# Vfd info



## Lordbeezer (Jun 25, 2017)

Picked up a Lear Siegler inc vfd..model VS225..new in box..wiring diagram approved in 63..shows 115v input..output field and arm ..guessing this is for dc motor?? Would it work for permanent magnet dc.? Thanks for looking


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## markba633csi (Jun 25, 2017)

It's a variac type control and probably for a motor rated less than 1/4 HP.  For a power feed or some similar usage it would be fine, but
for a lathe I'm not sure.
Mark S.
ps is there a circuit board over on the right side? Can we see a picture of that? I don't see any rectifier 
diodes in there


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## tq60 (Jun 25, 2017)

Looking at what we can read on a phone of the schematic, it has connections for both field and armature.

So it seems this was to control a non - inductive motor rather one with a commutator or brushes as it is expecting an armature with a set of windings.

A universal motor fits this bill but the overall size of the device supports estimating a small motor.

Look for a fuse some place or a nomenclature tag indicating capacity in hp or current. 

If only a fuse can be found then take 1/2 that value in amps and multiply by the listed 115 volts to get watts then divide that by 745 to get hp rating.

Sent from my SAMSUNG-SGH-I337Z using Tapatalk


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## Lordbeezer (Jun 25, 2017)

Don't see a circuit board..fuse on lid has no numbers.fuse inside is 250 v..buss acc 1..is this for ac or dc  motor. Thanks for your time


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## hman (Jun 25, 2017)

Just for fun, I did a little playing with the image of the schematic ...


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## Lordbeezer (Jun 25, 2017)

Been doing the goggle thing..still don't know if this for small ac or dc motor.hate to burn it up trying motors..thanks


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## hman (Jun 26, 2017)

Howzabout you plug it in, turn it to "forward," give the Variac about 1/10 of a turn, and check across either the "field" or "arm" terminals with a DVM - first set to DC volts, then to AC.  One or the other should give you a reading.  This will be safe enough for the controller and should at least get you started.


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## Lordbeezer (Jun 26, 2017)

Arm output..on dc voltage goes up as knob is turned smoothly up to 120 ..on ac very low kinda jumps around..field jumps around ac or dc doesn't go over 44 v. Thanks


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## tq60 (Jun 26, 2017)

Will assume fuse is on line input so 1 amp at 115 (op stated labeled voltage) then 115 watts maximum capacity but assuming some starting loads then assume motor size maybe 80 watts or maybe 1/10 hp.

Likely for a small sewing machine size motor.

Sent from my SAMSUNG-SGH-I337Z using Tapatalk


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## Lordbeezer (Jun 26, 2017)

Would you think this is for dc motor? Have a Baldor gear motor would like to use for power feed on enco 110 mill..thanks


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## f350ca (Jun 26, 2017)

That controller is for a DC motor. My Hardinge lathe uses the same design power supply for the DC carriage feed motor. It feeds full 110 volts to the fields and varies the armature voltage for speed control. With full field voltage the motor can produce more torque at slow speeds than ones that reduce both armature and field power. 
The field power should be steady, and I would expect 110 v.
I don't see what I would recognize as a rectifier in the picture or the circuit so it may be AC output.

Greg


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## markba633csi (Jun 26, 2017)

I didn't know there were controllers that vary the field.  But yes normally the field voltage should be steady.  Be a simple matter to add rectifiers to it though
then you could use it with a dc permanent magnet motor, or a shunt wound type with a field.  Can you post a picture of that Baldor motor you want to use?
Mark S.


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## 4GSR (Jun 26, 2017)

That varac xformer should be able to handle about 10 amps.  Those two blue round looking things are your SCR's.  There's also a fuse in the bottom of the box, according to the schematic is F2.  What is the amperage of it?  I suspect, this fuse is to the amature, which shoould be a higher amperage than the one on the front cover.  The one on the front cover is probably for the field winding.  One amp would be just about right on a fractional rated motor, probably not over 1/4 HP.  Of course, this is depended on the amp rating of the other fuse.  And , yes, you should be able to hook up a PM motor to this controller.  Just connect to the amerature connection only.  Leave the field connection open and not hooked up to anything.


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## markba633csi (Jun 26, 2017)

I don't know about 10 amps Ken, I was thinking more like 3; it doesn't look that big. But yes if those are SCRs then it can be used as is
Mark


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## ch2co (Jun 26, 2017)

for what its worth, my 2 cents worth
This is not a VFD (variable frequency device)
This was built before SCR (silicon controlled rectifiers) were in wide use
There appears to be something that looks like a full bridge rectifier in the light blue round thing with 4 attachments.
I don't think that the variac is capable of 10 amps
This device was manufactured before the postal zip codes were more than two numbers (before 1963)
I wouldn't trust the large electrolytic capacitor for being any good after all this time

Just thinkin which these days is getting harder and harder'

CHuck the grumpy old guy


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## woodchucker (Jun 26, 2017)

I was thinking SCR, I thought that they were that time frame.. I guess not.
was looking for the stacked set of disks, certainly not diode at that time.
Enough ranting, I don't have enough knowledge..


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## ch2co (Jun 26, 2017)

Corrections
OK SCR's were just getting started by '63 but there appears to be no such thing in the box. They were rather large (large peanut sized (without shell))
looking at the front panel, and the schematic, the blue disk is a 3 way switch not a rectifier bridge.

Grumpy old guy


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## chips&more (Jun 26, 2017)

Looks like a DC motor control to me. This control/supply has two DC outputs. One output is for the field (fixed DC). The other DC output is for the armature (variable). Those blue things are bridge rectifiers, CR1 & CR2. The smaller one is for the field and the bigger one is for the armature. That brown cylinder thing is probably an electrolytic capacitor. Sorry, it's not a VFD...Dave


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## 4GSR (Jun 26, 2017)

Bridge rectifiers!!! That's what I meant, not SCR's.  Thank you Dave.

Mark, yeah, variac is probably good for 3 amps! You are likely correct!

Used to use some about that size that would handle 10 amps.  Of course, that was on 240V.  Used them to power the field windings on BIG DC motors!  Even bigger one's for the field voltage voltage on the M-G sets.  Only did this because the owner didn't want to spend the extra $$$$ for SCR controlled motor controllers.  We ran motor-generator sets to run those big DC motors.

Getting too old for this stuff!


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## ch2co (Jun 26, 2017)

OK! the round blue thing is a rectifier bridge, not a switch, I looked at it and figured out that it was on the other side of the door that had a F-off-R switch on it 
switch on it and totally missed the point that the thing was on the back of the box, not the door. Duh.


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## markba633csi (Jun 26, 2017)

I think lordbeezer has gone to bed by now LOL
M


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## Lordbeezer (Jun 26, 2017)

Not in bed yet..just came in from building a pig cooker..controller will run 90v dc  Baldor gear motor.slow to faster..forward and reverse..but want to use it to run a bodine gear motor..115v dc..way it's wired now is not right .guess I have to separate wires field and arm..mark.would be real nice to use this on pm treadmill motor..add rectifiers??..big brown device in lower right corner looks like some sort of transformer.not Capisitor.thank y'all very much.phil..


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## Lordbeezer (Jun 26, 2017)

Why would company advertise this as a vfd if it's not a vfd. 1963 terminology??


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## Lordbeezer (Jun 26, 2017)

It does have a scbr..small blue disc at 2 o'clock to bigger blue cylinder. Thanks


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## markba633csi (Jun 26, 2017)

Who said it's a vfd? The place who you bought it from? It says "variable speed drive" on the front of it, not variable frequency.  Did you get this device at a garage sale?
Anyhow, it looks like the Bodine motor might work with it, I can't make out the current rating of the Baldor one.
The box still looks a bit small to run anything larger than about 1/10 horsepower
If the box is fused at 1 amp that would certainly be the case.
That small blue disc is the bridge rectifier (I recognize the Semtech name) and it looks pretty puny in terms of current rating.  I would guess it may be the limiting factor.
I would change it to at least a 10 amp, 400 volt unit.
Does the variac have any specs written on it?  That would probably the next limiting factor.
Mark S.
ps nice pig cooker


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## markba633csi (Jun 26, 2017)

On second thought the Bodine takes 3.3 amp, maybe not..
M


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## markba633csi (Jun 26, 2017)

Ken what does one need for a x axis power feed?  1/8 horse? 1/6?  
I'm afraid lordbeezer's box isn't going to cut it with either of the motors he has.
Mark


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## hman (Jun 27, 2017)

Lordbeezer said:


> ..big brown device in lower right corner looks like some sort of transformer.not Capisitor.thank y'all very much.phil..


That device looks like it might be a large inductor (ie, choke), to help smooth out the rectified DC.
PS - took another look at the schematic.  I noticed that there are + and - signs under the armature and field output terminals.  So it's definitely for DC motors, eh wot?


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## Lordbeezer (Jun 27, 2017)

Baldor draws 1.55 amps..1/7 hp...bought from a equipment co..guy said vfd and vsd.same thing..my dumb ass ...so if I replace the small blue rectifier it should hold up to the Baldor but not the bodine..thanks very much for your knowledge..Phil


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## whitmore (Jun 27, 2017)

f350ca said:


> That controller is for a DC motor....
> I don't see what I would recognize as a rectifier in the picture or the circuit so it may be AC output.


The "CR1" designation on the schematic is probably a bridge rectifier, and would make DC output likely.
So, it's a variable speed drive, VSD, not a VFD.   It's about the right size for a positioner or coil winder.

The box is labeled 'variable speed drive', NOT variable frequency


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## chips&more (Jun 27, 2017)

I just noticed a better pic of the schematic. And now see it does not have any capacitor(s) in the circuit. I do see a choke, L1, so that brown cylinder thing is probably the choke. Whatever DC motor you try to run with this VSD, note that some DC motors have a permanent magnet field and do not need a DC source for the field. In this situation you just supply DC to the armature and it can be fixed or variable voltage for variable speed.  And another note, the armature supply is typically of a higher current demand that the field current…Dave.


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## 4GSR (Jun 27, 2017)

Lordbeezer said:


> Baldor draws 1.55 amps..1/7 hp...bought from a equipment co..guy said vfd and vsd.same thing..my dumb ass ...so if I replace the small blue rectifier it should hold up to the Baldor but not the bodine..thanks very much for your knowledge..Phil


Leave the bridge rectifier alone.  Hook it up and see if it runs first.  It should handle  1.7 amps easily.  Change out the fuse with a 2 amp and don't look back.  Old electronics like this are generally oversized a bit for venturous guys like us to piddle with.  If it does blow, then put in a larger BRF in.  Otherwise, plug it in and giver her a try! What's the worse it's going to do?  Give off some magic smoke?  This is how you learn about old school electronics.


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## 4GSR (Jun 27, 2017)

markba633csi said:


> Ken what does one need for a x axis power feed?  1/8 horse? 1/6?
> I'm afraid lordbeezer's box isn't going to cut it with either of the motors he has.
> Mark


If you use one of them sub fractional HP gear motors, say 1/12 or 1/8 HP, probably work fine.  I'd rather spend the extra money and get one of those Severo-feed hook ups to use and not mess with anything else in my opinion.  It really doesn't take much torque to turn the crank on the mill to feed a end mill thru a cut.  Set up a beam type torque wrench that reads in in/lbs, attach on the nut on the feed screw and turn it to read the torque while feeding it thru a cut.  Then work off of that for sizing a gear motor.


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## markba633csi (Jun 27, 2017)

Agree totally with Ken as above.  Try a 2 amp fuse and don't look back. Baldor OK Bodine NO
The speed regulation will not be real good and the low speed torque will drop off somewhat
Also be careful since the box has no isolation transformer! Make sure you ground the box, and the motor.
Mark
ps Lear Siegler isn't that the same Lear that made Learjets?


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## ch2co (Jun 27, 2017)

Lordbeezer said:


> Why would company advertise this as a vfd if it's not a vfd. 1963 terminology??



Very Fine Device??


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## markba633csi (Jun 27, 2017)

very funny, dummy


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## Lordbeezer (Jun 27, 2017)

Ran the Baldor for awhile with the vSd..nothing got warm..ran 2.25hp 10amp 90v pm motor for about 15 minutes.different speeds.did ok with no load..very smooth. Thanks everyone for your helping me get a little knowledge on this stuff..going to pick up big press from guy that sold me the wanna be vfd..


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## 4GSR (Jun 28, 2017)

Until you put a load on the motor, you will not know if it will smoke or not.


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## Lordbeezer (Jun 28, 2017)

Heard that...probably gonna use the Baldor gear motor on mill power feed..just had to try the 10 amp motor..thanks


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