Electric motor data plate interpretation

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Righty Tighty

Righty Tighty

Blame it on the dog
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Howdy, I have a machine that I'm getting set up, and I'm not understanding a couple of the things on the data plate.

Here's what I understand: it's a 3 phase motor, 440 volts.

There are a couple things I don't understand. It's stamped 15 / 19.5 kW. If it was stamped 15 PS, that would translate to about 20 kW. Did they just not stamp the "PS"?

Another thing I don't understand, are the two amperage ratings -- 25 / 33 -- and the two RPMs -- 1746 / 3504.

Can anyone explain? This appears to be a Dutch made motor.

20250210_161416.jpg
 
Thanks! Unfortunately, my shop doesn't have 440V service, so I can't use it. I'll be able to explain those numbers to the motor's future owner.

Part of me was hoping those numbers meant it was dual voltage....
 
Righty Tighty said:
Thanks! Unfortunately, my shop doesn't have 440V service, so I can't use it. I'll be able to explain those numbers to the motor's future owner.

Part of me was hoping those numbers meant it was dual voltage....
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You could run it on 460/3 power w/o a problem, but if all you have is 208-230/3…yeah. Then you’re screwed.
 
ProjectBazza said:
You could run it on 460/3 power w/o a problem, but if all you have is 208-230/3…yeah. Then you’re screwed.
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120 / 208 and 277 / 480 was what I remember, But maybe its "Y" vs Delta

440 to 480 is only 8% over nameplate
Righty Tighty said:
This appears to be a Dutch made motor.
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60 hz would be for North American electrical system
 
I appreciate the help. The shop has 240V 3 phase, so it looks like a motor swap is in order.

The silly part is that this machine has 2 motors - the one pictured, and one 30HP motor. The 30HP motor is dual voltage, and that's the one we looked at when purchasing the machine, so we assumed (yeah, I know) that both were dual voltage.
 
50,000 boat anchor or 5000 to rewind or replace a motor? Is it expensive?
 
I found a used replacement that's dual voltage for $250 locally. I'm not sure how much any of the electric motor shops here in town would charge to rewind one, but my hunch says it'll be more than that. I'll call around in the morning.
 
We used to have 75 and 125 HP 480v 3p motors rebuilt many years ago my recollection was in the 1-3000 range.

Of course they were 2 thresholds into the HVAC compressor room on the roof with no elevator access.
 

Tag should have RPM, frame size and HP listed
Looks like VEM is a German company
I’d look for a different motor
 
If you can drum up a 240/ 460 3 phase transformer, or 3X single phase ones you could use is.

I was never aware of such a motor that could be wired for different speeds. Speed in an AC motor, so far as I knew, was determined by the physical number of poles.
 
Thanks. I've been looking at step up transformers for some time, but that's out of the budget right now.

How would it work with 3 single phase transformers? Wire them in series? I'd likely have to consult a pro for that sort of install.
 
Dana67Dart said:
We used to have 75 and 125 HP 480v 3p motors rebuilt many years ago my recollection was in the 1-3000 range.

Of course they were 2 thresholds into the HVAC compressor room on the roof with no elevator access.
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Generally, unless it is a special mounting or application, anything under 50hp is probably cheaper to just replace, rather than rebuild. But sometimes you can get one rebuilt faster than you can get a new one in and time is money.

67Dart273 said:
If you can drum up a 240/ 460 3 phase transformer, or 3X single phase ones you could use is.

I was never aware of such a motor that could be wired for different speeds. Speed in an AC motor, so far as I knew, was determined by the physical number of poles.
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Two speed motors are pretty common in certain applications, especially machine tools. Seems it's more of a European thing too. For instance, my Austrian made EMCO lathe has a two speed three phase motor. This coupled with the three speed gearbox gives the lathe six speeds between 50-2000 rpm, with a much less complicated and less expensive gearbox. Now the rotary switch that reconfigures the windings to accomplish this is no joke. This 1.5hp motor is 230V three-phase, which I don't have at home so I made a rotary phase converter out of a standard 3hp three-phase motor. I have a 5hp rotary converter in the garage for the milling machine and anything else that needs it. I would prefer to use a single phase VFD on the lathe motor, but my understanding is that multi-speed motors don't like to be run by VFD, even if you aren't switching windings. I need to look into that more.
 
I need to consult the manual to see if there's a reason this two speed motor is installed. It's a different brand than the other motor, which raises my suspicion that one or both have been replaced. I'm just about ready to pull the trigger on the used motor I found, but I want to be sure it'll work for this application.

FWIW, the machine in question is a large drum sander for metal. One motor operates the belt, the other operates the drums.
 
Might be a reason you want two speeds on a sander, but I don't think I've ever seen that. Maybe wood vs. metal back in the day?? I know the modern belts hold up to metal at high speed but maybe the older stuff couldn't.
 
gzig5 said:
Might be a reason you want two speeds on a sander, but I don't think I've ever seen that. Maybe wood vs. metal back in the day?? I know the modern belts hold up to metal at high speed but maybe the older stuff couldn't.
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I don't know, either. I've used drum sanders for wood in the past, and none had multiple speeds.

This is my first "timesaver" type sander for metal, so I'm learning here. I don't remember if the motor in question operates the feed belt or the drums (this machine has two drums), but I could see a use for being able to change the speed on the feed belt.
 
67Dart273 said:
If you can drum up a 240/ 460 3 phase transformer, or 3X single phase ones you could use is.

I was never aware of such a motor that could be wired for different speeds. Speed in an AC motor, so far as I knew, was determined by the physical number of poles.
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Perhaps maybe look at it this way, Del;

You're familiar with rewiring a motor for different voltages, right? All you're doing is changing the wiring of the stators.

Here's a shot of the wiring connections on a multi-voltage 40 HP motor we have in the shop right now:

IMG_0965.JPG


IMG_0963.JPG


Motor has 9 leads, pretty common stuff.

We currently don't have a multi-speed motor in the shop, but...

Roughly speaking, on three phase motors (and @ 60 Hz, obviously):
* Synchronous RPM of a 2 pole motor is 3,600 RPM, and the motor has three leads (3 stator windings)
* Synchronous RPM of a 4 pole motor is 1,800 RPM, and the motor has six leads (6 stator windings)

So if you were able to re-wire all of the stators in the j-box (let's assume a 6-wire motor), you could change the RPM of the motor by simply changing the stators to/from series to parallel, if I remember correctly.

Now of course things aren't always this straightforward (and of course someone is bound to post an exception), but I run into multi-volt and multi-speed motors on an almost daily basis, and in my 3rd Grade Brain this is how I tend to think of (and remember) this stuff.
 
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If that's what a 3rd grade brain understands, then I must have a preschooler's brain.

I'm enjoying the discussion and education, and I thought I'd add that I picked up a replacement motor today. Gotta love a Baldor!
20250214_131255.jpg
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Anyway, back to the technical talk. Proceed, gentlemen. I've got my learning cap on.
 
That's 6hp shy of the motor on the machine, don't know how critical that is, mass/load wise. Current one is 20hp@1746rpm/26hp@3504rpm.
 
I was aware of that going into it, I'm going to run it and see how it performs. The machine is a sander and I'll be installing a soft starter, which should help on HP requirements on startup, and I don't plan on being very aggressive while using it. Just knocking off some dross from plasma cutting and general cleanup the finish.

We shall see....
 
How about a pic of this beast of a sander? I've got a 12" disk/6x18 belt combo Rockwell industrial sander that runs maybe a 2-3hp 220v single phase motor and for the most part, it plows through anything I throw at it. I can't imagine a sander that requires 26hp and what you'd need to feed it to bog it down.
 
ProjectBazza said:
Perhaps maybe look at it this way, Del;

You're familiar with rewiring a motor for different voltages, right? All you're doing is changing the wiring of the stators.

Here's a shot of the wiring connections on a multi-voltage 40 HP motor we have in the shop right now:

View attachment 1716366157

View attachment 1716366159

Motor has 9 leads, pretty common stuff.

We currently don't have a multi-speed motor in the shop, but...

Roughly speaking, on three phase motors (and @ 60 Hz, obviously):
* Synchronous RPM of a 2 pole motor is 3,600 RPM, and the motor has three leads (3 stator windings)
* Synchronous RPM of a 4 pole motor is 1,800 RPM, and the motor has six leads (6 stator windings)

So if you were able to re-wire all of the stators in the j-box (let's assume a 6-wire motor), you could change the RPM of the motor by simply changing the stators to/from series to parallel, if I remember correctly.

Now of course things aren't always this straightforward (and of course someone is bound to post an exception), but I run into multi-volt and multi-speed motors on an almost daily basis, and in my 3rd Grade Brain this is how I tend to think of (and remember) this stuff.
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So what do you do, change 1 set of stators 1 phase rotated in reference to the 1st set, to create more poles?

So far as I know, series vs parallel simply changes the voltage

Not that it matters, but I don't see how an RPM change would work. The windings should all be on the same respective poles, because whether lo or hi voltage, there's only 3 phases, and they must "hit" at the same time in order to pull. I have never run into this
 
67Dart273 said:
So what do you do, change 1 set of stators 1 phase rotated in reference to the 1st set, to create more poles?
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try this

https://control.com/textbook/variab...c-motor-speed-control/#animation_3phase_motor

or this

.

The fan blower motor in your AC system is capable of several speeds, mine can be set to 4-5 different speeds just by changing which 1 wire connects to the 120V AC supply terminal. Not sure how it is internally wound, might be that one wire feeds 2 poles and one feeds 4 etc. I recall from the Chrysler Master Tech video on wiper motors that the angle between the brushes changes the speed. It's DC so it might not be the same.

 
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