Longshot: does anyone know how to change poles on a 3phase motor?

[jbailey]

Hey, not shooting related but you guys are collectively pretty smart, so maybe someone can help me.

I have 50yr old power feeder that feeds wood into a spindle shaper. It is a 1 HP, 220volt, 3 phase unit, made by a German co. Holz that is no longer in business, or if they are, they aren't making power feeders. The manual is in German, very technical German, which I can read (mostly).

I want to change the poles from 4 to 2, in order to get a slower feed speed. I think the attached diagram explains how to make this switch. Does anyone know if this diagram illustrates this switch, and if so, how would I actually do it (the manual just says to look at this page).

Thanks much, appreciate any input.

 

[mheimer_45]

Someone a lot smarter than me will chime in but from the looks of just put the wire from VA onto VB and the wire from UA onto UB. And the wire from WA onto WB. Position the motor the same as the diagram while looking at it.

On a side note I’m not an electrician and you may be seriously killed. But I’ve done this a few times on the farm.

 

[Wisconsinner]

A 4 pole motor will run at a lower rpm with more torque. A 2 pole motor will run at higher rpm with less torque. If it's already set up in a 4 pole configuration that's the slowest speed you are going to achieve.

 

[Hobo Hilton]

I'm not sure how far from you these guy's are located. This is who I would ask a question like that. Just go in there and one of the apprenticeship teachers would enjoy looking at that schematic.

IBEW 26

 

[Mk16.5]

Buy an VFD inverter. Run any 3 phase at almost any speed. They look like this:

https://www.amazon.com/Variable-Frequency-Drive%EF%BC%8CMYSWEETY-Converter-VFD-2-2KW/dp/B07D76365G/ref=sr_1_3?dchild=1&keywords=3+phase+inverter&qid=1615340568&sr=8-3

 

[2aBaC̶a̶]

I'm not sure how far from you these guy's are located. This is who I would ask a question like that. Just go in there and one of the apprenticeship teachers would enjoy looking at that schematic.

IBEW 26

Lol,

Better luck taking it to an electric motor or pump shop.

That doeant look like a normal electrical schematic. Is there any more diagrams of info?

What do the actual wire leads on the motor look like? Can you take a picture of them and the nameplate?

 

[Bullfrog08]

A 2 pole motor has one magnet on each side of armature, and a 4 pole has 2 magnets on each side. 4 pole will be higher torque. Move leads from a to b to switch between 2 or 4 pole wiring. Youll have to switch it to test your rpm speed, could be close to the same speed.

 

[2aBaC̶a̶]

What I typically see on 3 phase motors is a high and low voltage and that determines wiring and rpm.
For example:

 

[gta_spec]

VFD is the way to go. Awesome little things.

 

[missed]

U,V,W(a) is wound for 4 pole
U,V,W(b) is wound for 2 pole which will be the higher speed.

This is a squirrel cage motor. There are no magnets in it. Voltage will not change motor speed. Only way for speed to change in a AC squirrel cage motor is poles or frequency.


If you want to slow it down more than the 4 pole can provide this would require regearing the feed mechanism.

Or VFD. Wire up the drive with the 4 pole motor connection.

Challenges with VFD especially with older motors is they do not provide the torque at the lower rpm's that the newer inverter rated motors will. Also cooling is not as efficient for the older motors at lower than rated RPM.

I have put plenty of drives on older non inverter duty motors. Always keep them on the lower voltage range, stay out of the lower sub 50% rpm range as much as possible.

In many cases a drive can extend the life of motors and machines as you reduce locked rotor amperage, acceleration rates are lower, among other items.

 

[Silverjay]

U,V,W(a) is wound for 4 pole
U,V,W(b) is wound for 2 pole which will be the higher speed.

This is a squirrel cage motor. There are no magnets in it. Voltage will not change motor speed. Only way for speed to change in a AC squirrel cage motor is poles or frequency.


If you want to slow it down more than the 4 pole can provide this would require regearing the feed mechanism.

Or VFD. Wire up the drive with the 4 pole motor connection.

Challenges with VFD especially with older motors is they do not provide the torque at the lower rpm's that the newer inverter rated motors will. Also cooling is not as efficient for the older motors at lower than rated RPM.

I have put plenty of drives on older non inverter duty motors. Always keep them on the lower voltage range, stay out of the lower sub 50% rpm range as much as possible.

In many cases a drive can extend the life of motors and machines as you reduce locked rotor amperage, acceleration rates are lower, among other items.

Spot on. End winding insulation may have a problem with VFD and older insulation.

 

[1moaoff]

Is it a standard mount?

 

[1moaoff]

What I typically see on 3 phase motors is a high and low voltage and that determines wiring and rpm.
For example:
View attachment 7577973

I blew up like 4 of those in single phase. 8 years ago they had alot the the caps on wouldnt take the crazy voltage from generators. Long story but the caps blew in a most surprising fashion.

 

[missed]

Is it a standard mount?

It's Pre-NEMA standards if it was manufactured in the 50's. Plus it's German. Germans and electrical equipment.....ummm they do shit a " special" way.

If you want to find a replacement motor send me the bolt pattern, shaft size, KW rating, some pictures.... I'm sure I can find something close.

A PI test can help determine insulation health, but it's not definitive as you dont have a baseline. Keeping the incoming voltage on the lower end and a quality drive it should be fine.

I ran my 1930's Monarch lathe on a drive for years. It was a 220/440 volt motor, ran it on 220 and it was happy as could be. I did PI that prior to installation, it was within specs on a non inverter duty motor from the IEEE guidance.

 

[addertooth]

Some people just install a VFD (variable frequency drive), to adjust the speed of multi-phase motors.

 

[FXDWG]

VFD+old motor=bearing fluting

VFDs and 3 phase motors are cheap these days

 

[jbailey]

Yes, I knew you guys were smart. Damn this forum can solve a lot of issues.

Here is the page in the manual detailing this

and here is pic of the voltage scheme like @2aBaCa posted:

I'm not looking for you guys to read that German as I have a pretty good command of the language. What it basically says is the motor can run at 8 speeds, and to get all 8 you need to change the gears, the power switch and the poles on the engine. I can change the gears and the power switch, but I can't change the poles. And in order to get the feed speed I need (~2 m/min), that speed is only possible by changing the poles.

The power feeder is running at 220V and it is correctly set up for that per the diagram.

I would be scared to get a VFD and I don't know what "mount" it has. I was hoping I didn't have to replace the motor or the entire unit, because it is working great (the entire power feeder is great - lots of power, the mounting arms is super strong steel with lots of adjustment points).

So I think I understand that 2 poles will be faster than 4 poles, so the motor is likely wired for 2 poles right now, requiring me to rewire to 4 poles. In order to do this, I have to find out where these connections are made to the motor and rewire them per that diagram??

again thanks to all, very interesting stuff.

 

[LeftyJason]

Yes, I knew you guys were smart. Damn this forum can solve a lot of issues.

Here is the page in the manual detailing this

View attachment 7578273
and here is pic of the voltage scheme like @2aBaCa posted:
View attachment 7578276

I'm not looking for you guys to read that German as I have a pretty good command of the language. What it basically says is the motor can run at 8 speeds, and to get all 8 you need to change the gears, the power switch and the poles on the engine. I can change the gears and the power switch, but I can't change the poles. And in order to get the feed speed I need (~2 m/min), that speed is only possible by changing the poles.

The power feeder is running at 220V and it is correctly set up for that per the diagram.

I would be scared to get a VFD and I don't know what "mount" it has. I was hoping I didn't have to replace the motor or the entire unit, because it is working great (the entire power feeder is great - lots of power, the mounting arms is super strong steel with lots of adjustment points).

So I think I understand that 2 poles will be faster than 4 poles, so the motor is likely wired for 2 poles right now, requiring me to rewire to 4 poles. In order to do this, I have to find out where these connections are made to the motor and rewire them per that diagram??

again thanks to all, very interesting stuff.

Rough intro to vfds. He is pretty good explaining how motors work.

 

[2aBaC̶a̶]

Wish I could read German. I may try to translate it later.

@jbailey is there a peckerhead on the motor where its wired? There might be more wires in there with labels printed on the jacket. Or different studs for wiring.

 

[LeftyJason]

Wish I could read German. I may try to translate it later.

@jbailey is there a peckerhead on the motor where its wired? There might be more wires in there with labels printed on the jacket. Or different studs for wiring.

Here is what Google says.

 

[MadDuner]

I blew up like 4 of those in single phase. 8 years ago they had alot the the caps on wouldnt take the crazy voltage from generators. Long story but the caps blew in a most surprising fashion.

Nothing likes the startup voltages of a generator if you try to power something before it’s at speed. Same thing for shutting a genset off under load....

 

[2aBaC̶a̶]

Is the manual available as a pdf? im not seeing the wiring diagram for speed changes.

Maybe something like this.

What does the wiring on the motor look like?

Something like this? Are the wires labeled?

 

[jbailey]

I have this diagram, which I believe shows how to wire for 220V or 440V. I'm wired for 220V and that is the voltage I'm feeding it.

This is a picture of the wires right below the "off/on speed 1/on speed 2/on reverse speed 1" switch.

There appears to be sticker labels on those little wires and nuts. The access to the motor is somewhat limited beyond this box hanging off the front of it...

 

[2aBaC̶a̶]

That is the peckerhead. All of the wiring for the motor is done there. Its where you're going to wire for the different speeds. Just need to figure out which terminals go where.

I have this diagram, which I believe shows how to wire for 220V or 440V. I'm wired for 220V and that is the voltage I'm feeding it.
View attachment 7579035

This is a picture of the wires right below the "off/on speed 1/on speed 2/on reverse speed 1" switch.

View attachment 7579040
There appears to be sticker labels on those little wires and nuts. The access to the motor is somewhat limited beyond this box hanging off the front of it...