I have a Clausing 2276 drill press from the late sixties. It has a Reuland two speed, reversible motor. A beastly heavy looking one. It is three phase and I am trying to install a vfd to bring it down to 220v single phase. I have contacted Reuland trying to get a wiring diagram. No success yet, but they seem hesitant to let me run it on a vfd. Does anyone know how to hook up a two speed motor to a Hitachi drive (output options of U/T1, V/T2, W/T3)? Is it an iffy idea to run such an old motor on a drive? Would it immediately fail, or is that a long term fire hazard? Thanks in advance
1966 Clausing Drill Press VFD Help?
- Thread starter bjc4073
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marinusdees
Well-known member
A motor that old is not rated to run on a VFD. That being said, the consequences come when running at slow speeds, the motor overheats. Takes a while, depends on the load. For home/hobby use probably not a problem. I have three phase motors on drill presses and a round column mill which are not inverter rated, but I have used them for years on VFDs intermittently with zero problems. You say bring the voltage down to 240. If the motor is 380 or some higher voltage, I don't think it can be adapted to run on a lower voltage short of a transformer, theoretically possible but not practical. I would think you could wire to the higher speed windings only and use the VFD to control speed. You need a VFD rated to the horsepower of the motor. To run on single phase, the VFD must be overrated, can't remember the percentage over. Maybe 50%?
Some pictures would be nice.
If there's a motor repair shop near by, the resident pro should be willing to answer some questions, maybe a bribe??
Some pictures would be nice.
If there's a motor repair shop near by, the resident pro should be willing to answer some questions, maybe a bribe??
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marinusdees
Well-known member
Typically, three phase motors require three hot leads, one for each phase. Typically, VFDs have three outputs, one for each phase. Of course, you need a ground wire. Your VFD will have two inputs, one for each leg of the 240. I am not familiar enough with three phase motors to recognize how a two speed works or is wired. I am certain what you want to do is possible, but without a look at the motor wires, I can't even venture a guess.
What you want to do is, I think, do-able. Reuland is reluctant to give their blessing mostly because of the overheating problem, I think.
What you want to do is, I think, do-able. Reuland is reluctant to give their blessing mostly because of the overheating problem, I think.
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lafester
Well-known member
All you need to do is get a VFD that is rated for the HP of your motor.
Not sure how the motor speeds work but that should not be a factor.
I have run old motors with no issues at all.
Oh, and you can't really screw up the wiring. Take the 3 wires and hook them up to the vfd output... if it runs backwards switch any two wires and you are done. This is assuming your motor doesn't have some weird wiring setup.
Not sure how the motor speeds work but that should not be a factor.
I have run old motors with no issues at all.
Oh, and you can't really screw up the wiring. Take the 3 wires and hook them up to the vfd output... if it runs backwards switch any two wires and you are done. This is assuming your motor doesn't have some weird wiring setup.
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tool_scrounge
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It is a two speed motor, it will probably be weird wiring.
tool_scrounge
Well-known member
I am sure you already know this, but be sure to have the motor windings (whichever set you are going to use) wired directly to the VFD output. No switches or contactors in between.
DocsMachine
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[cracks knuckles]
-Okay, as Scrounge notes, you're not supposed to have any switches or breakers between the VFD and the motor. Switching a VFD output under load can blow out the electronics- newer VFDs are supposed to be more resistant, but you're still not supposed to do it.
Now, that said, I have an Arboga gear-head drill press, that has a built-in 2-speed motor. It originally came wired for native 3-phase, and so had a rotary switch: hi-off-low.
As I was going to run it off a VFD, what I did was repurpose the original switch and mount it in the side of the casting. It still works the same way, but using the VFD feed.
Since I am the only one that will ever be using it, I simply make sure the VFD is off (that is, not currently powering the motor, not, like, "powered down" off) before I switch from high to low or vice-versa.
I then have some low-voltage buttons on the front of the machine for conventional start/stop, controlling the VFD itself.
An alternative is, as suggested above, to wire just one of the windings sets, and simply always run the drill on either high speed (say, for woodworking) or low speed (for metalworking.)
Keeping in mind that a good VFD can indeed slow down a fast setting, but at the same time you lose HP as fast as you lose RPM. And trying to turn a big drill in steel needs to be very slow AND have lots of torque. You won't get that just letting the VFD slow the motor down.
AND... something I just learned on a lathe I've been working on, there are in fact 2-speed motors that cannot be run- at least not well, or for long- on just one 'winding'.
My lathe has a 2-speed that's apparently called a "concurrent pole" motor- as I understand it (and my understanding is thin
) it's something like wiring it in wye gets one speed, and wiring it in delta gets the other speed.
And in one or the other, two fields, I think, need to be shorted.
That setup pretty much had to be run on native 3-phase, no VFD was going to do the job, without some seriously fancy wiring, plus relays and whatnot. As it was, just wiring the correct style of breakers took no small bit of doin'.
So yes, I'd say you need to dig up a proper diagram for that motor, and make sure that you actually can run it off a VFD.
Or grab/build a small rotary converter and feed it proper(ish) 3-phase. That's what I had to do for my lathe.
Doc.
-Okay, as Scrounge notes, you're not supposed to have any switches or breakers between the VFD and the motor. Switching a VFD output under load can blow out the electronics- newer VFDs are supposed to be more resistant, but you're still not supposed to do it.
Now, that said, I have an Arboga gear-head drill press, that has a built-in 2-speed motor. It originally came wired for native 3-phase, and so had a rotary switch: hi-off-low.
As I was going to run it off a VFD, what I did was repurpose the original switch and mount it in the side of the casting. It still works the same way, but using the VFD feed.
Since I am the only one that will ever be using it, I simply make sure the VFD is off (that is, not currently powering the motor, not, like, "powered down" off) before I switch from high to low or vice-versa.
I then have some low-voltage buttons on the front of the machine for conventional start/stop, controlling the VFD itself.
An alternative is, as suggested above, to wire just one of the windings sets, and simply always run the drill on either high speed (say, for woodworking) or low speed (for metalworking.)
Keeping in mind that a good VFD can indeed slow down a fast setting, but at the same time you lose HP as fast as you lose RPM. And trying to turn a big drill in steel needs to be very slow AND have lots of torque. You won't get that just letting the VFD slow the motor down.
AND... something I just learned on a lathe I've been working on, there are in fact 2-speed motors that cannot be run- at least not well, or for long- on just one 'winding'.
My lathe has a 2-speed that's apparently called a "concurrent pole" motor- as I understand it (and my understanding is thin
) it's something like wiring it in wye gets one speed, and wiring it in delta gets the other speed.And in one or the other, two fields, I think, need to be shorted.
That setup pretty much had to be run on native 3-phase, no VFD was going to do the job, without some seriously fancy wiring, plus relays and whatnot. As it was, just wiring the correct style of breakers took no small bit of doin'.
So yes, I'd say you need to dig up a proper diagram for that motor, and make sure that you actually can run it off a VFD.
Or grab/build a small rotary converter and feed it proper(ish) 3-phase. That's what I had to do for my lathe.
Doc.
DocsMachine
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-Except for the fact you lose 2/3rds of your HP along with 2/3rds of your RPM. And on a drill press, slower speeds are usually reserved for big drills and/or harder materials like steel.
Doc.
tool_scrounge
Well-known member
[cracks knuckles]
Or grab/build a small rotary converter and feed it proper(ish) 3-phase. That's what I had to do for my lathe.
Doc.
This is probably the best advise for a two speed motor. They are not hard to build.
What is the motor hp? Mine is 1 hp and I wired the vfd off the motor lead bypassing all other controls.
Just hook up your VFD, it will work fine. The mechanical switching with your 2 speed motor won't negatively effect the VFD ( I'm imagining it's some form of a rotary switch with multiple contacts.) However if you have motor controls with fuses, heaters, breakers, etc, they should be bypassed.
lafester
Well-known member
Has anyone experienced losing 2/3rds hp with 2/3rds less rpm?
I have not and I have 3 vfd setups going. I do have them running on Reeves drive machines so I can still run at a moderate frequency, but my first one was on a single pulley drill press setup. 3/4 hp motor never stalled on any speed.
I have not and I have 3 vfd setups going. I do have them running on Reeves drive machines so I can still run at a moderate frequency, but my first one was on a single pulley drill press setup. 3/4 hp motor never stalled on any speed.
You're not loosing anything. You have full speed control with the vfd. Motor has less horsepower in low speed than it does in high-speed anyway. Generally they produce the same torque at both speeds. A vfd will do the same thing.
Yes, Yes it will. If that switch gets changed anytime the vfd is running it's very hard on it. Do it repeatedly and you're going to get to buy a new vfd.
If you could design it so that the rotary switch has a contact that turns off the vfd before switching the motor then it would be ok. I imagine that would not be an easy thing to find.
Roberts210
Well-known member
Horsepower is a function of torque and RPM. The lower the RPM, the lower the H.P. Higher the RPM, the higher the H.P.
Internet myth. Not true. I've run multiple VFD's in combination with mechanical switches of various types for years. No problems. Forward/reverse drum switches, E stops, and others. But if there are heaters, overloads, etc, they will pose problems like false tripping and should be bypassed.
DocsMachine
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Absolutely not a myth. Read the manual that comes with the VFD. All mine have it in big, bold lettering that you should NOT have any contactors, breakers or switches between the VFD and the motor. Doing so damages the VFD and voids the warranty.
Doc.
Doc.
I apologize for missing a few days of replies. Thank you all for the help. Dreamer- yes, but I don't have power feed. I wired it up (without switches in line), a little bit of tuning, and I'm off to the races with an industrial press for a lot less than a new Jet. Between the (working) Reeves drive and vfd, there is a lot of adjustment, but I will leave the vfd at full and work the reeves first to try and simulate it's original design and maximize torque.