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3 phase motor experts please come on in

Earp69

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I picked up a leblond Makino a few months back, tested it under power and everything worked correctly and the lathe shifted through all the gears great. When tested the lathe was wired for 480. For my home application I needed the lathe to be wired 230 low voltage since I'm using a rotary phase converter, so I wired both the spindle motor, and hydraulic motor for the lathe according to nameplate. Now here is my issue, no matter what leads I swap I cannot get the hydraulic motor/pump combo to run the right direction. I have swapped 1-2,2-3,1-3 and the motor still runs the wrong direction which leaves my with a lathe that won't shift gears. I've been doing industrial electricity for 9 years now so this isn't anything new skill wise but I have never came across anything like this. I called leblond and they were baffled. I also hooked the motor up to my inverter where you can reverse rotation on the display, and the motor still won't reverse. I've had two people stop over just to triple check my wiring and they are just as baffled as me. Any help or suggestions is much appreciated. For the record I tried reversing the spindle motor just for shits and it reversed like it should by changing two leads.
 

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nadogail

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Identify the three phase supply lines to the motor (I like R, S & T) then disconnect two of them and reconnect as T, S, & R.
What you are doing is swapping two of the three phases.
 
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Earp69

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I'm swapping at the terminal strip where the supply lines go to the motor, the last termination spot in the panel. I've also switched "r, s, t" at the bottom of the motor starter for shits. I'm not swapping anything in the pecker head of the motor. Wouldnt swapping 123 for 321 in the panel the same as you swapping rst for tsr?edit just looked at the wiring and right now it's 3,2,1 or t, s, r. Also tried changing u, v, w for fun on the main incoming of the panel,not that it's logical but still no change.
 
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BillK

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Where are the leads at that you change for the different voltages ? That is where I would be doing the swap for the direction change. Almost all of my equipment is 3 phase and I have never had an issue like that.

Try calling the motor manufacturer ?

Not sure why it would make a difference but maybe try swapping two of the leads on the main power feed to the lathe ? That will switch the rotation on the spindle motor also but its worth a try.
 

Terry D

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I'm swapping at the terminal strip where the supply lines go to the motor, the last termination spot in the panel. I've also switched "r, s, t" at the bottom of the motor starter for shits. I'm not swapping anything in the pecker head of the motor. Wouldnt swapping 123 for 321 in the panel the same as you swapping rst for tsr?edit just looked at the wiring and right now it's 3,2,1 or t, s, r. Also tried changing u, v, w for fun on the main incoming of the panel,not that it's logical but still no change.
On the nine motor leads, you should have 4-5-6 tied to together. 1-7 together with a phase, 2-8 together with a phase and 3-9 together with a phase. swapping any two phases should change rotation.
 

loganb

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Can you provide a picture of the junction box of the leads coming out of the motor?

On a bandsaw I had bought out of Boeing the dual voltage motor had been rewound at one point in its life and they didn't pull the low voltage leads so although the nameplate said it was capable it wasn't anymore.
 
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Earp69

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I'm picking up what your putting down, thanks a lot makes sense now. Sounds Ludacris but I've never messed with anything low voltage yet all our stuff is 480.
 

Terry D

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I'm picking up what your putting down, thanks a lot makes sense now. Sounds Ludacris but I've never messed with anything low voltage yet all our stuff is 480.
Did you have it wired wrong? Is it rotating in the right direction now. As long as that diagram that you posted is off the actual motor, it should work. That diagram is for a Y wound motor. The only way it would wire different is if it was a Delta wound motor. I don't want to confuse things. As long as that diagram is off the motor in question, you should be good to go.
 
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sparky 1971

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Just a guess, but are you switching around 1, 2, and 3 of the motor leads? If so, put it back the way it's supposed to be and switch two of the phase wires. Leave 1-7, 2-8, and 3-9 tied together, each to a phase and leave them alone.
 
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Earp69

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Well I tried wiring it as you said, same dam way! Won't spin the other direction
 
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Earp69

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Did you have it wired wrong? Is it rotating in the right direction now. As long as that diagram that you posted is off the actual motor, it should work. That diagram is for a Y wound motor. The only way it would wire different is if it was a Delta wound motor. I don't want to confuse things. As long as that diagram is off the motor in question, you should be good to go.
Double post but I wired it as you said and it Still rotates ccw. And yes pictures posted are of actual motor
 

Walkers

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I spotted your problem. This motor is a 1/2 GF motor. That is a half a girlfriend power. Now this is nothin’ to mess around with. It is more powerful than a horse power, but it will go whatever damn direction it pleases, and if you insist it goes one way it will go the other. Very similar to a wifepower motor, but can provide a more enjoyable experience.

On a slightly more serious note, it is a half horse motor, why not just swap it for a single phase motor?
 

BillK

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Wyatt,
How about if you jumper some wires directly from your phase converter to the motor and see what happens ? That will eliminate anything in the rest of the lathe wiring, switches etc. I think you are overlooking something very simple but its hard to say without being there in person.
 

sparky 1971

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Just a guess, but are you switching around 1, 2, and 3 of the motor leads? If so, put it back the way it's supposed to be and switch two of the phase wires. Leave 1-7, 2-8, and 3-9 tied together, each to a phase and leave them alone.

Well I tried wiring it as you said, same dam way! Won't spin the other direction
If your reply was to my post, I apologize for leaving a part out, the wife was hollering at me that we had to go. If it's still spinning ccw, switch two phases. Swap phase A to 2-8 and switch phase B to 1-7. It should turn the other way. If it won't, then I am at a loss.
 
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MBfreak

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A long shot is that the motor has an open or disturbed circuit phase. Since you have tried everything else, it seems, I suggest the following:
Disconnect the motor from any power supply for the sake of safety.
Directly on the motor terminals connect the unit for the high voltage option.
Using a reliable ohm meter measure the resistance between two of the incomers at a time, ie three set of measurements.
It will take a little while for the ohm reading to stabilize due to the inductance in the motor windings. Be patient and do not spin the rotor.
Compare the three readings, they need to be equal to within a few %.

Best regards
Ola
 
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Earp69

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I spotted your problem. This motor is a 1/2 GF motor. That is a half a girlfriend power. Now this is nothin’ to mess around with. It is more powerful than a horse power, but it will go whatever damn direction it pleases, and if you insist it goes one way it will go the other. Very similar to a wifepower motor, but can provide a more enjoyable experience.

On a slightly more serious note, it is a half horse motor, why not just swap it for a single phase motor?
LOL, I enjoyed the humor but if i posted a picture you would see it's a motor/hydraulic pump assembly and they are made specific to eachother. Luckily it's now working though so we're good
 
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Earp69

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OK guys, tried everything but blow this thing up and had the same results. I went back and rewired everything how I had it from the get go 1-7,2-8,3-9. Now unless this is some kind of optical dam illusion the motor seems to still spin backwards according to the arrow on the pump. I tried shifting the lathe and it does shift so I'm not asking any questions and i buttoned the pecker head up.
 
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Earp69

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The only thing I can think, there is no fan on the motor so the only thing you can see spin for rotation verification is a small gear about 1.25" in diameter. It stops pretty abrubtly once turned off and the only thing I can think is it has some sort of kickback making the pump spin ccw once shutdown and that's the only part slow enough for me to visually see. I had two people also watch and they both thought it was turning ccw. I never tried shifting gears previously as I feared of messing something up with the valve body having the pump running backwards,but finally had enough and said f it I'm gonna try it. It shifted through all gears no issue numerous tkmes yesterday so I'm going to call this one licked. I wish I had a better explanation but no matter which way I changed the leads the motor still seemed to be running ccw once slowed down.
 

nadogail

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In order to see how a bare shaft spins when I "Bump" a motor, I often make a flag from tape and stick it on the shaft; I prefer masking tape because it is cheap, but any other kind of tape will serve.
 

htmdude57

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I'm not sure if the OP can put a tape flag on the gear that he says he can see turning. If it has some sort of "grill" made of slots, he could hold the pointy end of a tie wrap (zip tie) into the gear teeth to see (feel) which way the thing is turning.
 

pancho400cid

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ow unless this is some kind of optical dam illusion the motor seems to still spin backwards
so sounds like a case of mistaken visuals

It would not be the first time somebody got fooled by the exact optical illusion you're talking about.

One simple thing to try:

Touch something light and flexible (I often use thin zip-ties) against the fan, coupling, driven gear etc. kinda like playing cards in bicycle spokes LOL. The rotating part will force the zip tie in the direction of rotation.

I guess pressure could briefly back-spin the pump after shutting off the motor but it would have to stop and reverse first?

Lastly - and I hate to mention it, but sometimes driving backward will almost instantly destroy some hydraulic pumps. The safe approach is to de-couple the pump until you're SURE the motor is running in the right direction.

We recently went through this at work and killed a small lube pump with about a 1.5 HP, 3 phase motor driving it. We bitched to the equipment manufacturer that a prominent warning nameplate should have been put on the equipment. They shipped us a new pump without too much debate, and WE put a prominent nameplate on the equipment.
 
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