Hello All, this is my first time posting here on this wonderful forum. I have here a grundfos motor that allows wiring the stator poles to select speeds. It is a 3-Speed 900 / 720 / 530 rpm 220V 50Hz with 16uF 400V Capacitor and 0.22KW Size Motor. It is perfect for my application but it is my first experience with anything of this sort therefore seeking some help or suggestions as to what is realistically achievable.

There are two parts to my question. Images are attached below.
1. I want to add toggle switches(?) to be able to adjust speed (Low-Med-High) - this motor was salvaged from some heating/cooling equipment a while ago as i was told and doesn't come with anything else but the speed control wiring diagram on the box.
2. The Speed setting diagram on the back of the electrical box is confusing to me, but i can understand that changing between speed 1 and speed 2 only requires the capacitor Wire to be attached to U1-U2 instead of U1-V2

Diagram for speed 1 and speed 2 there seems to be two jumper wires from U2-W1, does this mean i have to physically use two wires to jump the two terminals?
Dotted lines that denote MAIN1 MAIN2 and AUX, i have no idea what they mean.

Lastly, i can tell you the extent of my knowledge. I'm a tinkerer and a hobbyist but all my experience has been with dc related led's, pcb's and led circuits so this is (very) new to me.
Thank you for reading through my question, i hope you can take some time to answer a few things.
Best regards,
Scholl

 

Main1, main2, and aux are the windings of the motor and the thing labelled 't' is an over-temperature switch. These are wired internally to the brass strips at the top of terminal block.
I don't know why some of the links are shown doubled but there would be no point in using two wire links. The picture of the actual terminal block shows it wired for speed 2 and it uses only single wire links.

 

Thanks for the explanation on the windings. I've successfully set it to speed one and interestingly the rpm is the same whereas it is a lot quieter and draws much less current (0.4Amps - 220V) instead of 1.66Amps at speed 2. The motor can be stopped by hand on speed 1 whereas it feels a lot more powerful on speed 2 and i can't stop it by hand, speed 3 seems to be even louder but rpm stays the same.

I also need to reverse the rotation of the motor.

 

To reverse direction reverse the Aux winding wires.

You may find it wont work as effective because the impeller will be going backwards.

 

but rpm stays the same

The no load RPM stays the same but the torque/power changes. When the motor is actually driving something the speed will change depending on the speed settings.

 

Appreciate the help gentlemen, this place is truly a blessing to people like me who want to learn.

The no load RPM stays the same but the torque/power changes.

Is there a way to set it up for variable speeds (900 / 720 / 530 ) under no-load conditions.

 

Is there a way to set it up for variable speeds (900 / 720 / 530 ) under no-load conditions.

The coils and capacitor set up a rotating magnetic field, the rotation speed is set by the mains frequency.
With no load it is almost a synchronous motor - the rotor follows the magnetic field round. When loaded, the rotor slows down. The slip between the magnetic field rotation and the rotor generates power. the greater the slip the higher the power.
The three speeds of the motor are set by changing the strength of the magnetic field. With a stronger field, more power is generated at lower slip and so the motor runs faster on load.
It is not easy to electronically control the speed of such a motor. The best method is variable frequency supply but this is neither simple to build nor cheap to buy.

 

It is a 3-Speed 900 / 720 / 530 rpm 220V 50Hz with 16uF 400V Capacitor

The speeds in these motors are generally obtained by changing the pole count.
Max.

 

Grundfos website gives limited information but according to the literature it is supposed to be a 6-pole motor. i.e: 80B6-19-B

80 - Frame Size
B - Length of Stator Core
6 - No. of Poles
19 - Shaft Diameter
B - Model

In order to obtain L-M-H function, reducing pole count means i'll have to remove wires of Main1 or Main2 windings?