Another Vfd Thread

Deerslayer

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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?
 
[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
 
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
 
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.
 
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
 
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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.
 
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
 
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
 
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.
 
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.
 
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