Help w/ Single Phase AC Motor wiring? (not HW)

In summary: They will tell you which wire is the ground. The red wire is the ground. In summary, the goal is to wire the motor and capacitors to a 120v plug, with a switch installed. The ohm readings will give you a clue as to which wire is the ground.
  • #1
MotorNewb
2
0
Hey all. I have an old garage door opener motor. Its a 1/3 HP, 1000 RPM, 115 volt, 3.6 amp, AC Motor (Am I correct in thinking its single phase?). I'm attempting to motorize a grain mill that I have in the kitchen. (the faster I can grind the wheat the faster my wife can make homemade bread right? ;)

I am following a similar design as this guy:
http://sdcollins.home.mindspring.com/GrainMill.html

The Motor is a bit older and the wires had a good layer of dirt over them when I pulled it out of the garage door opener frame. However with some cleaning up I've exposed 4 wires:

White, Green, Red, Brown (They are unmarked other then color and enter the motor casing by the same hole)(See attached diagram)

I also have salvaged the dual capacitor which has a yellow wire(attaching the two together), a blue wire attached to one, and a red wire attached to the other. (See attached diagram) Also, the capacitors are encased in plastic, not metal, and therefore do not need to be grounded?

GOAL: Correctly wire the motor and the capacitors to a normal three pronged 120v plug, with a simple switch installed. I'd also prefer the motor to spin clockwise.

I've searched the internet and spoken with friends but haven't been able to figure it out.
Any pointers would be appreciated!

Thanks!
 

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  • #2
Do the capacitors have a value marked on them that you can see?
 
  • #3
Yes,

GENERAL ELECTRIC
35F1150BA8
80-96 MFD
220 VAC 60 CPS
 
  • #4
I will assume that the green wire coming from your motor is a ground wire. You should verify it by using a continuity meter and checking to see if it is connected to the chassis of the motor. Most garage door opener motors are not meant to be run for long periods of time. They will overheat. So this could likely be pointless.
 
  • #5
The guys here can figure this out but they need some more information...
and it's a little hard to ask the questions succinctly.

so here goes -

do you have a multimeter that can read ohms? You can get one for $9.95 at Walmart.

could you make a matrix with all these ohm measurements in it?
the ohm readings should be one of three: zero, or infinite or just a few ohms- less than ten.

Difference between start and run winding ohms will be not very much. so be meticulous and use lowest ohm scale.
Before starting, check that meter reads zero with leads shorted together.


...Ohm Readings:.....
green to motor frame __ohms (hopefully zero)
red to motor frame (hopefully infinite)
brown to motor frame "
white to motor frame
"
red to brown
red to white
brown to white

red to green
white to green
brown to green

..end readings .......

lastly is there a switch on the motor that's actuated when the shaft gets to speed? Often this is internal to motor, look carefully.
A plastic capacitor is usually only for starting so there should be a switch, unless those caps are labelled "Motor Run". I have been unable to find that GE part number perhaps it's a special for the garage door company.

If you find the switch and can actuate it with a small dowel or something, see which of above ohm readings it changes. Repeat them all and add a second set of readings "with switch manually acuated"

another hint - when your ohm-meter is reading between two wires, twirl the motor shaft a little with your fingers.
If the two wires have a winding between them the ohmeter will deflect momentarily as you start to spin the shaft.
If the two wires just go into motor and are connected to same point, that is there's no winding between them, you won't see that brief meter deflection.

here's a link with a guess by a motor guy - see 'e bodine' and be aware he was guessing.
http://www.instructables.com/answers/Can-a-garage-door-motor-be-connected-directly-to-A/


Your ohm readings will be a big help.
 

1. How do I determine the correct wiring for a single phase AC motor?

The correct wiring for a single phase AC motor can be determined by referring to the motor's manufacturer instructions or by consulting a professional electrician. It is important to follow the wiring diagram provided by the manufacturer to ensure safe and proper operation of the motor.

2. What is the difference between single phase and three phase AC motors?

The main difference between single phase and three phase AC motors is the number of power supply lines. Single phase motors have two power supply lines, while three phase motors have three power supply lines. This affects the motor's power and torque capabilities, as well as its wiring and control requirements.

3. How do I connect a single phase AC motor to a power source?

To connect a single phase AC motor to a power source, you will need to identify the hot and neutral wires from the power source and connect them to the corresponding wires on the motor. It is important to ensure that the voltage and amperage of the power source matches the motor's requirements.

4. Can I reverse the direction of a single phase AC motor?

Yes, the direction of a single phase AC motor can be reversed by switching the connections of the hot and neutral wires. However, this may require additional wiring and components depending on the motor's design and application.

5. What are some common mistakes to avoid when wiring a single phase AC motor?

Some common mistakes to avoid when wiring a single phase AC motor include incorrect wiring connections, mismatched voltage or amperage, and using incorrect wiring diagrams. It is important to carefully follow the manufacturer's instructions and double check all connections before powering on the motor.

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