Help Identifying 3 Phase Baldor Motor for VFD

Hello,

I wasn't sure where to post this, but since it has to do wanting to use a VFD with my bandsaw, I posted it here. Please let me know if there is another section of this forum where my question would be more appropriate.

A few days ago I purchased an old Walker-Turner 14" bandsaw that came out of a Machine shop that closed down. The saw looks to have been modified at some point and the motor currently in it is a Baldor 3 Phase motor. I want to purchase a VFD to run it off of single phase 220, but cant find any specs anywhere on this motor.

Is there anyway I can identify if its 220 vs 440 and the HP rating by looking at the dimensions/style of the motor, wire gauge and or switch and plug?

Thanks

A start would be to get the cover off the box on the motor and see what is what.

Three phase dual voltage motors often have nine wires exiting motor, all tagged with a number

An often found lash up for 220/230/240 will be:

Line 1 to T1 and T7
Line 2 to T2 and T8
Line 3 to T3 and T9
T4, T5 and T6 together but connected to nothing else

johnoder said:

A start would be to get the cover off the box on the motor and see what is what.

Three phase dual voltage motors often have nine wires exiting motor, all tagged with a number

An often found lash up for 220/230/240 will be:

Line 1 to T1 and T7
Line 2 to T2 and T8
Line 3 to T3 and T9
T4, T5 and T6 together but connected to nothing else

Click to expand...

Got it! I'll snap some pictures and report back. Thanks.

Most likely it is a 1 HP motor, if the folks setting it up did things right. I say this because it has a simple 3 phase switch, with no apparent motor overload protector, which can be done up to 1 HP if the motor has an internal protector (thermal switch).

Probably 230V, as the plug is one that should be 230V max (and needs to be tossed in the trash).

Taking off the cover on the motor wiring box may reveal a wiring diagram on the inside of the cover. Or not. If not, follow what johnoder said.

OK! Was able to locate the motor tag, and shift the motor enough to get a decent picture. Now we know what were working with. It’s a 1/2hp 220/440 motor. I’m not really sure what that means in terms of selecting a VFD though. I guess at this point I can’t rule out just swapping for a single phase motor. I just don’t know how to select one that the bolt holes will line up with. I did get to test the machine prior to purchasing and it ran smooth and quiet, so I know the motor is good.

I think I’m going to keep the whole jack shaft setup. Upon closer inspection today, I have to say the whole setup was done really well. The motor is bolted to a piece of ¼” plate that is hinged on one the bottom. It’s attached to the inside back wall of the machine’s base. There’s a knob on the outside that pivots the motor up and down. This allows for tensioning and loosening of the belt that runs from the motor to the large single pulley on the jack shaft.

The original motor mount is still in place. They fabricated a plate that the pillow blocks, shaft and pulleys are attached too. This plate is mounted to the original mounting holes for the motor. To tension or loosen the belt on the step pulley you simply loosen the nut on the motor mount plate and raise and lower the whole jack shaft setup. I normally don’t like custom jobs, but in this situation everything is machined nicely and is robust, and it looks like everything could be brought back to stock with the exception of a single hole on the back of the base where that adjustment knob sticks out of.

Here are pics of the data plate and the wiring in the junction box.

Without taking the tape off you can tell what volts its "connected" for. If THREE bundles have ONE line wire and ONE motor wire, its high volts

If THREE bundles have ONE line wire and TWO motor wires, its low volts

johnoder said:

Without taking the tape off you can tell what volts its "connected" for. If THREE bundles have ONE line wire and ONE motor wire, its high volts

If THREE bundles have ONE line wire and TWO motor wires, its low volts

Click to expand...

How do I identify which wires are which in this instance? I don't see any markings on the wires.

The line wires are those come thru the hole in the side of the box. Appears to be SO cord style cable

The motor wires come thru the hole in the bottom of the box

johnoder said:

The line wires are those come thru the hole in the side of the box. Appears to be SO cord style cable

The motor wires come thru the hole in the bottom of the box

Click to expand...

I know that part I just ordered a TECO VFD and I believe it has to be wired into this motor. Since it's 3 phase I thought I would have to identify the wires so that they are connected in the correct terminals on the VFD

GarageGuyNY said:

I know that part I just ordered a TECO VFD and I believe it has to be wired into this motor. Since it's 3 phase I thought I would have to identify the wires so that they are connected in the correct terminals on the VFD

Click to expand...

To look for motor wire tags you remove all tape

johnoder said:

To look for motor wire tags you remove all tape

Click to expand...

I'll look carefully for those. I imagine they wont be legible after all these years. I ordered the Teco VFD Model #: L510-101-H1-U. Should arrive on Monday or so.

GarageGuyNY said:

I know that part I just ordered a TECO VFD and I believe it has to be wired into this motor. Since it's 3 phase I thought I would have to identify the wires so that they are connected in the correct terminals on the VFD

Click to expand...

No, it's not that important actually. The three wires going to the VFD can go to any of the load terminals of the VFD. Run it, and if it turns the wrong direction you can either swap any two of those wires, or just tell the VFD to run the other direction.

What you really need to know is the voltage that the motor is connected for.
So look at the diagram below;


From what I see in your photo, there appear to be three wires on the top that are joined together, but NOT joined to any wires coming from the cord. That would fit the upper diagram (Wye connected motor) and the LOW voltage connection; 2 leads on each of the three wires of the cord, the remaining 3 leads connected together. That would be the 220V connection, meaning you are good to go.

I'd get rid of that cord cap though, it's seen better days. And if the cord is old and cracked, replace it now rather than AFTER the fire...

Actually looking at it some more, you MUST replace that cord, it's not only illegal (because of the colors), they used the green ground wire as one of the phase conductors, meaning you have no ground connection to the motor. Very unsafe. You need 4 conductor cord, and secondly, running SO cord off of a VFD turns those conductors into a radio broadcast antenna, which your wife and neighbors may not like. Use shielded cable or armored cable and ground the shield / armor.

This is really great information. Thank you.

I will be replacing all the wiring in the machine that goes to the motor. I'm brainstorming ideas of how to set this all up. What I'd like to do is house the VFD in an enclosure of some sort like a metal junction box and mount that on the Bandsaw. Have the 110 cord coming into the junction box/VFD with an external 110 switch to power VFD up. Then have the 220 3 phase cord coming from the VFD out of the junction box and into the motor. After that, I can run a signal wire to the machine's original on/off switch from the VFD.

So the ides here is to not have to see or actually touch the VFD. It will stay clean inside its enclosure. When I want to run the saw, I flip the AC 110 switch on the junction box to power the VFD, then the machines original power switch to start it up.

Don't start the motor using that switch down stream of the VFD. It's really hard on the transistors of the drive and will eventually fry them. The drive is meant to always ramp the motor from a start command given to the drive, not start it across-the-line. If you want to
Use that switch for convenience, just wire one pole of it as the low voltage run command to the drive. The instructions will be in the drive manual.

That was a very scary plug.

Also please not that it was wired up to the plug with three conductor wire. There was no grounding wire
connected at the plug. Good think you're going to trash out the old wiring and do it fresh!

Yes, will be redoing all the wiring. From the motor up.

I just gut the VFD Teco L510. The instructions supplied aren't very clear on wiring for the 110 input. It says to hook up the input power to L1(L) and L3(N). does the neutral get hooked up to L3(N)? I'm assuming "(N)" Stands for neutral and "(L)" stands for line in this instance?

Yes.

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Got the old Walker Turner running with the VFD. Thanks for the help guys.

Do you have a recommendation for a good bandsaw blade for cutting mild steel plate?