Chapter 2: Frequency Inverter

[Bill Boehme]

Wish I could use your Motor! I was told my VFD could run a 3HP motor, but not to its full potential, is that right?

Oh, so it sounds like what you have is really a 2 HP inverter. It can be used in constant torque mode with a 2 HP motor and in "variable torque" mode with a 3 HP motor. What this means in simple terms is that you can operate the 3 HP motor as if it were a 2 HP motor. I can do the same thing with my 2 HP Baldor inverters. They can be used to the full capability (constant torque mode) of a 2 HP motor. I can use them with my 3 HP motor, but limited to a 2 HP maximum performance. Depending on the application variable torque might be fine, but I think that you are wanting low speed torque for roughing.

Don't you have several other lathes that you can use? Maybe it's time for a Robust lathe.

 

[olaf Vogel]

I wish you or @Bill Boehme Boehme would come to Maui, I have a room for you guys.

Hey Emiliano, I'd happy to come to Maui - if you have space on your couch!
I spent a month in Kauai a few years ago and fell in love. No heating, no A/C just perfect weather 300 days a year. And great wood to turn....ah...paradise.

You have ordered the parts, so are locked into that course of action, but, in the meantime, maybe as Bill suggest, check all the mechanical stuff (if you have not done so already)

- belts slipping
- spindle slipping

Have a friend watch the two shafts, as you stall the wood blank. See if either show slippage. If not, all the issues should be at the motor.

Check for excessive resistance / friction:
- spin the spindle by hand checking for friction.

If there is a lot, then drill down. It could be the lathe, spindle or motor bearings or the belt rubbing (not likely)

I can't think of any other mechanical problems.

So it might be the motor's insulation has gone bad, as Bill suggests. I've never had it happen, but I defer to his greater experience on this. My own reading of the Baldor documents, confirms his statements.

You also mention that your VFD might rated for 2 hp, while the motor is 3 hp.
I.e. the VFD would not supply enough AMPs for full power. Thats VERY possible. On my VFD's (Delta) brand, that usually triggers an error for overload. You'll have to check your own brand.

Lastly, is this a "converting VFD"? I.e
1 - is it plugged into a 220v single phase circuit? Or
2 - do you have a Phase Converter upstream that creates a 3 phase solution for your shop
This is critical. Because if #1, then your VFD will almost guaranteed not be able to supply enough AMPs to the motor. and that my be your issue.

The optimal setup is a Rotary Phase Converter (RPC), for all your machines, so they have lots of clean 3 PH power.
Then use VFD's to control the speed. RPC's are cheap and easy to build, especially if you have a big ol' 3 PH motor spare.

Additionally, there's a great bunch of people at OWWM. They specialize in restoring old machines - which means tackling a ton of tricky issues. OK -your Stubby is not old, but they will try to help and have tones of experience with VFDs / motors, 3 PH, RPC. http://www.owwm.org/viewforum.php?f=82&sid=0d775e02fe3d80ed5e07c1dc1cc216b4

They will run you through a similar checklist, as above.

Lastly, while you are waiting, possibly consider a different turning tool. I often use an Oland tool

View: https://www.youtube.com/watch?v=gbNst5EvsG4
for removing large amounts

Its a smaller cutting tip, so requires less HP, and still removes a lot, very fast.
But leaves a poor surface, so you need to follow up with a nice finishing cut.

Let us know how you are setup and maybe I can help further in trouble shooting.

 

[Emiliano Achaval]

Hey Emiliano, I'd happy to come to Maui - if you have space on your couch!
I spent a month in Kauai a few years ago and fell in love. No heating, no A/C just perfect weather 300 days a year. And great wood to turn....ah...paradise.

You have ordered the parts, so are locked into that course of action, but, in the meantime, maybe as Bill suggest, check all the mechanical stuff (if you have not done so already)

- belts slipping
- spindle slipping

Have a friend watch the two shafts, as you stall the wood blank. See if either show slippage. If not, all the issues should be at the motor.

Check for excessive resistance / friction:
- spin the spindle by hand checking for friction.

If there is a lot, then drill down. It could be the lathe, spindle or motor bearings or the belt rubbing (not likely)

I can't think of any other mechanical problems.

So it might be the motor's insulation has gone bad, as Bill suggests. I've never had it happen, but I defer to his greater experience on this. My own reading of the Baldor documents, confirms his statements.

You also mention that your VFD might rated for 2 hp, while the motor is 3 hp.
I.e. the VFD would not supply enough AMPs for full power. Thats VERY possible. On my VFD's (Delta) brand, that usually triggers an error for overload. You'll have to check your own brand.

Lastly, is this a "converting VFD"? I.e
1 - is it plugged into a 220v single phase circuit? Or
2 - do you have a Phase Converter upstream that creates a 3 phase solution for your shop
This is critical. Because if #1, then your VFD will almost guaranteed not be able to supply enough AMPs to the motor. and that my be your issue.

The optimal setup is a Rotary Phase Converter (RPC), for all your machines, so they have lots of clean 3 PH power.
Then use VFD's to control the speed. RPC's are cheap and easy to build, especially if you have a big ol' 3 PH motor spare.

Additionally, there's a great bunch of people at OWWM. They specialize in restoring old machines - which means tackling a ton of tricky issues. OK -your Stubby is not old, but they will try to help and have tones of experience with VFDs / motors, 3 PH, RPC. http://www.owwm.org/viewforum.php?f=82&sid=0d775e02fe3d80ed5e07c1dc1cc216b4

They will run you through a similar checklist, as above.

Lastly, while you are waiting, possibly consider a different turning tool. I often use an Oland tool

View: https://www.youtube.com/watch?v=gbNst5EvsG4
for removing large amounts

Its a smaller cutting tip, so requires less HP, and still removes a lot, very fast.
But leaves a poor surface, so you need to follow up with a nice finishing cut.

Let us know how you are setup and maybe I can help further in trouble shooting.

Lots of great info here! Thank you for your help. I will show this to my engineer friend, it's above my pay grade. He should know the answers about the vfd. We did check the power supply.

 

[Richard Coers]

I asked my go to motor and VFD guy. He said it sounds like you programmed the torque boost on the VFD, but then you didn't turn it on in the programming. His words, not mine. I thought maybe it might help you.

 

[Bill Boehme]

Lastly, is this a "converting VFD"? I.e
1 - is it plugged into a 220v single phase circuit? Or
2 - do you have a Phase Converter upstream that creates a 3 phase solution for your shop
This is critical. Because if #1, then your VFD will almost guaranteed not be able to supply enough AMPs to the motor. and that my be your issue.

The optimal setup is a Rotary Phase Converter (RPC), for all your machines, so they have lots of clean 3 PH power.
Then use VFD's to control the speed. RPC's are cheap and easy to build, especially if you have a big ol' 3 PH motor spare.

I agree with most of what you said, but it's not quite that straightforward. There are inverters designed for only three phase input, others designed for only single phase input with no provision for three phase, and others designed for three phase input that can also be used on single phase that may or may not need to be derated for single phase operation. For example I have a couple Baldor series 18H two horsepower 230 volt inverters that are designed for three phase operation, but they can be used on single phase power without derating. But, series 18H inverters rated from 3 HP, but less than 15 HP need to be derated 40%. For 15 HP and above the inverters need to be derated 50%. What this means if I had a 3 HP motor and wanted to use single phase power to an 18H inverter is that I would need to get an 18H inverter rated for 5 HP.

The need for derating is mainly because of the maximum current rating of some of the internal components in the inverter and not directly related to single versus three phase. There are other 3 horsepower inverters that are for single phase only operation and probably some that can be used with either single or three phase power that don't need to be derated when used on single phase power.

No matter which type you have, they all have one thing in common ... the AC input is rectified and filtered to produce a DC power supply that is used to drive the PWM output stage to the motor. The maximum output current to the motor is primarily due to the maximum current rating of the output switching transistors. However, maximum input current can sometimes be a preemptive limiting factor for single phase operation.

Your solution of using a RPC would be ideal if your inverter needs to be derated for single phase operation.

 

[Bill Boehme]

I decided to take a look at the motor on the WEG site. For some reason I had assumed that it was a 3 HP motor, but it turned out to be 2 HP. I should have known since it is the Stubby S750. Here is the link.

 

[Bill Boehme]

I'm not happy with it. I had a club member engineer over, he tweaked it but still not working right. I do not have torque. What looks like the main torque parameter P0009 suppose to be adjustable to 1000%, but you can't adjust it. It's at ZERO.

I looked at the WEG programming manual and it appears that a password has been set so that some parameters can't be changed. But, there is a flag that can be set to 1 to allow changes to be made. I forgot to see which page in the manual I saw this. There is only about a hundred pages so it shouldn't take but a week or two to find it.

 

[Emiliano Achaval]

I looked at the WEG programming manual and it appears that a password has been set so that some parameters can't be changed. But, there is a flag that can be set to 1 to allow changes to be made. I forgot to see which page in the manual I saw this. There is only about a hundred pages so it shouldn't take but a week or two to find it.

Wait a minute!! Are you telling me I can change P0009? Bill, I will send you a flat rate box with some Koa if you tell me how to unlock P0009 and change the torque setting!!!!! Start reading! LOL

 

[Emiliano Achaval]

I asked my go to motor and VFD guy. He said it sounds like you programmed the torque boost on the VFD, but then you didn't turn it on in the programming. His words, not mine. I thought maybe it might help you.

Everything helps! Looks @Bill Boehme might be onto something!

 

[Emiliano Achaval]

I decided to take a look at the motor on the WEG site. For some reason I had assumed that it was a 3 HP motor, but it turned out to be 2 HP. I should have known since it is the Stubby S750. Here is the link.

Correct, I have a 2hp motor. I really appreciate you looking into this Bill. If you can unlock P0009 and tell me how to do it, we will surprise quite a few people!

 

[Doug Rasmussen]

This thread is getting confusing to me.

Back in October 2018 a thread mentioned a new VFD for a Stubby 750 lathe to cure a (unexplained) problem. That VFD was "perfect", presumably meaning it solved whatever the lathe's problem was. Was that the $1800 VFD?

Now the same (?) Stubby 750 lathe is having issues diagnosed as a bad motor so a new $500 WEG motor was ordered (which can't be returned). And yet still another new motor and VFD are soon to arrive along with a new Stubby 1000 lathe.

What is this about unlocking P0009? If a parameter is locked on a manufacturer supplied VFD it may be locked for a reason, most likely safety. In my experience locked parameters usually are password protected and without the password you may be out of luck (Grizzly does that with their lathe VFD's, even their tech support can't unlock their VFD's).

Emiliano, I fully understand your isolation on Maui with few options to help diagnose electrical issues. I find it surprising the lathe maker has not been more involved in helping you, this process of replacing components until you find the real issue can get expensive. IMO, it doesn't speak well for the manufacturer.

 

[Bill Boehme]

What is this about unlocking P0009? If a parameter is locked on a manufacturer supplied VFD it may be locked for a reason, most likely safety. In my experience locked parameters usually are password protected and without the password you may be out of luck (Grizzly does that with their lathe VFD's, even their tech support can't unlock their VFD's).

It's a new VFD that hasn't been programmed with anything yet, but possibly the parameter that sets a password was changed (not certain about that but it might be the reason for not being able to change some parameters). I haven't dug into it yet, but based on Emiliano's earlier comments P0009 might be one of the PID parameters (the proportional gain is my guess). The programming manual tells how to override a locked parameter without needing to know the password.

 

[Doug Rasmussen]

It's a new VFD that hasn't been programmed with anything yet, but possibly the parameter that sets a password was changed (not certain about that but it might be the reason for not being able to change some parameters). I haven't dug into it yet, but based on Emiliano's earlier comments P0009 might be one of the PID parameters (the proportional gain is my guess). The programming manual tells how to override a locked parameter without needing to know the password.

More confusion.......

What new VFD? Where did this one come from?

 

[Karl Loeblein]

Emiliano, I'm thinking P0009 parameter is 'read only' which explains why it can't be set. The manual says this parameter indicates the torque developed by the motor in relation to the rated torque.

I'm curious to follow along just in case my VFD or Motor ever needs replacing. I'm a little confused like Doug. What is the specific WEG CFW500 VFD model and motor specs that you're trying to use on the Stubby 750? Are you still trying to get to old motor working that maybe broken, or are you working with a newer motor now?

Please keep us posted with the final solution, and post some pics of the $1,400 KOA bowl when your finished with it.

​

 

[Karl Loeblein]

… No matter which type you have, they all have one thing in common ... the AC input is rectified and filtered to produce a DC power supply that is used to drive the PWM output stage to the motor. The maximum output current to the motor is primarily due to the maximum current rating of the output switching transistors. However, maximum input current can sometimes be a preemptive limiting factor for single phase operation...

Bill, You did a great job summarizing VFD's. Maybe your information should be turned into a sticky for those needing to replace/upgrade their VFDs.

Question: Coring and hollowing large items can be tough on a motor and VFD. Is it worth spending a little more to get the next size up VFD to allow some overhead?

In other words, if you were selecting a WEG VFD for a stubby 750 lathe with 2HP motor then would you pay the extra $46 for a 3HP model or get the 2HP model?

​

CFW500 B10P0B2DB20
WEG CFW500 AC Drive, 3HP, 230V 1 PH/3 PH Input, 230V 3 PH Output, 10FLA, includes Braking Transistor, IP20
$324.00

CFW500B07P3B2DB20
WEG CFW500 AC Drive, 2HP, 230V 1 PH/3 PH Input, 230V 3 PH Output, 7.3FLA, includes Braking Transistor, IP20
$278.00​

It's not my intention to pick on the VFD that was sent to Emiliano. I'm wanting to add a magnetic remote to my Vicmarc, but the VFD screen is no longer readable to change any input settings. Just wondering what to VFD buy when my old VFD finally dies. In other words, does it makes since to step up to the next higher model, or are quality VFDs from a company like WEG able to stand up to woodturning as spec'd?​

 

[Emiliano Achaval]

This thread is getting confusing to me.

Back in October 2018 a thread mentioned a new VFD for a Stubby 750 lathe to cure a (unexplained) problem. That VFD was "perfect", presumably meaning it solved whatever the lathe's problem was. Was that the $1800 VFD?

Now the same (?) Stubby 750 lathe is having issues diagnosed as a bad motor so a new $500 WEG motor was ordered (which can't be returned). And yet still another new motor and VFD are soon to arrive along with a new Stubby 1000 lathe.

What is this about unlocking P0009? If a parameter is locked on a manufacturer supplied VFD it may be locked for a reason, most likely safety. In my experience locked parameters usually are password protected and without the password you may be out of luck (Grizzly does that with their lathe VFD's, even their tech support can't unlock their VFD's).

Emiliano, I fully understand your isolation on Maui with few options to help diagnose electrical issues. I find it surprising the lathe maker has not been more involved in helping you, this process of replacing components until you find the real issue can get expensive. IMO, it doesn't speak well for the manufacture

Good things to check, especially the pulley slipping. Some pulleys have a keyway and the key could have fallen out or even sheared. More likely it would be a setscrew (grub screw if you live in Oz) that has loosened due to vibration. Thanks for looking for the obvious first. We may have prematurely jumped to conclusions.

A slipping belt usually squeals and for sure will get the pulley hot.

So what did the VFD say when the spindle stopped? I don't think that looking at the VFD would tell you much if anything since it is just outputting a frequency, but doesn't know what the motor is doing. Maybe it's the motor pulley that is slipping, but the motor is running at the commanded speed. if you haven't done it already look at the motor shaft while holding the spindle so it doesn't turn.

It started giving me an error, I would have to turn it off and on again. He could tell I was going to stall it by seeing I had reached something, some output number. As you can see, I have no idea about vfd's... I have not checked that the grub screw is there, embarrassed to say it... Belt is not slipping. Off to the airport to pick up Hawaiian Calabash master David Chung. I will check that today

 

[Bill Boehme]

Bill, You did a great job summarizing VFD's. Maybe your information should be turned into a sticky for those needing to replace/upgrade their VFDs.

Question: Coring and hollowing large items can be tough on a motor and VFD. Is it worth spending a little more to get the next size up VFD to allow some overhead?

In other words, if you were selecting a WEG VFD for a stubby 750 lathe with 2HP motor then would you pay the extra $46 for a 3HP model or get the 2HP model?

​

CFW500 B10P0B2DB20
WEG CFW500 AC Drive, 3HP, 230V 1 PH/3 PH Input, 230V 3 PH Output, 10FLA, includes Braking Transistor, IP20
$324.00

CFW500B07P3B2DB20
WEG CFW500 AC Drive, 2HP, 230V 1 PH/3 PH Input, 230V 3 PH Output, 7.3FLA, includes Braking Transistor, IP20
$278.00​

It's not my intention to pick on the VFD that was sent to Emiliano. I'm wanting to add a magnetic remote to my Vicmarc, but the VFD screen is no longer readable to change any input settings. Just wondering what to VFD buy when my old VFD finally dies. In other words, does it makes since to step up to the next higher model, or are quality VFDs from a company like WEG able to stand up to woodturning as spec'd?​

See my post #45 above. The reason for derating a VFD would be when the operating manual says the inverter can be operated on single phase power, but it needs to be derated by a specified amount. I haven't checked the manual to see how much, but I would guess it is somewhere in the range of 35 to 50 percent. Otherwise, there isn't any good reason to use a higher HP inverter. So, in this situation, the 3 HP inverter is the next step up and it satisfies the derating requirement. My understanding from what I have gleaned from the posts and the manufacturer's data is that the 3 HP inverter was necessary for the 2 HP motor and single phase power.

It started giving me an error, I would have to turn it off and on again. He could tell I was going to stall it by seeing I had reached something, some output number. As you can see, I have no idea about vfd's... I have not checked that the grub screw is there, embarrassed to say it... Belt is not slipping. Off to the airport to pick up Hawaiian Calabash master David Chung. I will check that today

That's very interesting, but I don't know what to make of it. I suggest a methodical approach to isolating the problem:

• First remove the belt, then turn on the motor and see if you can stop it by grabbing the motor pulley.(wear gloves)
• If you can stop the pulley from turning look at the motor shaft to see if it is turning. If so, you have loose setscrews.
• Check the spindle pulleys for slipping. Grab the handwheel with your left hand and the pulley with your right. Try twisting in opposite directions to see if you can get the spindle pulley to slip.
• Check for friction in the motor and in the spindle.

 

[Bill Boehme]

He could tell I was going to stall it

It sounds more like a she than a he to me.

 

[Emiliano Achaval]

Good things to check, especially the pulley slipping. Some pulleys have a keyway and the key could have fallen out or even sheared. More likely it would be a setscrew (grub screw if you live in Oz) that has loosened due to vibration. Thanks for looking for the obvious first. We may have prematurely jumped to conclusions.

A slipping belt usually squeals and for sure will get the pulley hot.

So what did the VFD say when the spindle stopped? I don't think that looking at the VFD would tell you much if anything since it is just outputting a frequency, but doesn't know what the motor is doing. Maybe it's the motor pulley that is slipping, but the motor is running at the commanded speed. if you haven't done it already look at the motor shaft while holding the spindle so it doesn't turn.

Where else can you get so much help, so many talented people trying to help a fellow woodturner in distress? I'm happy to report that the Stubby's set screws are super tight. There is also a big "key" on the spindle, so it's nearly impossible for the pulleys to slip. Can you imagine if after all this I came back here to report that my problem was a loose set screw?! Wayne Omura and David Chung helped me look, we can 100% eliminate any belt and pulley cause for my torque problem.
I wish I could put to practice some of the great suggestions that folks here are offering. Problem is, some of them sound great, but on this rock in the middle of the Pacific, we do not have the resources available to mainland turners. Aloha to all.

 

[Emiliano Achaval]

This thread is getting confusing to me.

Back in October 2018 a thread mentioned a new VFD for a Stubby 750 lathe to cure a (unexplained) problem. That VFD was "perfect", presumably meaning it solved whatever the lathe's problem was. Was that the $1800 VFD?

Now the same (?) Stubby 750 lathe is having issues diagnosed as a bad motor so a new $500 WEG motor was ordered (which can't be returned). And yet still another new motor and VFD are soon to arrive along with a new Stubby 1000 lathe.

What is this about unlocking P0009? If a parameter is locked on a manufacturer supplied VFD it may be locked for a reason, most likely safety. In my experience locked parameters usually are password protected and without the password you may be out of luck (Grizzly does that with their lathe VFD's, even their tech support can't unlock their VFD's).

Emiliano, I fully understand your isolation on Maui with few options to help diagnose electrical issues. I find it surprising the lathe maker has not been more involved in helping you, this process of replacing components until you find the real issue can get expensive. IMO, it doesn't speak well for the manufacturer.

I bought the lathe from the American distributor, Bill Rubinstein of Stubby Lathe USA, about 14 years ago. Bill has since passed away. We do not have a USA dealer anymore. The owner of Omega lathes Rod Caddeye goes above the call of duty to help anybody that owns a Stubby, no matter who sold it to you. He can only do so much, he's running a business, not a charity or a welfare office. I like his customer service so much that I ordered a Stubby 1000. I will have 2 Stubby's in my shop, plus the Union Graduate. Rod is as confused as I am. I know this thread has gotten long, perhaps you missed where I wrote that Rod will send me a new VFD with a matching motor at no cost, he will add it to the pallet with the 1000. Try get any other Lathe company to do that for you. If I wrote in October 2018 that the VFD solved my problems, I lied, LOL. Thing is, works decently with small and or medium things, but anything over, say 12 or 14 inches, I can stall it easily.

 

[Emiliano Achaval]

Bill, You did a great job summarizing VFD's. Maybe your information should be turned into a sticky for those needing to replace/upgrade their VFDs.

Question: Coring and hollowing large items can be tough on a motor and VFD. Is it worth spending a little more to get the next size up VFD to allow some overhead?

In other words, if you were selecting a WEG VFD for a stubby 750 lathe with 2HP motor then would you pay the extra $46 for a 3HP model or get the 2HP model?

​

CFW500 B10P0B2DB20
WEG CFW500 AC Drive, 3HP, 230V 1 PH/3 PH Input, 230V 3 PH Output, 10FLA, includes Braking Transistor, IP20
$324.00

CFW500B07P3B2DB20
WEG CFW500 AC Drive, 2HP, 230V 1 PH/3 PH Input, 230V 3 PH Output, 7.3FLA, includes Braking Transistor, IP20
$278.00​

It's not my intention to pick on the VFD that was sent to Emiliano. I'm wanting to add a magnetic remote to my Vicmarc, but the VFD screen is no longer readable to change any input settings. Just wondering what to VFD buy when my old VFD finally dies. In other words, does it makes since to step up to the next higher model, or are quality VFDs from a company like WEG able to stand up to woodturning as spec'd?​

Karl, I totally understand. If you can buy a VFD and be able to wire it, you are much smarter than I am. I can send you a picture if you want to see how many connections I have, including the pigtail controller with a magnet, you need a cabinet, computer fan, the remote controller is not included, you will need that extra. If I had a Vicmarc, I would call the Vicmarc guy in Australia and buy the whole package, vfd and motor one time. Marco is a great guy. I buy direct from them and also from Vermec often. It is now cheaper than buying from the USA for us here in Hawaii. Even the shipping, because of the Jones Act, shipping from Australia to Hawaii is cheaper than Oakland-Hawaii. Thank the Unions and Congress for that. Looking back, my mistake was to just buy the VFD, I should have purchased the motor too. My new Stubby is coming with a 3HP motor. You can't ever have enough power on a lathe. I asked Rod for a 4 or 5 HP, but he talked me out of it, LOL. Unless you turn everyday like me, I would not worry about your vfd, I have seen some 20 plus-year-old Vicmarc lathes running strong... Aloha

 

[Bill Boehme]

Emiliano, I was busy yesterday, but I did have a few minutes to skim through the programming manual. It turns out that Karl is correct about P0009 being a "Read Only" parameter. It is called "torque current" and displays the motor current due to torque load as a percentage of the nameplate full load current. Its value can range from -1000% to +1000% of the nameplate FLC (full load current). About half of the parameters between P0001 and P0100 are "Read Only".

Emiliano, I'm thinking P0009 parameter is 'read only' which explains why it can't be set. The manual says this parameter indicates the torque developed by the motor in relation to the rated torque.....

I believe that you said Rod sent you a list of parameters that you need to set. Once you get the new motor you and Albert Einstein need to go through the tedious task of wading through the user manual and programming manual to get everything set up properly and verify that the parameters are correct. It's a good thing that you have an electrical engineer at your fingertips ... take good care of him. Anybody can set up a VFD and motor, but doing it so that optimal performance is achieved requires understanding all of the nuances involved.

 

[Mike Johnson]

Many of todays full featured VFD's have a very large selection of parameters to choose from, if you don't have a list of the parameters to program it can take hours scrolling through the options to end up with a functioning motor controller. The manual for the VFD usually has a list of all of the parameters that can programmed for use by the VFD, you will want to review the entire list and make a list of each parameter you need to program to speed up the process of selecting and activating each parameter. If the factory can provide the list of parameter settings used for your application that would be the fastest way to get it done. Several years ago I had a new facility coming on line and I worked on a project to set up VFD parameters for several hundred motors that needed to be set up for each type of application the motors were being used for. The learning curve to understanding all of the parameters and their function is time consuming, it is easier to know the application and all of the parameters that are needed for the application. The list of available parameters is different between manufacturers and how they are applied can be slightly different. The motor plate information and the voltage and frequency is the most important parameters to get right. A lathe motor application can involve a number of different parameters to allow for the various demands a woodturner subjects the motor to. For the project I worked on I used an excel spreadsheet and listed all of the available parameters and made a list of each size motor and the individual values off of each motor name plate and the facility voltage and frequency. A wood lathe can utilize braking, ramping, torque boost, inputs and outputs, time settings for braking and ramping, voltage loss, over voltage and under voltage, phase loss, over current and under current, start and stop functions, reset functions, curve settings for acceleration, deceleration, etc. etc.

 

[Bill Boehme]

Many of todays full featured VFD's have a very large selection of parameters to choose from, if you don't have a list of the parameters to program it can take hours scrolling through the options to end up with a functioning motor controller. The manual for the VFD usually has a list of all of the parameters that can programmed for use by the VFD, you will want to review the entire list and make a list of each parameter you need to program to speed up the process of selecting and activating each parameter. If the factory can provide the list of parameter settings used for your application that would be the fastest way to get it done. Several years ago I had a new facility coming on line and I worked on a project to set up VFD parameters for several hundred motors that needed to be set up for each type of application the motors were being used for. The learning curve to understanding all of the parameters and their function is time consuming, it is easier to know the application and all of the parameters that are needed for the application. The list of available parameters is different between manufacturers and how they are applied can be slightly different. The motor plate information and the voltage and frequency is the most important parameters to get right. A lathe motor application can involve a number of different parameters to allow for the various demands a woodturner subjects the motor to. For the project I worked on I used an excel spreadsheet and listed all of the available parameters and made a list of each size motor and the individual values off of each motor name plate and the facility voltage and frequency. A wood lathe can utilize braking, ramping, torque boost, inputs and outputs, time settings for braking and ramping, voltage loss, over voltage and under voltage, phase loss, over current and under current, start and stop functions, reset functions, curve settings for acceleration, deceleration, etc. etc.

... and if that isn't enough to hold your attention, you can work on setting parameters for creating fancy "S" curves for the ramp up and down functions. Also, don't forget that you can set it up so that it is able to talk to your computer.

 

[Mike Johnson]

And the one last thing you do not want to forget is to print a hard copy of the parameter settings and place it with your lathe or in the VFD manual so you can find it years down the road. You can archive the settings digitally but computers come and go and hard drives crash and you replace computers like a cheap pair of shoes these days, when you want to find the file it is usually on a computer hard drive that is no longer working or on a thump drive you can't find or somewhere in a stack of computer storage devices that will not work with the computer system you currently use.

 

[Emiliano Achaval]

Emiliano, I was busy yesterday, but I did have a few minutes to skim through the programming manual. It turns out that Karl is correct about P0009 being a "Read Only" parameter. It is called "torque current" and displays the motor current due to torque load as a percentage of the nameplate full load current. Its value can range from -1000% to +1000% of the nameplate FLC (full load current). About half of the parameters between P0001 and P0100 are "Read Only".



I believe that you said Rod sent you a list of parameters that you need to set. Once you get the new motor you and Albert Einstein need to go through the tedious task of wading through the user manual and programming manual to get everything set up properly and verify that the parameters are correct. It's a good thing that you have an electrical engineer at your fingertips ... take good care of him. Anybody can set up a VFD and motor, but doing it so that optimal performance is achieved requires understanding all of the nuances involved.

The numbers of parameters that need to be adjusted are surprisingly short. I now have a lot of respect for someone that can program a vfd... Thank you again Bill!

 

[Doug Rasmussen]

The numbers of parameters that need to be adjusted are surprisingly short. I now have a lot of respect for someone that can program a vfd... Thank you again Bill!

It shouldn't be a surprise. Most modern VFD's come with a default setting of parameters for general purpose use. I'm assuming WEG VFD's are that way too. There wouldn't be a situation where a VFD would barely operate a motor as we're seeing now and where a few parameter changes from default would make a major difference. This lathe is not a particularly demanding application.

My experience in re-programming VFD's has been mostly about simple issues like limiting the typical max frequency so the driven motor does not over speed. And acceleration ramp and braking changes. Those are just common sense issues easily understood by laymen. Very few VFD's would be sold to the general public if programming them bordered on rocket science.

 

[Bill Boehme]

There a lot of settings that you don't need such as those related to remote communications with a central computer in an industrial manufacturing environment. For our purpose we would use the settings that tell the software whether to use the control panel on the VFD or a separate control panel ... on the headstock for example. There are situations where auto tune works well ... such as a time invariant known load torque. Auto tune may not always result in optimal performance for a woodturning lathe where the load torque is all over the place.

While waiting for the new motor to arrive you could check out the switches, speed control potentiometer, and associated wiring. Look for intermittent connections while flexing the wiring or tapping on the switches and pot.

 

[Emiliano Achaval]

(continued from Chapter 1: Omega Lathes Stubby 750 VFD)

I replaced my old VFD on my Stubby 750 with a WEG CFW 500 V1 8X
I'm not happy with it. I had a club member engineer over, he tweaked it but still not working right. I do not have torque. What looks like the main torque parameter P0009 suppose to be adjustable to 1000%, but you can't adjust it. It's at ZERO. If anybody uses this unit, can you send me your parameters? I have another guy coming tomorrow to take a look. Also, Rod Caddeye from Omega lathes is going to a customers shop tomorrow with a Stubby and a WEG unit; he will send me the parameters too. I'm just trying to see what others are using. The WEG is an upgraded unit over what the Stubby comes from the factory. I wish I didn't upgrade; the other unit is proven, this one supposes to be way better, my engineer friend told me is worth the extra money. He recommends one unit that cost as much as a lathe, a top of the line lathe. Thanks in advance.

I'm happy to report that I finally have my Stubby 750 running full power. Rod Caddeye sent me a new VFD, brand: SEW. This unit is for a 3HP. My new WEG motor is 2HP. I have more torque than ever before! I can take full cuts with "the beast" my 3/4 Thompson V gouge. I did not have enough speed before either, now I can reach 2500 rpm with the high speed pulley. The WEG unit did not work, happy to send it back to Rod as soon as possible. Took my friend about 4 hours to install the new unit today. Needless to say, I'm super happy.

 

[Emiliano Achaval]

UPDATE!! I have not been happy with the torque of my lathe. This has been at least a one-year horror costly ordeal. Today, a friend suggested to open the cover and check to see how the wiring was done. Was done wrong! Lathe motors should be set up in Delta configuration, not in Star configuration!! Needless to say, this is all new to me, I have never heard Delta or Star before... To celebrate I put some massive Koa blanks on the Stubby. Life is back to normal.

 

[Mark Jundanian]

@Emiliano Achaval , you went from "super happy" to "not...happy" in one post. What happened? It looks like you had speed, but no torque? Any pictures of delta and star?

 

[john lucas]

I've never heard of Delta vs star configuration either. I looked it up. Wow guesss I know why I'm not an electronic engineer. That was deeper than I thought it would be but interesting to know. Here is one explanation I found. https://www.electricaltechnology.org/2014/09/comparison-between-star-and-delta-connections.html
Also found this which helps explain how it works.

View: https://www.youtube.com/watch?v=h89TTwlNnpY

 

[Tom Gall]

I've never heard of Delta vs star configuration either. I looked it up. Wow guesss I know why I'm not an electronic engineer. That was deeper than I thought it would be but interesting to know. Here is one explanation I found. https://www.electricaltechnology.org/2014/09/comparison-between-star-and-delta-connections.html
Also found this which helps explain how it works.

View: https://www.youtube.com/watch?v=h89TTwlNnpY

You're joking, right?!?! Duh!!! ..... at least I know how to push the on/off button. I'm so glad the VFD on my 1996 General 260 has never given me any problems.

 

[Emiliano Achaval]

@Emiliano Achaval , you went from "super happy" to "not...happy" in one post. What happened? It looks like you had speed, but no torque? Any pictures of delta and star?

I have pictures of both configurations. I will post them later today. I have been suffering from low torque syndrome for about a year. I had learn to live with it, adjusted my projects to it. It was affecting my work and my mental health. My friend, the engineer whom I call Einstein, has been demoted to sweeping floors and sanding, he needs to work off the almost $500 I have paid him. You think he learned in college about Delta and Star! He spent hours scratching his head sitting in front of the vfd, almost told him to go home to think once... At any rate, I have a 17 inch wide Koa blank, almost 50 pounds, waiting for me. I'm smiling again. Aloha

 

[Emiliano Achaval]

I've never heard of Delta vs star configuration either. I looked it up. Wow guesss I know why I'm not an electronic engineer. That was deeper than I thought it would be but interesting to know. Here is one explanation I found. https://www.electricaltechnology.org/2014/09/comparison-between-star-and-delta-connections.html
Also found this which helps explain how it works.

View: https://www.youtube.com/watch?v=h89TTwlNnpY

If you replace a motor, this is very important to know....

 

[Bill Boehme]

I mentioned this to Emiliano in a PM, but the term "star" apparently is a name used by the British and Aussies. In the USA we use the name "wye" or "Y" because it looks like the letter Y. I'm not biased, but I think that Y makes a lot more sense than star. Here's a picture ... you be the judge.



Delta gets its name from the Greek letter delta, Δ which it resembles. At least everybody is in agreement on that one. The three symbols represent the windings of the coils for each of the three electrical phases. If I'm not mistaken I believe that all of my Baldor inverters require the motor to use the wye configuration.

 

[Emiliano Achaval]

I agree that makes more sense to call it Y. I'm attaching the pictures of both configurations. Delta is the way to go for a lathe... I had a hard time sleeping last night, I could not wipe the smile off my face knowing my beloved Stubby is back to her normal self.

 

[Bill Boehme]

I've forgotten what the original problem was. I'm sure that it wasn't caused by the jumpers swapping around from a delta to a Y all by themselves. Seems like I recall that there was a question of whether the motor or the inverter went bad and you wound up replacing both. Are you still waiting on your Stubby 1000?

 

[Mark Jundanian]

So according to the video the delta configuration (or was it the star) has a huge starting amperage requirement. Is this a problem for you Emiliano?

 

[Don Wattenhofer]

Ordinarily that would be true, but when used with an inverter general purpose motors are susceptible to a number of problems if they aren't rated as either "inverter ready" or even better designed specifically for "inverter duty". The attached PDF file might be somewhat technical, but I think that the basic message still comes through: https://www.energy.gov/sites/prod/files/2014/04/f15/motor_tip_sheet14.pdf

I have read the attachment and would like to highlight one paragraph: {The insulation system on a 208/230-V motor is identical to that of a 460-V motor. Thus, voltage spikes produced by inverters on 208- or 230-V systems are unlikely to cause insulation damage at any cable length or drive carrier frequency.} Also I would note that the majority of 3 phase motors are dual voltage 230 / 460 volt. In my own shop I have 6 VFDs all of which I personally purchased and connected to ordinary 3 phase motors. The motors on my Lablond lathe and Bridgport mill have been around longer than VFDs without any apparent problems. As a side note the VFDs purchased in the last 10 years all cost under $300.00 and are still operating without problems as are the motors they are connected to.