Wayne wrote:

I'm having a Leeson VFD (Model #174273, leeson.com) installed
on a lathe by the seller. It has 220v sgl phase in. I purchased
the VFD separately.

I know they have experience with VFD's. A service tech
working for a drive manufacturer was also there and helped
out. I don't think I clearly understood the issue, but here goes...
They tell me that the motor doesn't have any torque. They also said that
the VFD would need to know what gear range the lathe is in in order
to work properly. The motor is not a VFD rated motor. They are
uncomfortable selling the lathe with the VFD because of the
poor performance.


The first guess is the motor is still wired for 440 Volts, and needs to be
changed over for 220 V. Assuming the motor is a 220/440 V motor,
this should be easy to check, and easy to fix.

I assumed as long as I kept the VFD @ 60 hz, I could use the
gear ranges on the lathe as if it was hooked up to a normal
3 phase power line. Then I could make small speed adjustments.

I did ask if I bought a VFD rated motor if they thought this
would solve the issue. It sounded like it would help, but
still not work right.


Why the heck not? If a good motor, of correct voltage, RPM and HP
is installed, it HAS to work!

I'm getting Leeson to contact them.

I've done searches for VFD information in this NG before I
bought. I never heard of anyone having an issue like this.
Or having a motor that wouldn't work with a VFD.


Yup, I HAVE heard of this before. But, there was usually a reason
for it. Either the motor was set for the wrong voltage, was a dual-speed
motor or some other complication.

All I can say, is I have done this on a Sheldon 15" lathe, and it worked
like
a DREAM! In this case, it is a Tosvert A5 VFD, a pretty fancy unit, and
a bit larger than actually needed. I get variable speed, very slow jog for
getting gears to engage, and dynamic braking to stop the chuck like it
had a brake. Make sure you get braking resistors in your setup, it makes
a real difference on a lathe.

Anyway, I can't explain the problem, but I'm pretty sure they are doing
SOMETHING wrong, there. If the lathe has a dual speed motor, that
really complicates the wiring, and I can understand how they are getting
confused.

Jon

I'm having a Leeson VFD (Model #174273, leeson.com) installed
on a lathe by the seller. It has 220v sgl phase in. I purchased
the VFD separately.

I know they have experience with VFD's. A service tech
working for a drive manufacturer was also there and helped
out. I don't think I clearly understood the issue, but here goes...
They tell me that the motor doesn't have any torque. They also said that
the VFD would need to know what gear range the lathe is in in order
to work properly. The motor is not a VFD rated motor. They are
uncomfortable selling the lathe with the VFD because of the
poor performance.

I assumed as long as I kept the VFD @ 60 hz, I could use the
gear ranges on the lathe as if it was hooked up to a normal
3 phase power line. Then I could make small speed adjustments.

I did ask if I bought a VFD rated motor if they thought this
would solve the issue. It sounded like it would help, but
still not work right.

I'm getting Leeson to contact them.

I've done searches for VFD information in this NG before I
bought. I never heard of anyone having an issue like this.
Or having a motor that wouldn't work with a VFD.

I'm puzzled, anybody have any ideas?

Thanks,
Wayne

Something else is wrong, maybe with the VFD.

When the VFD is set at 60 hz., the motor should put out essentially the same
power as if it was running from "power company" 3 phase. If that's not
happening, something is fundamentally wrong with the motor, the VFD or the
way its hooked up or configured.

In my experience a "VFD rated motor" is not required. There's tons of people
running ordinary motors with VFD's with no problem, and I've never heard of
a specific problem traced to the use of a "non-VFD motor". If anyone had's
such a problem, please speak up.

Keep in mind you do lose significant power as you get away from 60 hz. on
the VFD. Depending on your motor, somewhere between 5 hz and 10 hz you go
down to zero power. On my 2HP (non-vfd) motor on my lathe, I get some usable
torque at 10 hz. so thats the lowest speed I allow. I don't do any heavy
cutting at that speed but its useful for tapping, in fact I like the limited
torque for that usage. At 30 hz. you'll be a little less than half power.

Also as you go up in speed over 60 hz. you lose power. At double speed (120
hz.) I believe you're down to about 1/3 full power.

I do mostly prototype work and small run production work, so I'm not pushing
my machines to the max. So for both my lathe and mill, the 2HP motor through
the VFD gives me plenty of power running my VFD from 10 hz. to 120 hz.,
although most of the time I'm in the range of 30 hz. to 90 hz. I hardly
every change the belt position on the mill and I usually only go in the back
gears on the lathe when tapping.

However, if you have jobs where you need to run the motor for a long time at
lower speeds with some load on it, you need to put an extra fan on it. Most
people get a 6" "pancake" fan and tie wrap it or wire it on the end of the
motor. If you want to get fancy, put a thermal "snap" switch on it so it
only turns on when the motor gets hot.

I haven't even bothered to do that yet since most of my low speed work is
one offs.

So find out if the machine seems to be putting full power out with the VFD
set at 60 hz., if not, something fundamental is wrong with the VFD, the
motor or the machine itself.

Good luck-

Paul T.

Make sure you get braking resistors in your setup, it makes
a real difference on a lathe.

Jon is dead on with this suggestion, the braking resistors work great on
both my lathe and mill. I never touch the brake on the mill anymore except
to change tooling.

Paul T.

"Paul T." wrote in message
...
Something else is wrong, maybe with the VFD.

When the VFD is set at 60 hz., the motor should put out essentially the
same
power as if it was running from "power company" 3 phase. If that's not
happening, something is fundamentally wrong with the motor, the VFD or the
way its hooked up or configured.

In my experience a "VFD rated motor" is not required. There's tons of
people
running ordinary motors with VFD's with no problem, and I've never heard
of
a specific problem traced to the use of a "non-VFD motor". If anyone had's
such a problem, please speak up.
No personal experience of problems, but the reason why VFD rated motors are
specified is that the high frequency switching waveform used in the VFD
causes high voltage spikes to appear on the motor as a result of the high
dV/dT and the motor's inductance; this can destroy the insulation on a
non-VFD rated motor. Aside from the insulation, there should be little or no
difference in performance.
Martin.
--
martindot herewhybrowat herentlworlddot herecom

Keep in mind you do lose significant power as you get away from 60 hz. on
the VFD. Depending on your motor, somewhere between 5 hz and 10 hz you go
down to zero power. On my 2HP (non-vfd) motor on my lathe, I get some
usable
torque at 10 hz. so thats the lowest speed I allow. I don't do any heavy
cutting at that speed but its useful for tapping, in fact I like the
limited
torque for that usage. At 30 hz. you'll be a little less than half power.

Also as you go up in speed over 60 hz. you lose power. At double speed
(120
hz.) I believe you're down to about 1/3 full power.

I do mostly prototype work and small run production work, so I'm not
pushing
my machines to the max. So for both my lathe and mill, the 2HP motor
through
the VFD gives me plenty of power running my VFD from 10 hz. to 120 hz.,
although most of the time I'm in the range of 30 hz. to 90 hz. I hardly
every change the belt position on the mill and I usually only go in the
back
gears on the lathe when tapping.

However, if you have jobs where you need to run the motor for a long time
at
lower speeds with some load on it, you need to put an extra fan on it.
Most
people get a 6" "pancake" fan and tie wrap it or wire it on the end of the
motor. If you want to get fancy, put a thermal "snap" switch on it so it
only turns on when the motor gets hot.

I haven't even bothered to do that yet since most of my low speed work is
one offs.

So find out if the machine seems to be putting full power out with the VFD
set at 60 hz., if not, something fundamental is wrong with the VFD, the
motor or the machine itself.

Good luck-

Paul T.

In my experience a "VFD rated motor" is not required. There's tons of
people
running ordinary motors with VFD's with no problem, and I've never heard
of
a specific problem traced to the use of a "non-VFD motor". If anyone
had's
such a problem, please speak up.
No personal experience of problems, but the reason why VFD rated motors
are
specified is that the high frequency switching waveform used in the VFD
causes high voltage spikes to appear on the motor as a result of the high
dV/dT and the motor's inductance; this can destroy the insulation on a
non-VFD rated motor. Aside from the insulation, there should be little or
no
difference in performance.
Martin.

I concur with Martin from personal experience. At work we fried a few
motors and traced the problem back to being non-rated motors for VFD use.
In working with the motor reps he confirmed that insulation is the
difference. The motors that we fried were running 24x7 and would only last
a month or two before failing so in limited machine tool use it should not
be a problem.
lg
no neat sig line

what they are telling you makes no sense. if the motor is a 3 phase 220V
motor, AND you hook it correctly to a VFD, AND you plug the VFD into 220,
the motor ought to work properly. There is no reason why the VFD need to
know gear ratio unless you expect the VFD display to read out in RPM. as
others have said, a VFD will drive pretty much any 3 phase motor, and in
home use, there seems to be no problem. You are getting the run-around.

"Wayne" wrote in message
om...
I'm having a Leeson VFD (Model #174273, leeson.com) installed
on a lathe by the seller. It has 220v sgl phase in. I purchased
the VFD separately.

I know they have experience with VFD's. A service tech
working for a drive manufacturer was also there and helped
out. I don't think I clearly understood the issue, but here goes...
They tell me that the motor doesn't have any torque. They also said that
the VFD would need to know what gear range the lathe is in in order
to work properly. The motor is not a VFD rated motor. They are
uncomfortable selling the lathe with the VFD because of the
poor performance.

I assumed as long as I kept the VFD @ 60 hz, I could use the
gear ranges on the lathe as if it was hooked up to a normal
3 phase power line. Then I could make small speed adjustments.

I did ask if I bought a VFD rated motor if they thought this
would solve the issue. It sounded like it would help, but
still not work right.

I'm getting Leeson to contact them.

I've done searches for VFD information in this NG before I
bought. I never heard of anyone having an issue like this.
Or having a motor that wouldn't work with a VFD.

I'm puzzled, anybody have any ideas?

Thanks,
Wayne

I have had a vfd on my lathe 15x40 lathe and my mill for at least 10
years.Single phase in 3 phase out. And I have never had a proplem with it . I
have never had a problem with torque.In fact I rarely change gears I keep my
lathe in high gear.I have the vfd set for 0 to 120 hertz.that will give me a
speed range from 0 rpm to 2400 rpm.But I usually
don't go past 60 hertz (1200 rpm).I can drill a hole at 1000rpm and turn the
speed knob
to 80 rpm and tap a 1/2 -13 thread in high gear.
I have been reading this news group every day for many years and I never heard
of someone losing a motor to a vfd.

On Wed, 09 Jun 2004 02:24:54 GMT, "william_b_noble"
wrote:

I'm having a Leeson VFD (Model #174273, leeson.com) installed
on a lathe by the seller. It has 220v sgl phase in. I purchased
the VFD separately.


I suspect I see the problem......

Gunner

"A vote for Kerry is a de facto vote for bin Laden."
Strider

In article ,
larry g wrote:
.......
difference. The motors that we fried were running 24x7 and would only last
a month or two before failing so in limited machine tool use it should not
be a problem.

I am curious; What voltage were these motor running on??
Someone reported that normal 230V motors seem to hold up well running
from a VFD, but higher voltage motors do not. So I am curious
if your failures support of disprove this theory.
chuck

what they are telling you makes no sense.

Well I'm not so sure.
Here is a similar personal experince.

I installed a 2HP Teco VFD on a rockwell 11x25 lathe with a 1HP rockwell
motor. This lathe also had a mechanical variable speed drive.
With the stock motor it would not start if the mechanical VS
was set above 800RPM. The motor simply did not have enough torque
to overcome the drag and inertia of the VS drive and spindle.
I changed some parameters in the VFD to increase the starting torque
and made it work pretty well. The caveat is that the motor would
probably burn out if operated at low speed with the amount
of low RPM torque boost I programmed in.

I have sense changed the motor to a 2HP Leeson inverter duty motor
and it runs extreamly well without any torque boost. I also
replaced all bearings on both jackshafts because they were dry.
This may have been part of the original problem.

I now have two leeson inverter duty motors and I believe they
are an excellent value. I paid 150 for a 2HP inverter duty
motor from an on line supplier. electric motor warehouse
or something like that.

chuck

Hmmmm...now that brings up a question. If the VFD is set in a soft
start mode and the gearbox on the lathe is engaged you are essentially
starting the motor loaded at the low end of the HZ range which means
little to no torque. I would anticipate the thing wouldn't get going or
would have problems getting past the low speeds. (assuming the VFD is
used as the starting device rather than just providing 3 phase to the
machine)

Can't remember the exact details of the original question though.

Someone said here that a two speed motor would NOT work with a VFD. Not
being all that good with motor electrics, I was wondering why this was.
I was under the impression that 2 speed 3 phase motors simply energised
the poles in the motor differently to achieve the second speed. My
lathe has a 5 HP 2 speed and it would be nice to run it off the VFD
simply because my current rotary convertor won't run it well on the low
range (hates to start). It would be very difficult to change out the
motor in this one and I don't have time to monkey around with it anyway.

Koz

Charles A. Sherwood wrote:

what they are telling you makes no sense.



Well I'm not so sure.
Here is a similar personal experince.

I installed a 2HP Teco VFD on a rockwell 11x25 lathe with a 1HP rockwell
motor. This lathe also had a mechanical variable speed drive.
With the stock motor it would not start if the mechanical VS
was set above 800RPM. The motor simply did not have enough torque
to overcome the drag and inertia of the VS drive and spindle.
I changed some parameters in the VFD to increase the starting torque
and made it work pretty well. The caveat is that the motor would
probably burn out if operated at low speed with the amount
of low RPM torque boost I programmed in.

I have sense changed the motor to a 2HP Leeson inverter duty motor
and it runs extreamly well without any torque boost. I also
replaced all bearings on both jackshafts because they were dry.
This may have been part of the original problem.

I now have two leeson inverter duty motors and I believe they
are an excellent value. I paid 150 for a 2HP inverter duty
motor from an on line supplier. electric motor warehouse
or something like that.

chuck

On Wed, 09 Jun 2004 07:05:44 GMT, Gunner wrote:

On Wed, 09 Jun 2004 02:24:54 GMT, "william_b_noble"
wrote:

I'm having a Leeson VFD (Model #174273, leeson.com) installed
on a lathe by the seller. It has 220v sgl phase in. I purchased
the VFD separately.


I suspect I see the problem......

Gunner

Ooops...sorry..I was over tired and misread it. Disregard

Gunner

"A vote for Kerry is a de facto vote for bin Laden."
Strider

The reason motors running on 230 are more resistant to voltage spikes is
that they are usually rated 230/460V and the insulation system is actually
good for 600V. At least that is the case on quality Nema frame motors.
Running at 230 gives a lot more safety margin to supply voltage spikes.

Randy

"Charles A. Sherwood" wrote in message
...
In article ,
larry g wrote:
......
difference. The motors that we fried were running 24x7 and would only
last
a month or two before failing so in limited machine tool use it should
not
be a problem.

I am curious; What voltage were these motor running on??
Someone reported that normal 230V motors seem to hold up well running
from a VFD, but higher voltage motors do not. So I am curious
if your failures support of disprove this theory.
chuck

I believe the original poster stated that he was trying to use a VFD with a
SINGLE phase motor. That doesn't work. Most of the replies refered to THREE
phase motors and their remarks are applical to that.

Earle Rich
Mont Vernon, NH

In article , Gunner says...

I'm having a Leeson VFD (Model #174273, leeson.com) installed
on a lathe by the seller. It has 220v sgl phase in. I purchased
the VFD separately.

I suspect I see the problem......

The abbreviations were confusing, at first I also took
that to read he had a single phase motor in the lathe.
But I think he really means that the VFD he purchased
is designed to run on 220 volt single phase in(put)
power source.

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

In article ,
Koz wrote:

[ ... ]

Someone said here that a two speed motor would NOT work with a VFD. Not
being all that good with motor electrics, I was wondering why this was.
I was under the impression that 2 speed 3 phase motors simply energised
the poles in the motor differently to achieve the second speed. My
lathe has a 5 HP 2 speed and it would be nice to run it off the VFD
simply because my current rotary convertor won't run it well on the low
range (hates to start). It would be very difficult to change out the
motor in this one and I don't have time to monkey around with it anyway.

[ ... lots of HTML snipped from bottom of article ... ]

O.K. My *opinion* on this is that the two-speed motors require
switching the windings. VFDs should *not* be switched between the VFD
and the motor, or you risk damaging the output transistors with voltage
spikes. Normal practice is to ask the VFD to stop or start the motor.

As far as I can see -- a two-speed motor should work fine with a
VFD as long as you *always* remember to stop the motor with the VFD,
switch the speeds, and then restart, so you are not switching an
electrically-hot motor. The problem here is in *always* remembering to
not switch the motor speed while it is running from the VFD. (Note that
I am switching a 1HP motor being run from a 7-1/2 HP VFD, so with
sufficient over-capacity, it seems to work, even for plug reversing.

As for two-speed motors with the so-called static converters,
such as Phase-o-Matic -- those are designed for a specific horsepower
range to start the motor. Too large or too small a horsepower, and a
given converter won't work. Since the switching of the windings changes
the horsepower (by a factor of two, IIRC), switching the speed would
produce a motor which would not start with the static converter, thus
problems there, too.

A good healthy rotary converter should handle the two-speed motor
with no problems, and no need to remember to always stop the motor
*before* switching the speed.

Enjoy,
DoN.
--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

In article ,
ERich10983 wrote:
I believe the original poster stated that he was trying to use a VFD with a
SINGLE phase motor. That doesn't work. Most of the replies refered to THREE
phase motors and their remarks are applical to that.

What he said was (cut and pasted from the original article):


================================================== ====================
I'm having a Leeson VFD (Model #174273, leeson.com) installed
on a lathe by the seller. It has 220v sgl phase in. I purchased
the VFD separately.
================================================== ====================

If the "It has 220v single phase in." applies to the lathe, then
yes, he has the problem which you have spotted. Agreed that a
single-phase motor will not work with the output of a VFD unless it is
kept at 60 Hz.

The real question is whether that was supposed to apply to the
motor (and lathe), or the VFD. I assumed that it applied to the VFD, as
did most of the rest of us. Careful sentence construction is more the
exception than the rule here, I fear, so we'll have to see.

If the motor is a single-phase one, then why did he buy a VFD
in the first place?

Enjoy,
DoN.
--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

Koz wrote in message ...


snipped...

Someone said here that a two speed motor would NOT work with a VFD. Not
being all that good with motor electrics, I was wondering why this was.
I was under the impression that 2 speed 3 phase motors simply energised
the poles in the motor differently to achieve the second speed. My
lathe has a 5 HP 2 speed and it would be nice to run it off the VFD
simply because my current rotary convertor won't run it well on the low
range (hates to start). It would be very difficult to change out the
motor in this one and I don't have time to monkey around with it anyway.

Koz

Charles A. Sherwood wrote:


--

I have an inverter driving a two speed motor.
Works GREAT!
From .5 to 180 Hz.

What could possibly be the problem?

Pete

The VFD is single phase in, 3 phase out. The motor
is 3 phase. To my knowledge the motor is a single speed.
I passed on the suggestions that I picked up from you guys.
I also learned a few things that I didn't know.

They are interested in selling the VFD as an option.
I'm the prototype customer because I wanted the VFD.
(See what happens when you read the newsgroup and everyone
likes the VFD's!)

After they explained the problems to me, they 1st offered
to return my check and my VFD. Good guys. I let them know
I'll buy the lathe even if the VFD doesn't work out.

An expert from Leeson and an expert from the lathe place
were supposed to get together today to discuss it. I didn't
hear back yet, so it probably didn't happen today as planned.
I'm just going to wait until they figure out what is going on.

I'll post back when they respond.
Thanks all!

So here is what happened. A visiting 'expert' was working on
some other equipment at the shop where I'm buying the lathe from.
He convinced the technician who works at the shop that the VFD
wouldn't work properly. He's the one that said you have to have
equipment to sense what gear ratio the lathe is in. He also
claimed you wouldn't be able to thread with a VFD connected to the
lathe. I know this is done with gear ratios and from the post by tlkallam8
that he does it all the time, that this wouldn't be true.
Apparently the lathe was never run with the VFD.
So the lathe is going to get shipped this week, and I'll have it
next week. I'll be connecting the VFD myself.
So the problem was just miscommunication.

Thanks for all your input.
Wayne

(Wayne) wrote in message . com...
The VFD is single phase in, 3 phase out. The motor
is 3 phase. To my knowledge the motor is a single speed.
I passed on the suggestions that I picked up from you guys.
I also learned a few things that I didn't know.

They are interested in selling the VFD as an option.
I'm the prototype customer because I wanted the VFD.
(See what happens when you read the newsgroup and everyone
likes the VFD's!)

After they explained the problems to me, they 1st offered
to return my check and my VFD. Good guys. I let them know
I'll buy the lathe even if the VFD doesn't work out.

An expert from Leeson and an expert from the lathe place
were supposed to get together today to discuss it. I didn't
hear back yet, so it probably didn't happen today as planned.
I'm just going to wait until they figure out what is going on.

I'll post back when they respond.
Thanks all!