# Another Vfd Thread



## Deerslayer (Dec 30, 2015)

Ok I have been searching and get bits and pieces of ideas on this subject.  However my searching had left me intrigued with questions. 

Is there a VFD for dummies thread I'm missing somewhere??

I need/want a 3-5 hp VFD motor setup for a lathe, I currently have nothing so I am looking for ideas and input. 

First question, I keep seeing some references to using 240 AC to power a VFD with a three phase motor? Does this not require a phase converter?


----------



## den-den (Dec 30, 2015)

[QUOTE="Deerslayer, 
I need/want a 3-5 hp VFD motor setup for a lathe, I currently have nothing so I am looking for ideas and input.

First question, I keep seeing some references to using 240 AC to power a VFD with a three phase motor? Does this not require a phase converter?[/QUOTE]

The VFD is a phase converter - (If you purchase one made for single phase input).  You will need a three phase motor rated for 240v (most are but a few are only 480v).
3 hp output with single phase input is readily available, the selection gets tricky for larger HP ratings


----------



## djfer75 (Dec 30, 2015)

On my lathe I run a 5hp 3 phase motor off a yaskawa vfd cimr-vuba0018faa with a 240v single phase input and a 240v 3 phase output and it runs great


----------



## Deerslayer (Dec 30, 2015)

djfer75 said:


> On my lathe I run a 5hp 3 phase motor off a yaskawa vfd cimr-vuba0018faa with a 240v single phase input and a 240v 3 phase output and it runs great




Looks like the yaskawa may be out of budget for this project. 

Anyone have experience with huan yang Chinese VFD? I know you get what you pay for and I hate buying Chinese, however this isn't gonna be a daily use machine, more just hobby use. 

I am still fascinated you can put a three phase motor on single phase power via a VFD.


----------



## mksj (Dec 31, 2015)

VFDs convert the incoming power to 3 phase, and require a 3 phase motor. They rectify the incoming AC (convert to DC)  and then convert it back to a finely chopped up wave of AC which can be adjusted to give you the adjustable speed output. "Pulse-width modulation (PWM) VFDs are most commonly used in industry because of excellent input power factor due to fixed DC bus voltage, no motor cogging, higher efficiencies, and lower cost. A PWM VFD uses a series of voltage pulses of different lengths to simulate a sinusoidal wave".

The rating of the VFD is dependent on if it is rated for single phase input, 3 phase input or both. The break point for single phase input VFDs is around 3 Hp, there are some rated at 5 Hp single phase input, but it gets pricey above 3 Hp. Many 3 phase VFDs can be run off of single phase but they need to be over sized by ~1.8 on the Hp rating. So to run a 5 Hp three phase motor you would need something like a 10 Hp three phase VFD if run off of single phase.  The eBay specials, work for some people and not others, if you want electronic braking, many of these are missing the braking module for an external braking resistor. So hit or miss. Above 3 Hp I think the recommendation would be to go with a RPC.

If you can make it with a 3 Hp 3 phase motor, you have a wider selection of VFDs that run off of single phase input 240VAC. They will run a little over $300, some have more features than others, they are all good units.
Examples:
Teco, N3-203-CS-U  http://dealerselectric.com/N3-203-CS-U.asp
Hitachi WJ200-022SF  https://www.driveswarehouse.com/p-2527-wj200-022sf.aspx
Automation Direct GS2 or GS3  GS2-23P0 http://www.automationdirect.com/adc/Shopping/Catalog/Drives/GS2_(115_-z-_230_-z-_460_-z-_575_VAC_V-z-Hz_Control)/GS2_Drive_Units_(115_-z-_230_-z-_460_-z-_575_VAC)/GS2-23P0
http://www.automationdirect.com/adc/Shopping/Catalog/Drives/DURApulse_-_GS3_(230_-z-_460_VAC_Sensorless_Vector_Control)/DURApulse_-_GS3_Drive_Units_(230_-z-_460_VAC_SLV)/GS3-23P0


----------



## kingmt01 (Dec 31, 2015)

I'm pretty new to VFDs do I don't have much knowledge with them. I got mine of eBay for $100. I like the seller. He was very helpful in information before the sale. It does have some breaking with no resistor installed. It is a 2.2Kw. I've always been told not to oversize your VFD it's rating has to match your motor.


----------



## Deerslayer (Dec 31, 2015)

kingmt01 said:


> I'm pretty new to VFDs do I don't have much knowledge with them. I got mine of eBay for $100. I like the seller. He was very helpful in information before the sale. It does have some breaking with no resistor installed. It is a 2.2Kw. I've always been told not to oversize your VFD it's rating has to match your motor.



What is your motor/vfd


----------



## mksj (Dec 31, 2015)

kingmt01 said:


> I've always been told not to oversize your VFD it's rating has to match your motor


This is not an issue if the motor parameters are set correctly. The older Huanyang VFDs do not have previsions for an external braking resistor, even though the terminals are there (circuitry is missing in some models). They may brake fine with a mill, but the large rotating mass in lathes is another story, there have been reports of failures in these VFDs.  

There is a newer generic Chinese VFD version that is available on eBay, which does have a braking module and appears to have better motor control parameters. The jury is still out on how well they work and reliability, but I would get the newer version if you go this route.
http://www.ebay.com/itm/1-5KW-2hp-7...386082?hash=item541689dae2:g:XJ8AAOSw0vBUkjm0
http://www.ebay.com/itm/New-2-2kw-F...694858?hash=item2a4d312d0a:g:zr0AAOSwDNdVgocx


----------



## kingmt01 (Dec 31, 2015)

Deerslayer said:


> What is your motor/vfd



Here is where I posted a link to both the eBay sale & a manual.

mksj
No doubt about the VFD your talking about. I don't use a resistor for breaking. Mine is set very low & only set to break for half a second. It doesn't kick in until the spindle is almost stopped. Mine steps down over 3 seconds then breaks for one second just to stop the last few seconds of it winding down. It isn't realy noticeable. I had the breaking set higher but the VFD screams in a really high pitch when it is. I found that (iirc) .5% is enough to stop it & that is where it is for now. If I get smarter about it later on I might try some changes.


----------



## joshua43214 (Dec 31, 2015)

If you hunt around a lot for VFD threads, you will come across some pretty bad horror stories from people buying discount VFD's. The issues come up with the manual being impossible to use and the VFD ends up sitting around for weeks or even months while the buyer tries to figure out how to get it set up properly. Since every set up is slightly different, there is no cookie cutter solution.

Unless you are prepared to potentially have to spend hours of time over several week or even months, I would advise you pay the extra for a unit from Taiwan or Japan that comes with a manual in actual English and support to back it up. Like has already been stated, you will get features with a better VFD that you will probably be happy to have down the road/.
I would suggest that you contact Automation Direct
http://www.automationdirect.com/adc...hTMFB5RweVdKlnUg-FXak35DMFClK6mFrHxoCmQzw_wcB
Call the 800 number and ask for a person to help you choose the right VFD. You will get the straight dope from a professional on both what motor to buy and what VFD to go with it. Make sure you are at your computer when you call, the helpful person will probably walk you to the different options on their website.
This place
http://dealerselectric.com/
has about the best prices for motors I have found. They carry a lot of new old stock and sell some of at a pretty serious discount. They also sell motor/VFD packages, but they don't have anything in your size range in stock right now.


----------



## Deerslayer (Dec 31, 2015)

kingmt01 said:


> Here is where I posted a link to both the eBay sale & a manual.
> 
> mksj
> No doubt about the VFD your talking about. I don't use a resistor for breaking. Mine is set very low & only set to break for half a second. It doesn't kick in until the spindle is almost stopped. Mine steps down over 3 seconds then breaks for one second just to stop the last few seconds of it winding down. It isn't realy noticeable. I had the breaking set higher but the VFD screams in a really high pitch when it is. I found that (iirc) .5% is enough to stop it & that is where it is for now. If I get smarter about it later on I might try some changes.



I don't see your link?


----------



## kingmt01 (Jan 1, 2016)

Sorry. I was half asleep. I guess I didn't post it.

http://www.hobby-machinist.com/threads/2-2kw-vfd-3-phase-3hp-motor.41077/

It is in pretty simple English. Not knowing anything about it I was able to get it set up. I bet most people's horror stories are actually from not knowing what they are doing. Each time I read through the manual things become a little more clear. 

You don't always get what you pay for. Just because you pay more doesn't make it better.


----------



## HMF (Jan 1, 2016)

In the Electrical Knowledge Base above this forum we have:

http://www.hobby-machinist.com/library-articles/how-to-wire-a-vfd-to-your-machine.26/


----------



## alloy (Jan 1, 2016)

I completely agree with joshua43214 about Automation Direct VFD's.

I bought 2 Hitachi VFD's fr my Bridgeport, one for the spindle motor, and one for  the power feed.  I took them both out to Jim's Dawson's place and he worked on them for a decent amount of time working on setting them up.  I looked pretty hard at the instructions and being totally electrically challenged I couldn't make had or tails of the manual.

When I got the E-head for my newest mill I had to buy a DuraPulse sensor-less vector VFD to run the Baldor Super-E motor.  I was at Jim's and with reading the well written manual and after asking a few questions Jim answered I was able to set up the VFD, all except one thing.   I bought a braking resistor and no matter what we did braking wouldn't work.

I finally had to call Automation and the tech knew exactly what the problem was.  I looked through the entire manual page by page  for every mention on braking and there was nothing about turning on braking with a resistor.  As it turns out it was labeled "overload protection".  The tech was fast and spoke english.

On my Bridgeport the Hitachi VFD for the spindle motor literally blew up.  A big fireball shot out the side of it, and I was stuck.  Jim had a VFD from Automation and I got it from him and later replaced it.

Yes the VFD's from Automation cost more, but in my humble opinion they are worth it.


----------



## 95ttoplt1 (Jan 8, 2016)

I'm new so be gentle, and I'm certainly not trying to hijack.

What VFD from automation direct are you guys using? I was just looking for one for a 1.5hp J head BP. Seemed like the GS2 for 2 hp was $250, seems very competitive with a RPC??

Am I missing something? All the searching turns up that VFD's are uber expensive. That seems very competitive with the RPC's, with lots of benefits.

Oh, what is resistor brakeing?


----------



## JimDawson (Jan 8, 2016)

I am using the 3HP GS2 units, and Alloy has a 3 HP GS3 on his Kent.  We went with the GS3 on the Kent because it is direct drive, no change belts or verispeed, so better low end torque with the vector drive GS 3 unit.

A breaking resistor is attached to the VFD to dissipate power during breaking, it allows faster stops.  When breaking, the motor becomes a generator and feeds power back into the VFD.  The resistor gives the power somewhere to go.  Most VFDs will adsorb some power without tripping out, but you can't stop as fast as with a breaking resistor installed.  My 3 HP mill for example takes about 4 seconds to stop without the resistor installed, but will stop in about 1.5 seconds with the resistor.


----------



## alloy (Jan 8, 2016)

I'm no expert, but benefits of a VFD over an RPC are fingertip speed control, and more energy efficient.  You don' have a motor turning all the time soaking up power even when the spindle isn't turning.  And the added benefit of braking.

You can get a breaking resistor for less then Automation charges.  I've got both of my resistors off Aliexpress for 1/3 the price.  You just need to read the specs on the VFD and find the correct resistor for that unit.


----------



## mksj (Jan 8, 2016)

95ttoplt1 said:


> Am I missing something? All the searching turns up that VFD's are uber expensive. That seems very competitive with the RPC's, with lots of benefits.


There are really inexpensive VFDs, direct from China, but it is hard to know what you are getting and what recourse you have if it doesn't work or fails.  The price and size of VFDs have come down, and they do have many programmable features, the break point is probably around 3Hp on a VFD vs. store bought RPC. If you have a lot of 3 phase machines than an RPC would be more cost effective. It you need variable speed on a particular machine, it still doesn't rule our running a VFD off of your RPC.

Braking resistors are available on eBay for about $20 for up to a 500W resistor.


----------



## 95ttoplt1 (Jan 8, 2016)

Thanks, that clears up a lot of nagging questions.


----------



## alloy (Jan 8, 2016)

Forgot to mention an added feature of the GS3 is a simulated tachometer output.  Since I have no vari speed or pulleys to change belts for speed, a tach is mandatory for my mill.  

It took a little time setting up, but we have the tach reading within about 10 RPM of the actual spindle speed.


----------



## Eddyde (Jan 8, 2016)




----------



## HMF (Jan 9, 2016)

95ttoplt1 said:


> I'm new so be gentle, and I'm certainly not trying to hijack.
> 
> What VFD from automation direct are you guys using? I was just looking for one for a 1.5hp J head BP. Seemed like the GS2 for 2 hp was $250, seems very competitive with a RPC??
> 
> ...



This attached file is specific to a SB 9, but may help you.

Take a look and see if it is of any use to you.


----------



## modela (Jan 9, 2016)

By the way, I have a new, 2 hp 3-phase motor listed in the for sale items.  Thanks.


----------

