Do we have any members that have done a VFD conversion on an XLO 602 Milling machine?

So far everything has gone pretty smooth on my 602. I cleaned the machine up a little bit and removed some surface rust here and there. Overall, the machine is in pretty good shape for it's age. I did verify the machine worked prior to purchasing it.

In my shop, I will be using a VFD. I should mention I have never wired a VFD to a milling machine. All of my experience lies with lathes. My intention was to just bypass the forward/reverse switch and grab the three main leads from the motor and bam, I'm in business. The problem came when I pulled the motor cover off and saw six wires, which I haven't seen before on any three phase motors I've done in the past. This makes me wonder if my motor is a two speed, or if those three additional wires might possibly run to the power feed (whose motor has long since been removed) but that doesn't make much sense since they are being pig-tailed into the forward/reverse switch with the main motor. I can't seem to locate a manual to identify which wire is which, but they are numbered.

Now, it's important to disclose that each of these two wires are pig-tailed into the three load wires to the main power, so whatever they are, they are both getting standard 3-phase power. I'm sure it's probably something simple, so I'd love it if anyone had some suggestions for me.

My last question is regarding the vari-speed drive. I've never dealt with one of these pulley speed controllers before. It would seem the best solution would be to use a 1:1 drive pulley on the spindle, but I'm still rebuilding my lathe. In the meantime, is it acceptable to just run the main motor flat out (I assure this would be as it was designed) and utilize the vari-speed drive for the time being?

See attached photo for reference.



The wires are bundled in the follow order:

1/7
2/8
3/9

The three black conductors all go to the forward/reverse switch as you would expect.

There are three wires all pigtailed together:
4/5/6

Any help is greatly appreciated!

I would guess that the motor can be wired for 220 or 440 volts and the pigtails are rearranged to switch between the two. If your VFD output is 220 and the motor previously ran on 220, just wire from the VFD as you would if you were putting a new cord on it.

It's probably in your instruction manual, but if you're not following that be sure to bypass the forward/reverse switch and do the direction change from the VFD controls.

That makes sense because the data tag does say 220/440. I'm guessing the two sets of wires and the different numbering is how to identify them. Problem is, I cannot find a wiring diagram. What would the typical wiring scheme be? Both wires as they are configured in the photo? Or should I choose a set and give it a shot? I just don't want to damage anything like the idiot who wired up my lathe before me.

Thank for the info, I did mention above I was bypassing the switch. I'm using I/O and a pendant to control the VFD, so no worries there.

It sounds like you have a nine-lead motor, wired for low-voltage wye (see figure 5.19.

You should be able to just leave it as is and connect the VFD to the three leads going to the drum switch.

The motor nameplate should have more details, but this is almost certainly how to power it for 230V.

Thanks for the insight. Here is the data tag, if that's any help.



So, wire the VFD into the same configuration as above, with both leads going to one conductor?

Yup. As long as it's still a 230V supply to the motor, the wiring doesn't change.

Does anyone have any thoughts on running a vfd with a vari-speed?

It's not going to help with the motor wiring, but here's a manual.

http://manuals.chudov.com/Excello-602-Mill-Manual.pdf

Lots of people use VFDs with Reeve's Drives including me. No reason for it to be a problem. Leave the VFD at 60 Hz and adjust the speed with the belt. You'll get more torque that way. My Reeve's Drive is jacked up, so I use the speeds it runs the smoothest at and fine tune with the VFD.

Thanks so much for the reassurance. I'll run it long enough to machine some timing belts.

I found this video link useful to help visualize the motor connections.
YouTube

-D

Welp, finished my wiring and input my motor settings and I've got some sort of problem. I keep hitting overload protection on the VFD. The motor starts to whine, barely twitches a few times (I can see the spindle slowly turn) then it hits overload. It honestly feels like it's incredibly underpowered, but my vfd is matched to my motor. Seems like it's at like 10% power. Any ideas? Wondering if it's my motor wiring. It seems like the motor may be wired for 440 and not 220. Do we have anyone that can look at my wire grouping above and let me know if that's my problem?

Hold the phone. I learned why you're not suppose to turn the speed dials when the machine is off. Must had had a binding belt in the head. Fires up like a beauty now. Beer time boys.