# Single phase to 3 phase conversion on Modern GH1440W lathe



## John Conroy (Mar 21, 2020)

I've been thinking about doing this since I got the new lathe a little over a year ago but a few things have happened lately to push me toward starting this project. First was the capacitor failure I experienced on the single phase motor that came with the lathe. Second, my wife and I got back from California on March 10 so we are in voluntary self isolation for a couple of weeks. Next was the link PeterT posted a while back to the Clough42 YouTube video series on installing a VFD. I've been shopping around for a used 3 phase motor but had no luck finding anything with a realistic price. I was going to buy another Huanyang VFD like the one I used for my mill but they have gone up in price since then and I didn't want to wait weeks to get one direct from China. With some web searching I found a company called Emotors Direct where I purchased a Teco-Westinghouse motor and compatable VFD online and picked up at the Edmonton Teco-Westinghouse warehouse the same day. I made arrangements with the warehouse people so I didn't have to get out of my truck during the pickup to maintain "social distancing". All the other components have been ordered from Amazon. The motor was priced lower than any of the used ones I found. The VFD was priced a little higher than a Huanyang but no de-rating is needed according to T-W. What that means is you can use a 3HP rated VFD on a 3HP motor. With Huanyang most people suggest going up 1HP on the VFD rating to be sure it can handle the current the motor requires, I bought a 4HP Huanyang VFD for my 3HP mill motor. The end result is I have a motor and VFD from the same manufacturer with 3 year warranty and no worry about the compatability of the 2 components. This project will probably a week or so and I will update here as I go.


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## David_R8 (Mar 21, 2020)

Watching as I’m looking to convert my mill to 3-phase. 


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## John Conroy (Mar 21, 2020)

By the way, I was pretty impressed with the service I got from Emotors Direct. I had problems completing the purchase online but the issue was easily corrected by phone and they offered a 10% discount on my first purchase which saved me $75.


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## David_R8 (Mar 21, 2020)

Thanks John, that’s the company of I’m looking at ordering from. 


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## John Conroy (Mar 21, 2020)

I learned quite a bit about motor frame sizes during my research. There are different standards for frame and shaft sizing, some use NEMA standards, some use  metric standards called IEC and some use a mixture of both. I learned that the single phase motor I have is one of the latter. The actual frame of the motor fits NEMA size standard 184T but the shaft is 28mm instead of 1-1/8". You can find all the dimensions for Nema or IEC motors online. The motor I bought has a 182T Nema frame . That means the width of the bolt pattern is the same as the old motor but the lengthwise dimension is 1" shorter. I could have bought a 184T motor with the same specs but the price was significantly higher so I elected to buy the 182T bolt pattern and drill/tap 2 holes for the rear motor hold down bolts. The motor mount plate on this lathe is amhuge chunk of cast iron so strength is not compromised. I used my welding table to help lay out the the hole patterns and to get the new 1-1/8" ID pulley aligned to match the old motor. The new pulley uses a split tapered bushing to mount to the shaft and the belt grooves are deeper to accomodate more than 1 belt size so I aligned the center of the new pulley with the old one.


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## John Conroy (Mar 21, 2020)

It took me a while to figure out a method to get the pulley aligned the same as the old motor. I put both motors side by side with bolts in the fŕont mount holes and used the protruding bolts to align them the same as if they were bolted to the mounting plate. I used a couple of 123 blocks aligned with the center web of both pulleys and làyed a straight edge across the leading edge of the blocks. It took a couple of trys because the pulley moves 


on the split bushing as you tighten the mounting bolts but I got it within a few thousandths of the old one


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## trlvn (Mar 21, 2020)

How do your new and old motors compare weight-wise?

Craig in Oakville


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## Chicken lights (Mar 21, 2020)

Gates has a laser pulley alignment tool that’s pretty handy


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## John Conroy (Mar 21, 2020)

The tag on the old one says 45kg or 99lbs. The new one says 96lbs. I lifted them both onto the bench yesterday and the new one feels heavier.


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## John Conroy (Mar 21, 2020)

Cool looking tool but for $1300 I can do it with a straight edge and ruler. LoL

https://www.royalsupply.com/store/pc/Gates-EZ-ALIGN-Laser-Tool-7420-1000-p16548.htm


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## Chicken lights (Mar 21, 2020)

John Conroy said:


> Cool looking tool but for $1300 I can do it with a straight edge and ruler. LoL
> 
> https://www.royalsupply.com/store/pc/Gates-EZ-ALIGN-Laser-Tool-7420-1000-p16548.htm


I didn’t look at the price, I just snagged a pic.
I want to say I payed $150 for mine?


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## John Conroy (Mar 21, 2020)

That sounds like a reasonable price and well worth it if you do a few jobs where alignment is a challenge.


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## David_R8 (Mar 21, 2020)

@John Conroy at the risk of distracting from this conversion, do you have a post on your mill conversion?


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## Dabbler (Mar 21, 2020)

Nice conversion post!  Very instructive!  I'm kinda lucky;  My mills are 3PH, and I share a VFD between them (and other machines) as they all have 2HP motors.... 

Did you buy a Teco 510 to control the motor?


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## PeterT (Mar 21, 2020)

JohnC, does the NEMA, IEC & other motor standards refer mainly to the frame/bolt pattern dimensions or also include motor shaft particulars like OD, extension length, key dimensions etc.? Was your sheave replacement necessitated by it being a better system or you just plain couldn't use the one from the old motor?

I'll be watching with interest, stay healthy!


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## John Conroy (Mar 21, 2020)

David_R8 said:


> @John Conroy at the risk of distracting from this conversion, do you have a post on your mill conversion?



I did it quite a few years ago and did post it but the pictures are all gone due to the Photobucket debacle. I do plan on updating it with new pics someday though


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## John Conroy (Mar 21, 2020)

Dabbler said:


> Nice conversion post!  Very instructive!  I'm kinda lucky;  My mills are 3PH, and I share a VFD between them (and other machines) as they all have 2HP motors....
> 
> Did you buy a Teco 510 to control the motor?



Thanks John, yep I bought the Teco L510. the exact model number is L510-203-H1-U which specifies it is for 240 Volt single stage input power and to power a 3HP three phase motor.


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## John Conroy (Mar 21, 2020)

PeterT said:


> JohnC, does the NEMA, IEC & other motor standards refer mainly to the frame/bolt pattern dimensions or also include motor shaft particulars like OD, extension length, key dimensions etc.? Was your sheave replacement necessitated by it being a better system or you just plain couldn't use the one from the old motor?
> 
> I'll be watching with interest, stay healthy!



The NEMA and IEC specs cover most dimensions including frame size, mounting bolt hole spacing and shaft diameter. You can find the specs here.

https://www.engineeringtoolbox.com/nema-electrical-motor-frame-dimensions-d_1504.html

https://www.baldor.com/~/media/files/brands/baldor-reliance/resources and support/backcover.ashx

I would have just bored the pulley ID from 28mm to 1-1/8" but I would need a lathe for that LoL. Seriously I would have needed to broach a keyway also so I just bought a new pulley.

I hope everyone stays healthy, this virus is serious. My son in laws Grandma died from it in Vancouver yesterday.


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## David_R8 (Mar 21, 2020)

Oh dear. I’m very sorry to hear that John. 


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## Tom O (Mar 21, 2020)

Sorry to hear that!


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## Dabbler (Mar 21, 2020)

My thoughts are with you and all your family.

I'm glad that everyone is taking this seriously.  The roads and offices are empty, nearly.


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## JohnnyTK (Mar 21, 2020)

Sorry to hear that John!


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## John Conroy (Mar 21, 2020)

Thanks guys, I'll pass along your condolances to my daughter Erin and her husband Cam.


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## John Conroy (Mar 21, 2020)

Well it seems like I accomplished very little today. I think the most stressful step is done, pulling out all the original wiring. For that I had to move the machine away from the wall so I got a chance to use the skates I built months ago. They worked well, I used some plastic bondo spreaders for wedges to keep it from rolling too far as my floor is quite sloped.














Power comes into the  machine at the junction block on the left, then to the red switch on the right, then to the controls. I intend to have power from the switch feed the VFD and the original switches for forward/reverse, jog, chuck and door safety switches. This will eliminate all the original contactors and controls.


More to come tomorrow.


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## John Conroy (Mar 22, 2020)

Today I messed around bench testing the VFD operation. With the motor and vfd on the bench I temporarily wired the single phase 240 to the vfd and connected the 3 phase motor output leads to the motor using some of the scrap wiring I removed from the lathe yesterday. The 5Kohm potentiometer I ordered from Amazon arrived this morning so I also wired it as well as the forward and reverse switches and the jog button and configured the vfd to accept those remote inputs. The Teco L510 vfd comes with a 152 page manual which is very good ( light years better than the Huanyang vfd manual) but it takes alot of reading to figure out which setting parameters to use.I think I've got the hang of it now and I have most of the basic settings the way I want them. I have used 3 of the 5 available switch inputs for forard, reverse and jog. Tomorrow I will use the last 2 for the safety switches. The chuck guard, emergency stop and gear cover door switches will be connected to the same input and will trigger a stop with dynamic braking(stop the chuck in 3 seconds from 1800 rpm). The last input will be for the brake pedal switch which will trigger a coast down stop, you can't use mechanical and dynamic braking at the same time. I shot a short video of running it through it's paces just before quitting for the day. The motor is so smooth and quiet I didn't think it was going 1800 rpm that it's rated for so I wrapped black duct tape around the pulley and used a piece of foil to trigger my photo tach. You can see in the video that it is right on the money for speed.


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## David_R8 (Mar 22, 2020)

Wow John, that's impressive. Eerily smooth and quiet.


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## PeterT (Mar 22, 2020)

John, re the dynamic braking, is the 3 secs stop from 1800 rpm kind of a safe stock mode power absorption thing? In other words, if you were only doing 900 rpm could the stop time be reduced to 1.5 secs etc. or does it not work that way? When do those big surge/brake resistors (or whatever they are called) come into play like when you see guys threading to a shoulder & it looks almost instant?

Anyways, looking good!


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## Dabbler (Mar 22, 2020)

Your motor doesn't whine like mine on the same VFD...  Hmmm  Perhaps I need a rethink...


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## John Conroy (Mar 22, 2020)

Peter, you can set the dynamic braking to what ever amount of time you want. The settings are proportional as you thought. If you set it for 3 seconds at 60hz it will stop in 1.5 seconds at 30hz or .75 seconds at 15hz. If you stop,it too fast the counter emf generated by the motor can cause more cuŕent flow back into the vfd than it can handle and cause an over current error so you have to try different settings to see what will work for your machine. The mass of the chuck and parts held in it have a huge effect. Some vfd's have provisions to connect an external braking resistor to help shed the current but these small Teco ones have an internal braking resistor only. You have to read the manual closely to find that only the 460 volt models allow and external one. The same goes for accelleration times. Heavy chucks and fast accelleration can cause over current errors. If you watch Clough42's series of videos he demonstrates those error situations.

John, there is a way to fix the whistle noise. There are 2 parameter settings to change but my notes are out in the shop so I will post them tomorrow. They are covered in Clough42's video series also. I noted them while watching because my Hyanyang does it too and I'm hoping it has the same settings.

If you turn the volume up in the video you can hear a little of the chirpy noise during dynamic braking. You can see at the end it was at 60hz forward and I switched to reverse while it was still at full speed. It stopped and accellerated to 60hz in reverse in 6 seconds. Something you could never do with a single phase motor.


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## Dabbler (Mar 23, 2020)

Very nice programming!  runs very smoothly!


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## John Conroy (Mar 23, 2020)

The 3 setting parameters Clough42 adjusted to reduce the whistle/chirp noise and improve motor smoothness are:

Parameter 00-00 "Control Method" should be set to 1 for "SLV Mode" (sensorless vector)

Paramter 11-01 "Carrier Frequency" is set at 5Khz from the factory, if you set it to the maximum 16Khz to noise will be nearly out of the human hearing range so you will barely hear it.

Parameter 11-02 "Carrier Mode Selection" should be set to 0 for 3 phase PWM. For some reason the factory default setting is 1 for 2 phase PWM

In the video I have already set the Carrier Frequency to 16Khz and changed the Control Method to SLV but forgot about Carrier Mode Selection. I will change that this morning and see if it gets rid of the slight roughness in the middle frequency range.

Teco-Westinghouse sells the same motor as mine in a 3600 rpm version (PDH3400 is 1800 rpm qnd PDH3200 is 3600 rpm) and my motor data sheet says the motor can run up to 120HZ so theoretically I could increase the maximum run frequency but for now I'm going to leave it at 60HZ max to prevent damage to the lathe gearbox. The lathe has 8 speeds from the factory and the 2 highest are 1200 and 1800 rpm, a huge gap. Now with the gear box set in the 1800 rpm position I will be able to get 900 rpm at 30HZ, 1200 rpm at 45HZ or basically any rpm between 1 and 1800 I want. I can hardly wait to try it out. 

Today I am going to work on the VFD enclosure and maybe get some of the final wiring installed.


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## kevin.decelles (Mar 23, 2020)

I’ve adjusted the carrier frequency on a huangyang to eliminate a whistle on a 7.5 hp motor as well. 


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## Tom O (Mar 23, 2020)

I have a 30 Kv phase perfect for my 3 phase needs and am looking for a 3 phase circuit box so I can wire in some more outlets, does anyone know where I might get a cheap breaker box?


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## Dabbler (Mar 23, 2020)

@John Conroy - that's it!  I didn't change from 2 phase PWM to 3 Phase PWM...  that would account for the whine!  I haven't noticed too much loss of torque, but I'm sure it is less also!  thanks for the help!


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## Tom Kitta (Mar 23, 2020)

3ph breakers are not cheap at all - I would look into auction houses. You have essentially 3 breakers for each connection 1 per phase. Plus its seen as commercial stuff so expensive.


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## John Conroy (Mar 24, 2020)

I was thinking I would be able to keep the wiring dead simple like my mill VFD but the further I go with this project the more complex it becomes. I spent the whole day removing the 5 original contactors and the 240-120-24 volt transformer and it's fuses, then re configuring the wiring to include only the main contactor, the transformer and the fuses for the 120 and 24 volt busses. I ran all the wiring for the inputs needed to include all the safety features that came with the lathe. That will include and emergency stop switch, a chuck guard switch, a gear cover door switch and a brake pedal switch. All these switches were configured as normally closed. I reconfigured  all except the chuck guard to be normally open as it is easier to set up the vfd for them that way. I will post pictures of all that tomorrow.
I also got the new motor installed and the belt tension adjusted. I turned the wire box on the motor 90 degrees so the wires protrude toward the front of the motor instead of straight down. I ran into a small problem along the way, the motor wire box sticks out further than the old motor and will require some modification to be made to the rear motor cover. Just a little sheet metal work and I also going to add a cooling fan to the motor compartment. When the motor is operating at reduced frequency it may need some help moving air as it will be turning slower.


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## PeterT (Mar 24, 2020)

Step by step, coming along!

- does the new motor have the classic grill on the cover end with its own fan inside? Which way does air blow normally?

- I thought I read somewhere that the jog switch itself is special on a regular 2-phase motor, but there was more to the circuit than the equivalent of a short duration switch so somehow be easier on the motor. But now I've had start capacitor issues cross my radar I can't even visualize how jog is working in conjunction with those given the short duration. More known unknowns LOL. Anyways, how does jog factor into a VFD driven motor?


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## John Conroy (Mar 24, 2020)

The new motor has the fan in the same place but the shroud is about 15 lbs of cast iron. Air is drawn in from the rear and forced out over the cooling fins. The jog function on my single phase motor was basically the same as forward speed for as,long as you hold the button. With a vfd you can set if up however you want, the default is forward at 25HZ with 2 second accelleration time.I am going to leave it like that for now. I have my mill set up to jog in forward or reverse at 15HZ.


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## PeterT (Mar 24, 2020)

Ah. So you mean the same jog switch on the machine is rewired to one of those VFD ports & programmed to function a certain way when 'on'?


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## John Conroy (Mar 25, 2020)

That's right, there are 5 switch input terminals on this VFD and you can select a function for each of them.






In my case I have set parameter 03-00 to 0 and 03-01 is set to 1, those are the factory forward/reverse switches that are operated by the giant lever on the apron.

Parameter 03-02 is set to 6 and in the chart you can see thhat I can then go and set parameter 00-18 to 00-20 to define the conditions for "jog forward" which is switch S3 the factory jog button momentary switch.

I have the E-stop switch hard wired to turn off the main contactor which will remove power to the VFD. 

Which means I still have parameters S4 and S5 avaiable and I plan to connect the chuck guard switch and gear cover door switch to S4 and set the paramater to 14 for rapid stop so if either switch changes states the motor will stop with dynamic braking.

 Last I will connect the foot brake switch to S5 and set the parameter to 15 for a coast to stop (no dynamic braking) so the mechanical brake is not fighting with the electronic braking.

I hope that all makes sense, I have been reading the manual so much that my brain has gone fuzzy.


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## YYCHM (Mar 25, 2020)

Posted at 4:38 AM????

This is really interesting stuff BTB.  Thanks for sharing.

Craig


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## John Conroy (Mar 26, 2020)

Good eye Craig, I have  developed weird sleep habits since I retired! My wife was beginning to wonder if the lathe would ever work again and I underestimated how long it would take me to get this done. Since I started last Friday, I have probably spent 50 hours in the shop working on this and another 8 hours reading the VFD manual and making notes. I have to say It is hard to believe you can buy a piece of equipment as sohisticated as this VFD for $350. But as of 8pm  Wednesday, it lives! I will post a link to a video I shot after working 10 hours on it yesterday and seeing it run for the first time, I was a little spaced out. I wound up with a more complicated wiring configuration than I thought with 3 control input cables running from the front switch panel directly to the VFD and another 4 from the factory junction box on the back of the machine to the VFD for a total of 7 cables running to and from the VFD enclosure. From the original elecrical content I re-used the main contactor, the transformer that steps down the 240 to 120 volts ac  and 24 volts dc, 2 DIN rail mounted fuse holder, the main bus bar and some cable. I could have managed with fewer cables, I used 24 guage cat 5 with 4 twisted pairs in each cable for the controls but the motor and VFD are a very electrically noisy environment and I wanted to seperate most of the inputs to reduce the chance that EMI would create control problems. Power to the VFD and the motor is through 12/3 cable. I bought the VFD enclosure, the fan and it's power supply, the cable glands the potentiometer and all the terminal ends on Amazon so I could avoid exposure to other people. Of course I wound up with more of some of that stuff than I really wanted, 20 Potentiometers and 50 cable glands but such is the nature of online shopping. I am impressed with how fast Amazon can deliver, I orderd the enclosure at 8pm on Sunday and it arrived at 3 pm Monday.
I mounted the enclosure so that the digital display on the VFD is visible through a 3 inch window I cut in the front and I also cut two 4 inch holes in the sides for the fan and outlet air grills. Only 2 of the cable knockouts were the right size for the cable glands I bought so I had to drill some extra holes in the bottom of the box and weld 3 washers on to size the knockout holes that were too large. The box it 10 X 10 X 6 inches.
Here are a few pics, I will post a link to the vid after I upload it to YouTube.


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## John Conroy (Mar 26, 2020)




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## Johnwa (Mar 26, 2020)

John
I need a schematic!  I have way less wires but I know I left a few things out.  Ex.  No remote speed knob and no brake. Probably some other things too.
cheers
John


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## Dabbler (Mar 26, 2020)

very professional job!  My VFD for the mill looks cobbled together!


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## PeterT (Mar 26, 2020)

That looks awesome John. Good job! 
I'm pretty sure you could write a #1 bestseller How-to manual & re-coup your VFD expense. But you probably are itching to get back to work!
Hope you kept lots of pics & notes, suspect others will follow now that you've blazed the trail.

Just to clarify, did you do the motor/vfd package scoping out on the main (USA) link you provided & they shipped to Edmonton, or Edmonton just happened to have what you were after?
_I purchased a Teco-Westinghouse motor and compatable VFD online and picked up at the *Edmonton Teco-Westinghouse warehouse* the same day._


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## Tom O (Mar 26, 2020)

That’s one heck of a nice job!


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## John Conroy (Mar 26, 2020)

Thanks guys.
Johnwa, for now the schematic only exists in my head but I plan to make one and note all the programming details.

Dabbler, my mill VFD wiring is pretty cobbled together also. I decided to do this one better because I have lots of time and this lathe is a new machine.

Peter, I dealt with EMotorsDirect.ca, the Canadian version. I think they drop ship direct from the vendors who have warehouses all over the country. They offer free pickup if they have a warhouse in your area. This is the motor I bought, it shows stock in Calgary so they must warehouse there too.

https://www.emotorsdirect.ca/item/teco-pdh0034

This is the VFD I bought, it is the most simple one they sell and only available for motors up to 3HP. Corey, the sales guy I dealt with  recommended it because it's the easiest to set up and program. The programming is very similar to the Huanyang on my mill. I think the Huanyang is a clone of the Teco.

https://www.emotorsdirect.ca/item/teco-l510-203-h1-u


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## John Conroy (Mar 26, 2020)

Today I got the lathe put back in place and levelled again. I left it about 6 inches further from the wall than before so I can get the rear electrical door open if needed. Then I cleaned up the whole garage/shop as it had become quite a mess in the last week. I played around with accelleration and decelleration times. Since this model VFD can't be fitted with an external braking resistor you have to program to the limitations of the vfd. With my heaviest chuck installed I tried setting decel to 3 seconds from the factory default of 10 seconds but from 1800 rpm the vfd would display an over current trouble message. I settled on 5 seconds as it reliably stops with no faults from that speed with no fault message. I also played with the wide range of speeds available now. I will be changing gear ratios alot less now. Most of the time I'm working between 200 and 1200 rpm. If I leave it the 1200 rpm gear, at 10HZ it turns 192 rpm so just that one gear will do for most of my work.
I shot a couple of quick vids. In the first one the machine sounds really loud but it's because the camera is sitting on top of the gear box. Doing math in my head didn't work out too well either, 15HZ is about 300 rpm not 500.


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## John Conroy (Mar 26, 2020)

Here's a quickly drawn schematic. I will detail programming tomorrow.


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## John Conroy (Mar 26, 2020)

I found that the 2 page quick start guide does an excellent job showing you how to use the keypad and display to program the drive and gives examples of the most commonly used parameters so you can easily be up and running in just a few minutes after the wiring is done. There were just a few more advanced settings based on info I got from the Clough42 videos and dealing with the normally closed switch on the chuck guard. Here is the quick start guide and my set up.


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## PeterT (Mar 26, 2020)

Bravo. The VFD certainly gives a wide speed range. That slow tickover is insane. What are your thoughts on "one gear complacency syndrome" LOL. Maybe install an rpm display so you basically ignore the frequency, turn the number to whatever rpm makes sense but allows you spread the gear selection around a bit?


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## John Conroy (Mar 28, 2020)

My temporary solution to the motor extra width was to cut a hole in the cover. I have ordered a fan and enclosure from Amazon. My plan is to mount the fan over that hole to blow air over the motor. This will aid cooling and make the motor compartm


ent air pressure higher than atmosphere and help keep dust out. Not sure it really needs a fan but better safe than sorry


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## PeterT (Mar 28, 2020)

Maybe cheesy idea but could you source an appropriate sized electrical mini panel housing box (or whatever they are called), trim it to desired stick-out width... similar to what you did on the VFD box? Might not be worth the cost/effort but from what I've see of home made boxes, its either sheet stock TIG'd together or homebrew vise bending brake... unless one has access to the typical equipment.


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## Johnwa (Mar 28, 2020)

John
Thanks for the schematic.   I should draw up mine. Effectively I have the top three lines of your drawing, Common, Reverse, and Forward.  I do have a start and stop switch wired in but I’m going to have to trace it out as I can’t remember exactly how I did it.  I made use of the original Start, Stop, and the F/R drum switch.
After yesterday I think a chuck cover and switch is a good idea!  My Chinese VFD does have braking resistor connection which I will have to figure out.  In the meantime I will duplicate your process for setting deceleration.

John


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## John Conroy (Mar 28, 2020)

Peter, that is exactly what I have planned. Too much work to make a box when you can buy one for $15.

John, one more parameter I ran today seemed to smooth the motor performance is called auto tune.


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## John Conroy (Mar 29, 2020)

I just updated the schematic in post #50 to include the front panel mounted E-stop switch. When pushed it interupts the 24 volt control circuit to the main contactor. The contactor opens and removes 240 volt power from the VFD. That is the way I configured the wiring from the start, I just forgot to include it on the drawing.


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## John Conroy (Mar 29, 2020)

Link to the Teco manual.

https://drive.google.com/file/d/1ljcx4BY24sPlFsrKKeJGsoO0Y4cBcNYX/view?usp=drivesdk


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## John Conroy (Mar 29, 2020)

I've been reading  information from Teco and Huanyang that says that high carrier frequency is hard on the IGBT's (large power transistors) in the VFD. Both companies warn that setting the frequncy to high will shorten the life of the IGBT's. With that in mind I decided try lowering the frequency setting I made ,16K HZ which is the maximum Teco allows. The reason to have it high is to eliminate the noise made by the transisitors. I lowered ot to 10K HZ and the sound is still almost inaudible so I'm going to leave it there. It is set with parameter 11-01


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## JohnW (Mar 29, 2020)

Switching circuits are usually more efficient at lower frequencies. The goal is usually to try to get above 20KHz since most noise generated by that is inaudible to humans. For old people the limit is close to 12KHz. A young'in may complain about the high-pitched squeal from the VFD / wiring / motor coils when you don't hear it.The noise comes from the rapidly changing magnetic fields causing metal around them to vibrate.

Why? Because the IGBT's in the VFD (just like the FET's in most switching supplies) are run either fully on or fully off for minimum heat / maximum efficiency. When off there is no current flowing, so there is no heat. When fully on the devices will make very little heat. In the case of a MOSFET, the on resistance can be in the 0.01 to 0.001 ohm range. Using P=I^2R, the power dissipated is low, even if a few amps are flowing through it. With IGBT's the semiconductor junction will have a semi-fixed voltage drop somewhere in the 1-3V range. So with 10 amps flowing, it will dissipate 10-30 watts while turned on.

The current to the motor is varied by changing the ratio of on to off, not actually changing the voltage. The output frequency (5-100Hz for instance ) is generated by varying the motor current in a sine wave at 5-100Hz, by changing the on-off ratio at 20KHz.

The real problem is what happens as the switching devices (FET or IGBT) change from on to off.  During that time period it is partially conducting, and just like a resistor it will dissipate lots of heat during the transition. Fortunately, the switching time is very short (IGBT's at well under a millionth of a second, FETs are somewhat faster). Why not use FET's since they seem to be better - it is because they are hard to make operate at 400+ volts, while IGBT's are easier to make for higher voltages.

The devices switch quickly, but if you are running the VFD at 20KHz, you are transitioning from on to off or off to on 40,000 times per second. 40,000 transitions at 0.5us per transition means the device is partially conducting (called linear mode) for 2 percent of the time. (20,000/1,000,000 = 0.02 = 2%). That means it is generating significant heat for 2% of the time. Reducing the switching frequency to 10KHz means it is only producing significant heat for 1% of the time, which is much easier on the device.


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## John Conroy (Mar 29, 2020)

I agree John. Teco has  built in overheat protection measured at the IGBT heat sink. If the temp gets too high the programed response is to lower the carrier frequency to 4 K HZ.


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## John Conroy (Mar 29, 2020)

It looks like Huanyang allows carrier frequency as high as 20K HZ on some models but the factory default must be quite low because mine sure makes alot of noise. I'm going to check what it is and raise it to 10.


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## John Conroy (Mar 29, 2020)

Ok I just went out to the mill with the Huanyang VFD and checked parameter pd041 which is the carrier frequency. It was set at 3 which as you can see in manual page above = 2K HZ. I increased it to 10 which = 10K HZ. What a difference! The noise is gone. Wish I'd know about this years ago. Tomorrow I will make a before and after video and see if the noise difference can be heard on the vid.


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## JohnW (Mar 31, 2020)

That is a cool feature that automatically lowers the PWM frequency as the heat goes up.

It is unlikely that most hobby lathes would have overheating problems anyway, even at high frequencies. The current through the IGBT's (proportional to the heat) is also proportional to the amount of load you have on the motor. It might be a 3HP motor that will draw maybe 10-15 amps through 3 phases at 220V. It would only draw that much power if you were doing extremely heavy cuts. Most times you would be loading it down much less than that and using less than 1 HP with less than a third of the current and a third of the heat build up in the VFD..

I actually run a 5HP 3-phase motor motor on a 5HP rated VFD, except I'm only feeding the 3-phase rated VFD with single phase (220V split phase actually), so it needs to be de-rated to about 3HP. I've never had a problem. I've probably almost never used more than 2HP.

The VFD's are pretty durable with over current, over voltage and over temperature safety sensors. It will almost certainly shut itself down before it is damaged from too high a load. You can usually set some of the safety parameters to lower values for some extra protection.


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## John Conroy (Apr 1, 2020)

I received the fan and enclosure from Amazon so I moved the lathe away from the wall again. The difference this time was I used my new toe jack to lift the machine high enough to get the skates under it. Instead of an hour it took 5 minutes to get it moved away from the wall. The box is 6 X 9 inches and 3 inches deep and the fan is 120mm by 30mm and powered by 120 volts, this thing moves alot of air. I mounted the box to the rear motor cover and mounted the fan to the lid. I ran 120 volt power from the transformer and mounted a switch in the box with the vfd. The fan grill has not arrived yet but will be easy to install when it does. I plan to use the fan in hot weather or when working the lathe hard.
























After using the lathe far a week since the conversion I am extremely happy with it. As Sherman T. Potter would say, there are not enough O's on smooth to describe it.


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## JohnW (Apr 1, 2020)

I did almost exactly the same thing for my VFD'd motor. Great minds obviously think alike!




My fan is a very powerful 24V unit (from an old IBM mainframe) powered by an old 20V laptop supply. It is powered by a small relay that is connected to one of the VFD outputs. I programmed the VFD to turn the fan on whenever there is power to the motor. the fan blows on to the side of the motor.


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## PeterT (Apr 1, 2020)

Very professional.


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## John Conroy (Apr 2, 2020)

John, I probably should have  used the RA and RB terminals of the VFD and programed it like that but after hearing the fan I decided to make it manually controlled. 

Thanks Peter. I'm really liking the variable speed function, I was getting some chatter while parting off a piece of stainless and was able to just dial down the speed a bit to correct it without stopping the cut. Very cool!

This social distancing is starting to wear on me. I went down to KMS to buy a 4 1/4" hole saw to cut the hole for the fan and I was the only person on the store except 2 staff, both behind plexiglass shields. Strange times!


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## shooter910 (Apr 2, 2020)

Thanks for sharing your adventure with this project it has helped me more than you will know!!
I had the exact problem with my start capacitor on the exact same weekend as you and have been doing the same 3 phase conversion (with help from our local motor repair shop) and have been using it for a few days now and last night i was parting off just as you said in you previous post and the variable speed is awesome!!!  I will never have a lathe without it again!!

I was keeping an eye on this thread and thinking how similar your situation is to mine and kind of chuckling to myself but when you posted about the parting off....chills went up my spine!!

I have even made a similar quick change tool holder rack to yours...

thanks for letting us in your shop!!


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## kevin.decelles (Apr 2, 2020)

Hi John , this is pushing me to a project! Great work!

Quick question, how much of the stock relays/fuses/non-wire electrical parts did you reuse from the stock machine? Im pretty comfortable with the vid programming, but was wondering if you had to reuse any of the stock bits 


Sent from my iPad using Tapatalk


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## John Conroy (Apr 2, 2020)

shooter910 said:


> Thanks for sharing your adventure with this project it has helped me more than you will know!!
> I had the exact problem with my start capacitor on the exact same weekend as you and have been doing the same 3 phase conversion (with help from our local motor repair shop) and have been using it for a few days now and last night i was parting off just as you said in you previous post and the variable speed is awesome!!!  I will never have a lathe without it again!!
> 
> I was keeping an eye on this thread and thinking how similar your situation is to mine and kind of chuckling to myself but when you posted about the parting off....chills went up my spine!!
> ...




Wow, weird coincidences! Are you going to post about your upgrade?


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## John Conroy (Apr 2, 2020)

Kevin, in the picture of the original electrical panel the parts I salvaged from it are, the main contactor in the upper left, the 2 fuse holders in the upper right, the transformer in the lower right, the mounting plate with 1 strip of DIN rail, and the bus bar on the bottom. 1 fuse is for the 24 volt control circuit and the other for the 120 volt circuit for the DRO and the new fan. The second pic shows everything except the fuses.









My wiring is not quite as neat and organised as the original. LoL I should have set up the entire panel on the bench instead of one piece at a time while it was mounted on the lathe. I didn't sit down and draw the schematic until it was finished. I didn't think it would look quite so chaotic when I was finished.




The little orange gizmo on the laying on the bottom is the 120 to 12 volt power supply for the fan in the VFD enclosure.


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## shooter910 (Apr 2, 2020)

John Conroy said:


> Wow, weird coincidences! Are you going to post about your upgrade?



I had not really thought about that, to be honest I never took may pics mostly just wiring stuff as a way to remember where thing were.  but i do have a couple of it together...












the vfd mount was recommended by my motor repair guy he said in a home shop it will handle any dirt i will be making and the aluminum will help heat dissipation 
That motor was fun to get in there!!  you can see the tool holder rack in the last one
i mostly took these pictures to show what my lathe looks like clean, unfortunately i am not the guy that keeps it spotless


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## John Conroy (Apr 2, 2020)

Nice install. My vfd has an open chassis so it has to go in an enclosure.


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