1,053
The, dishwasher, was old and I don't have anything left except the motor. I found an old document on it a long time ago but it didn't help much as I recall. like he said, I think i'll just have to try combinations.
Doing a google search on "FSP Part No. 303574" turned up a couple of dishwasher models that it could have been. Unfortunately, I was unable to find wiring diagrams for any of the dishwasher models I found.
 

Ylli

Joined Nov 13, 2015
1,053
I propose that the internal wiring looks like this:
Capture.PNG

Thinking W1 is the main winding, and W2 is the start/run winding for one direction and W3 is the start/run winding for the other direction.

Connect the incoming power between the blue and the white leads. Connect your capacitor between the blue and yellow, leave the black unconnected. Be sure you have that incandescent bulb still an series and see what happens.

Keep in mind that we are flying blind here, and the above is just a guess. Won't be surprised if it doesn't run.
 

MisterBill2

Joined Jan 23, 2018
9,877
One other possibility is that it is a motor that used an external starter relay, like most refrigerator compressor motors still use. And the circuit of the dishwasher would more likely be found on one of those service information websites than on a motor website. I came across such a site while searching for the circuit of a video game power supply, no clue how that happened.
The relay starter option changes a bunch of considerations, since that means that one winding could be the run winding and then the other two could be "start" in opposite directions. Sorry, but right now it is very early morning for me and I can't think of how that gets done.
 

Ylli

Joined Nov 13, 2015
1,053
One other possibility is that it is a motor that used an external starter relay, like most refrigerator compressor motors still use. And the circuit of the dishwasher would more likely be found on one of those service information websites than on a motor website. I came across such a site while searching for the circuit of a video game power supply, no clue how that happened.
The relay starter option changes a bunch of considerations, since that means that one winding could be the run winding and then the other two could be "start" in opposite directions. Sorry, but right now it is very early morning for me and I can't think of how that gets done.
This is the direction I was heading MB2. One of the wiring diagrams I did find had a motor with two windings - one the main run winding and the other one a start winding driven from a relay (controlled by main winding current draw).
 
Last edited:

MisterBill2

Joined Jan 23, 2018
9,877
This is the direction I was heading MB2. One of the wiring diagrams I did find had a motor with two windings - one the main run winding and the other one a start winding driven from a relay (controlled by main winding current draw).
It does seem like a reasonable possibility. One thing now would be an additional inspection of the motor to see how many leads connect to each of the wires. Many times the starting windings are a heavier gauge so as to have some phase shift, and to allow a stronger magnetic field as the motor accelerates. Sometimes the close examination will provide a number of answers.
 

MaxHeadRoom

Joined Jul 18, 2013
23,945
I would second the set up in #27.
The start windings are usually smaller gauge/higher resistance as the higher current flows in the run winding as it is lower resistance.
Max.
 

MisterBill2

Joined Jan 23, 2018
9,877
I would second the set up in #27.
The start windings are usually smaller gauge/higher resistance as the higher current flows in the run winding as it is lower resistance.
Max.
I have no idea as to how I missed that post. It certainly makes sense. But how to specify the start relay? I am thinking that it probably does need one. And what sequence for the initial checkout? Power between blue and white, with momentary connection between blue and black??? But not for more than 5 seconds first try. Then, after it stops, power between blue and white with yellow connected to blue momentarily?? If the rotation is the opposite then a lucky guess based on assumptions that were correct.
 

MaxHeadRoom

Joined Jul 18, 2013
23,945
It could even be PSC (permanent start cap motor) and the start winding permanently powered, it would be very easy to power up this way a then disconnect the start winding and see if it continues to run OK denoting a current-sense start relay could be used.
Using ~10μf for start cap on one of the 6.5Ω winding's..
Max.
 

MisterBill2

Joined Jan 23, 2018
9,877
It could even be PSC (permanent start cap motor) and the start winding permanently powered, it would be very easy to power up this way a then disconnect the start winding and see if it continues to run OK denoting a current-sense start relay could be used.
Using ~10μf for start cap on one of the 6.5Ω winding's..
Max.
Max is right, I had not considered that option. Good thinking, Max.
 

Thread Starter

Othello7

Joined Sep 18, 2018
24
A motor capacitor can be connected ether way, what is the value?
It should be motor start rated.
Max.
It was borrowed from my old food processor. it was used to start its motor so I thought it would work.
It says on it:
EPCOS
MOTOR START
CE 150 VAC 120μF
B42750-A1127 -A
(on the back)
09.01

I propose that the internal wiring looks like this:
View attachment 160411
Thinking W1 is the main winding, and W2 is the start/run winding for one direction and W3 is the start/run winding for the other direction.

Connect the incoming power between the blue and the white leads. Connect your capacitor between the blue and yellow, leave the black unconnected. Be sure you have that incandescent bulb still an series and see what happens.

Keep in mind that we are flying blind here, and the above is just a guess. Won't be surprised if it doesn't run.
I tried it. and the MOTOR SPUN! Ever so slightly. I gave it two, half-second, pulses it spun very slowly and didn't look very powerful. but it worked.
We don't seem to have any spare lamp sockets so I guess I will just try without that. the reason I stopped powering it so quickly was because it made a poping noise when it was unpowered. I don't know if I'm doing it wrong but its a start.
 

dendad

Joined Feb 20, 2016
3,939
The popping noise could be the spark as the switch opens or wire was disconnected. It can be a pretty big spark.
And it may be the motor does not need a capacitor but usually has a start switch, as mentioned previously.
If that is the case, once it is running, just having power across the blue and white would keep it going, with the other wires not connected now, only connected for starting.
Just another guess ;)
 

MisterBill2

Joined Jan 23, 2018
9,877
120μf sounds like a start capacitor for that size of motor, if so it should just be used for starting and then taken out of circuit.
Max.
I just replaced a run/start capacitor on a furnace blower motor, it was only 10Mfd. Bigger is not always better. And I am still wondering if that other wire caused it to run in the opposite direction.
 

Ylli

Joined Nov 13, 2015
1,053
I tried it. and the MOTOR SPUN! Ever so slightly. I gave it two, half-second, pulses it spun very slowly and didn't look very powerful. but it worked.
OK, first things first. Remember that you are playing with line voltage. Getting across line voltage *can* cause injury or even death. If you are not using the series bulb (I'd recommend a 100W bulb at this point), then you may get an arc, and an arc creates ultraviolet light which can cause eye injury.

Leave the yellow and black disconnected. Apply line voltage to the white and blue wires. The motor should buzz loudly. Now momentarily connect the yellow wire to the blue and then then disconnect it again. Is the motor running? If so, note the direction and remove the power.

Now do it again, this time using the black wire instead of the yellow. Momentarily connect it to the blue wire to start the motor. Does it run in the opposite direction?
 
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