# VFD choice for new mill



## luxige (Mar 1, 2020)

I asked for forum guidance in choosing a new mill in this thread here:








						Help me spend my money! It’s mill-shoppin’ time...
					

I’m planning to make my final decision this week and pull the trigger on a new mill.  I decided to buy new partly to avoid buying an endless project, partly because the vast majority of available used equipment in my area runs on industrial power and is too tall and/or heavy for me to deal with...




					www.hobby-machinist.com
				




And with the few molecules of remaining funds:


luxige said:


> ..... Some of that will have to go to a VFD unit right away. (I’ll be posting a new thread asking for help with that).



Well I was going to start a thread similar to the other one asking for advice about a VFD. But I have arrived at final choice, so I'll just throw it out there for a sanity check.

 Some of the posts on this forum mention the inexpensive import drives. Looking into those, there seem to be a lot of variations on three models: 'the white one', 'the gray one', and 'the even cheaper gray one'. The gray one is something I'd been looking at for a while, so I looked for some genuine reviews. In doing so, I came across youtuber Jeremy Fielding, who has lots of clear, if basic, tutorials on all things motor related. (Check out his channel!) He put a 'gray one' on his homemade bandsaw a while back. I put up a comment asking for his impressions since he's used it a couple of years. He was kind enough to reply right away and basically said "Meh." It's been rather finicky for him, and he seems like a pretty savvy guy to me. So, name brand for me.

I looked at Hitachi and Mitsubishi drives, then saw the Teco/Westinghouse L510. It looks like it will be easy to set up and use. I have downloaded the manual, which is huge but pretty easy to follow. Best of all, I found a YouTube series by user Clough42, who shows how he installed and programmed one for his 1HP Grizzly lathe. Very clear instruction, about 4 hrs of detailed content!
I'll be checking out the rest of his stuff.

Anyway, this is the unit I think I'll go with:








						AC Drive, 3hp, 230V, Single Phase,
					

VFD, 3hp, 230V, Single Phase, IP20, Medium Duty




					www.wolfautomation.com
				




Opinions welcomed.
Also, anybody have experience with that vendor?


----------



## RYAN S (Mar 1, 2020)

I went with wolf automation for three of my VFD’s  very good company, they stand behind their stuff, also the tech support line is nice. I went with the Lenze AC Tech for the three that I have. I really like the Lenze drives, very easy for me to program. The manual is straight forward. They are also made in America!! I called their tech line and had great help.
Ryan


----------



## luxige (Mar 1, 2020)

Thanks, Ryan! Wolf it is then.


----------



## toploader (Mar 2, 2020)

RYAN S said:


> I went with wolf automation for three of my VFD’s  very good company, they stand behind their stuff, also the tech support line is nice. I went with the Lenze AC Tech for the three that I have. I really like the Lenze drives, very easy for me to program. The manual is straight forward. They are also made in America!! I called their tech line and had great help.
> Ryan



I went this same route as well a couple years back. I’m happy with Wolf and Lenze drives.


----------



## machPete99 (Mar 2, 2020)

I have used the Hitachi  WJ200 series on a couple of machines (lathe and mill) and have been happy with them. I have not used the others so cannot directly compare. The lathe VFD has been running close to 3 years now, about 2 years on the mill. I have used large enough enclosures such that it does not require secondary fans, and that seems to have worked out ok.


----------



## stupoty (Mar 2, 2020)

I've had good luck with the HY vfd's , they have lasted well , I have got them a bit over rated for the motors they are running maybe thats a good thing 









						HY 4HP 3KW Spindle VFD 220V Converter Inverter Variable Frequency Drive+Cable➝EU  | eBay
					

Find many great new & used options and get the best deals for HY 4HP 3KW Spindle VFD 220V Converter Inverter Variable Frequency Drive+Cable➝EU at the best online prices at eBay! Free delivery for many products!



					www.ebay.co.uk


----------



## mksj (Mar 2, 2020)

The Lenze SMV are good reliable VFD's but quite expensive and  dated as to design and features, but a simple install on the mill. They will work fine for a mill, but for a lathe they would not be recommended them because of limited programming parameters and it does not support an external braking resistor. The Teco L510 offers all the same features at less than 1/2 the price. The Automation Direct GS1 and GS2 drives are also becoming quite dated, you want to be able to run the motor in sensorless vector mode, which is only supported by the GS3 and GS4 models, which work well but pricey.  HY drives are inexpensive, they have a high DOA up to 25%, the manuals are very poor, there are numerous iterations of the drives some lacking many features, no technical support/warranty, etc. I consider them a disposable drive which may or may not work for you. Looking at the technical end of the internals, many individuals that have worked on VFDs say the internals do not support their ratings.  If they work for the first few hours then they probably will continue to work. They have many models running single phase up to 10 Hp, but on difficult loads they often go up in smoke so advisable to up size the VFD for the load you plan to use.

The Teco's would be my first suggestion based on reliable electronics, reasonable price, ease of install and decent technical support. Their manuals are less intimidating then others and tend to be well written. The L510 is the entry model which is very reasonably priced, the E510 is a bit more full featured and available in a NEMA 1 or 4X enclosure, the latter being sealed and with a power disconnect switch. The Hitachi WJ200 is a mid cost reliable VFD, they work very well, but the manuals can be overwhelming. I have already posted quite a bit of information on the WJ200's for both lathes and mills, so should be an easy setup. There is the Fuji and Mitsubishi VFD's in a range of models, they all work well similar to the WJ200, but manuals are similar to the Hitachi in complexity, so a bit more challenging for a novice install. Cost wise they are in the same range as the WJ200. Vendors for VFD's, the most common ones that I use are Drives Warehouse,  Wolf Automation and State Motors and Controls. I purchase a lot of ancillary switches and controls from from Automation Direct, but not their VFD drives. In other discussions with VFD technicians, it was mentioned that the Automation Direct drives were sourced from other manufactures and rebranded. The support from Automation Direct is very good, and they sell good quality parts.


----------



## Aaron_W (Mar 2, 2020)

I went through Wolf as well. If you email their tech services they will help you choose a VFD specific to your use.

I was looking at a Teco 510, but they suggested a Lenze or Fuji for a mill, something over my head about how they work at low speeds which improves torque. I went with the Fuji which was the cheaper of the two by about $100.

Edit, mksj posted while I was typing, I will second his comments about the manual. The Fuji manual is rather intimidating, although after some help here that intimidation was reduced and while complicated and dry, honestly if you follow it step by step it is actually well written and easy to follow, just very technical.


----------



## cathead (Mar 2, 2020)

My Teco FM50, now a few years old, has worked flawlessly.


----------



## mksj (Mar 2, 2020)

Sensorless Vector mode helps drive motors better at lower speeds, typically below 30 Hz. It is a form of motor feedback that the VFD reads the motor speed/operating conditions and then adjusts the drive to optimize performance. The implementation of the software control varies, the L510 I have heard reported has this feature, but the implementation is not as good as more expensive models. Still it works well for general use, more expensive VFD's will give you better low speed control and torque. The Fuji are very popular with Wolf Automation, they seem to be pushing them a lot. They are good solid VFD's, but take a little more work in regards to getting through the manual. A mill is an easy setup anyway you go, I prefer to go with 3 wire control where you use momentary start and stop buttons, and then a separate selector for Forward/Reverse. I recently did a system for a PM-935 with this setup using the WJ200, but works the same with other VFDs.


----------



## luxige (Mar 3, 2020)

Wow, tons of good info!
Thanks, everyone for taking the time to respond. Sorry I haven’t had time to reply individually, but it’s all been helpful.

I will stick with the L510 since I have a basic grasp on what it can do, and how to tweak it. It can run as low as 6Hz and has SLV mode and built in braking.
The WJ200 would probably be my second choice.

I have a control box that had been retrofitted to my lathe, with six Allen-Bradley switches/10K pot. That will be perfect to control a power-latched contactor and three-wire low V control as mksj suggests above. The lathe also provides a circuit breaker, fuse blocks and the contactor, which has a 24V coil and a transformer, so there will be no high voltage current in the control box. I will also add an EMI filter, and an auxiliary cooling fan for the machine motor which will run when the motor is operating at a low speed and prone to overheating.

Finally managed to add a photo. I can only get it in as a thumbnail link.
Anyway, I'll remove the 'spindle' and 'pump' stickers and swap the On/Off switch and Start pushbutton.  So the top row will be spindle controls (speed, direction, on/off).
The bottom row will control the contactor which powers and shuts down the whole thing.


----------



## luxige (Mar 6, 2020)

Here's the plan:


----------



## luxige (Mar 6, 2020)

120AC will supply a standard power strip, which will later run the power feeds, as well as a small 12VDC supply. The 12V will run an auxiliary cooling fan to boost airflow through the big motor when operating at lower speeds.
120V also runs through a two-leg C/B to a stepdown transformer which runs the 24VAC contactor coil. That supply runs through a Stop pushbutton and E Stop switch, then the momentary Start pushbutton. When the coil is energized, an aux leg of the contactor keeps the coil latched on as long as power is supplied. A power loss will shut everything down regardless of switch positions. 
Two of the three power legs of the contactor control 240V power to the VFD (passing through two fast acting fuses and an EMI input filter). The same 240V/30A circuit will have a branch with an outlet for lathe power, since only one machine at a time will be used.
The VFD three phase outputs will have ferrite chokes to help reduce radiated EMI. The VFD's low voltage terminals include a relay to control the aux cooling fan, On/Off and Fwd/Rev switches, and a 5k potentiometer for speed control.


----------



## mksj (Mar 7, 2020)

Not the correct way to hookup the VFD, they are not designed to be turned on/off frequently to run a machine. You want a main power switch to energize the VFD, you can use a contactor but it is not needed. When you power down a VFD you should wait at least 5 minutes before powering it back up. Frequent on/off powering will damage the VFD because the current inrush relay/resistor will fail.

You use 3 wire control to run the VFD, check the manual, it uses 3 input terminals. Power loss or on power up wil stop the machine. E-Stop breaks the connections to the control inputs, but you will still will get electronic braking.


----------



## tazzat (Mar 7, 2020)

replace the for/rev whit a 3 Position  button and use this for start stop/for/rev.


----------



## luxige (Mar 7, 2020)

mksj said:


> Not the correct way to hookup the VFD, they are not designed to be turned on/off frequently to run a machine. You want a main power switch to energize the VFD, you can use a contactor but it is not needed. When you power down a VFD you should wait at least 5 minutes before powering it back up. Frequent on/off powering will damage the VFD because the current inrush relay/resistor will fail.
> 
> You use 3 wire control to run the VFD, check the manual, it uses 3 input terminals. Power loss or on power up wil stop the machine. E-Stop breaks the connections to the control inputs, but you will still will get electronic braking.



Thanks for taking the time to look it over, I appreciate your input!

We’re on the same page here, but I wasn’t clear about how I will use the controls. Rest assured, I won’t be turning the VFD on and off repeatedly, just at the beginning and end of a session. I’d rather have switch labels that say something like Power and Shutdown, but I couldn’t find any. Maybe I’ll try to make my own. My Start/Stop buttons *will not *be used as motor controls though.

True, a contactor is not required in the manual, but suggested. And the VFD does have built in power-off protection. For anyone wondering, the manual says a circuit breaker may not be used to turn the VFD on and off. So I could either buy a high voltage power switch, or use the contactor that’s already sitting on my shelf for the low price of $free.99. And, I get an additional layer of protection.

3-wire control is correct, and that is shown on the left side of my diagram. The On/Off and Fwd/Rev switches connect COM to S1 or S2, with S1 and S2 programmed for Fwd/Stop and Rev/Stop functions. And the Speed knob controls speed.

You make a great point about the benefit of having electronic braking during an emergency stop.
Initally, I was going to put the E Stop switch in series with the 3-wire circuit, but I realized that if the switch was reset (either thoughtlessly or accidentally) the VFD would see it as a Run command and start running the motor. You’d have to remember to turn the motor control Off before resetting the E Stop. Moving the E Stop to the contactor coil protects the user against a brain fart in the heat of the moment.
However! I had not considered the issue of braking. It would definitely be better to keep that capability during an emergency stop. Looking at the manual again, I see a Rapid Stop function that can be programmed for one of the switch inputs. I’ll try that out when I bench test this rig, putting the E Stop on input S2. If I get that to work (keeping protection against unintended start), that would be the way to go, so I thank you in advance.


----------



## luxige (Mar 7, 2020)

tazzat said:


> replace the for/rev whit a 3 Position  button and use this for start stop/for/rev.



Thanks for your reply!
The three position switch is more common I guess, but if you look at the way I have my two switches set up (see the left side of my diagram), they do exactly the same thing. That’s just the way I think - in steps. 1. Choose direction. 2. Turn machine on/off.

For more detail, see my reply to mksj above.


----------



## tazzat (Mar 7, 2020)

your panel have a start button for spindel .. the same button is stop spindel and it say start only? if ist only using it ist no problem,,


----------



## mksj (Mar 7, 2020)

Three wire control works with momentary switches, you use your start and stop buttons to control the on/off. the reverse is a sustained switch. If running you can flip the direction switch and the mill motor will change direction w/o operating the stop/start button. Any interruption of power it goes to the stop mode. E-Stop use a NC switch block that goes open when engaged and interupts the COM input, you can also have a second E-Stop NO switch blocks the goes closed when pressed and can connect to S4 programmed as an emergency stop.  The contactor is sometimes used for the power on, but requires a separate on/off switch, a transformer that is always on and additional wiring. Most VFD's have an option to not allow a VFD to restart when powered up. A 30A rotary power switch can be purchased for around $30.  The manuals show all kinds additional accessories  not really needed. You do not need to add a lot of complexity on a mill for basic operation. 

On some of the systems I build I do more complex systems with auto-tap auto-stop/start based on quill position, maintains same direction in back gear, etc. This requires more complexity, but for basic systems I use the 3 wire as described.


----------



## luxige (Mar 7, 2020)

mksj said:


> Three wire control works with momentary switches, you use your start and stop buttons to control the on/off. the reverse is a sustained switch. If running you can flip the direction switch and the mill motor will change direction w/o operating the stop/start button. Any interruption of power it goes to the stop mode. E-Stop use a NC switch block that goes open when engaged and interupts the COM input, you can also have a second E-Stop NO switch blocks the goes closed when pressed and can connect to S4 programmed as an emergency stop.  The contactor is sometimes used for the power on, but requires a separate on/off switch, a transformer that is always on and additional wiring. Most VFD's have an option to not allow a VFD to restart when powered up. A 30A rotary power switch can be purchased for around $30.  The manuals show all kinds additional accessories  not really needed. You do not need to add a lot of complexity on a mill for basic operation.
> 
> On some of the systems I build I do more complex systems with auto-tap auto-stop/start based on quill position, maintains same direction in back gear, etc. This requires more complexity, but for basic systems I use the 3 wire as described.
> 
> View attachment 316078



Okay, thanks again!
I now have a fuller understanding of 3-wire inputs. And you’ve driven me to dive into the manual some more.

It looks like you pulled that diagram from a Teco manual. For the L510, that’s page 4-35. Describes how 3-wire works.
So it looks like I’m actually talking about 2-wire, Mode1 as on page 4-33. Honestly I think the 2-wire appeals more to my primitive caveman brain. But I promise, when I bench test the wiring, I’ll try out the 3-wire method and see how I like it.

Start switch v. contactor? I compare it like this:

Start switch
- works good
- don’t have one, would cost me:
- $30 (that’s two dozen oysters around here)

Contactor
- works good too
- already have it
- Free! (trump card)

The VFD will be here in a few days. I’ll update when I wire up a test.


----------



## luxige (Mar 12, 2020)

The Teco VFD arrived today. I have test wiring set up except for a source of 240 V. Just haven't had time to install the breaker.
I do have the contactor control buttons wired and tested their operation; that's all set. The buttons connect to the three pigtails at the top of the photo.
You may have noticed an unused power leg on the contactor. I have an old bathroom vent fan leftover from a remodel. I think I'll use it to supply cooling airflow to the system. The contactor will run the fan anytime the VFD is powered on.


----------



## Eddyde (Mar 12, 2020)

Here is how I wired up my mill with momentary controls:








						Wiring A Vfd To A Momentary Pushbutton Switch (update)
					

I just installed a Teco L510 VFD to run my mill. I wanted to use a momentary pushbutton "Forward", "Reverse" and "Stop" switch, However, the VFD requires the switch status to be constant, so  I designed a simple circuit using two latching DPDT relays to achieve the correct interface. I also made...




					www.hobby-machinist.com


----------



## luxige (Mar 12, 2020)

Thanks!


----------

