# Another VFD Question



## JR49 (May 4, 2014)

On some of the You Tube vids about VFDs, they talk about getting a "2 HP rated VFD to use on a machine with a 1 HP 3 ph. motor", or a " 1 HP rated drive for a 1/2 or 3/4 HP motor. Are there any benefits to using a higher rated VFD than the 3 phase motor you will be using it on? Also, for you electrical guys out there, How about an outright Product recommendation. My lathe is a Logan 12 X 36 model #2557 VH, It uses a 1 HP 220V. 3 phase motor WHAT SAY YOU? thanks JR49


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## DMS (May 4, 2014)

I am running a 1.5kw VFD (2HP) on my 1.5HP mill. Not sure why folks recommend going so much oversize other than the "bigger is better" idea. The VFD I have actually has 2 ratings, depending on how you configure it. IIRC constant voltage and constant current modes had separate ratings, and the constant current mode was lower. For units that don't have both ratings, the "oversized" recommendation may be to account for running in constant current mode on a unit with a faceplate value rated for constant voltage.

As far as products, I am using a Hitachi WJ200-015SF http://www.hitachiacdrive.com/hitachi-wj200-series-wj200-015sf/ and I have been quite pleased with it. It's not the cheapest out there, but it had the features I wanted and cost was not crazy.


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## hvontres (May 4, 2014)

+1 on the Hitachi Wj-200 series. The thing to check when sizing a VFD is the *F*ull *L*oad *A*mps (FLA) on the nameplate for the motor. Then choose a VFD that is rated for at least that amount fo current. Ususaly that is the continous current rating. The Hitachi drives can supply up to 200% tourque on startup. One other thing to keep in mind is that VFD's can produce high voltage spikes that may damage the insulation on older motors. I added a three phase Reactor between the VFD and my mill to help reduce the spikes and protect the motor on my Bridgeport. Newer Motors tend to have new types of insulation that are designed to handle the spikes. If you decide to switch motors, look for an "Inverter Duty" one. Can you post a picture of the nameplate on the motor?

One other thing to keep in mind is that the power from the motor will reduce at low speeds. When using mechanical means (step pulley or Reeves drive) to change the speed, the motor is still running at the nominal speed and putting out 1HP. When you run the motor at 1/2 Speed, you are now only getting ~1/2 HP.

Ok, I just checked, and the 2557 has a variable speed drive. If it is still in good condition, I would reccomend using the VFD to generate 3 phase and using the original Variable speed setup to change speeds. This is what I have on my Brigeport J2 head and it works out really nice. One other thing I highly recomend is getting a braking resistor to help incrase the DC braking capabilities of the drive. On the bridgeport, I can stop the spindle in about 1.5 s, even at high speeed in backgear. And using a similar setup on my Clausing lathe, I can stop my 8" three jaw in about 5s. The Hitachi drives already have a dynamic braking unit built in, so adding the resistor is fairly simple. It's job is to make sure that the DC voltage inside the drive does not exceed the upper limit while braking, when the motor is actually acting like a generator. I am using a 500W 50 Ohm resistor that I got from e-bay for about $30.

Hope this helps.

PS: looks like you aren't too far away


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## sparkness (May 5, 2014)

JR49 said:


> On some of the You Tube vids about VFDs, they talk about getting a "2 HP rated VFD to use on a machine with a 1 HP 3 ph. motor", or a " 1 HP rated drive for a 1/2 or 3/4 HP motor. Are there any benefits to using a higher rated VFD than the 3 phase motor you will be using it on? Also, for you electrical guys out there, How about an outright Product recommendation. My lathe is a Logan 12 X 36 model #2557 VH, It uses a 1 HP 220V. 3 phase motor WHAT SAY YOU? thanks JR49




You can absolutely use a 1hp VFD for a 1Hp motor that is what it is rated for, no need to go to a larger model, you can use a larger vfd on a smaller motor . I have used several different brands, and each have some good features. automation direct and teco are the least expensive and easy to program. the automation direct 1hp does not have the ability to use a brake resistor but has some built in braking. you can display scaled rpm , amps. Mitsubishi is a bit of a pain to program but offers a lot of features. As hvontres stated using a larger motor is good for when you use  slow speed . on my 10" sheldon i have 1hp motor and vfd, I no longer use the back gear - just turn the knob on the vfd . I also run the motor up to 50% faster at times to get more rpm for finishing . Search the internet and you will find several places to get a good deal. I recommend buying new as apposed to used off of ebay because people selling used ones seem to ask way too much. here are a few sites which I have purchased from and had no problems. www.automationdirect.com www.dealerselectric.com www.factorymation.com


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## itsme_Bernie (May 5, 2014)

I met Dealers Electric guys at Cabin Fever once, and purchased a Teco for up to 1HP.  I love it.



Bernie


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## Smudgemo (May 7, 2014)

I have a Teco on my small horizontal mill & the Hitachi wj200 on my vertical. Both are great, but the Hitachi seems nicer. More robust?  I haven't seen any complaints for either. 


Sent from my iPhone using Tapatalk


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## jim18655 (May 7, 2014)

3 phase VFD connected to 1 phase may need to be derated depending on the model and size of the motor. You'll need to read your book to see if it applies to your setup. Most likely scenario would be to multiply the motor FLA (full load amps) by the square root of 3 (1.73) and use that answer to find the size of the drive you need.


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## hvontres (May 7, 2014)

jim18655 said:


> 3 phase VFD connected to 1 phase may need to be derated depending on the model and size of the motor. You'll need to read your book to see if it applies to your setup. Most likely scenario would be to multiply the motor FLA (full load amps) by the square root of 3 (1.73) and use that answer to find the size of the drive you need.



Or make sure that your VFD is set up for single phase input. The WJ-200's come as either SF (single phase) or LF models.


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## countryguy (May 8, 2014)

*Re: Some other considerations for VFD HP+1 formula : Another VFD Question*

And you'll find that many motors are now "inverter rated" which accounts to the VFD type tech. If your motor is not, you may want to do some research on many of the VFD settings and what your motor can accomodate. The comment about the older motors and burning out is out there. Many documents have pics showing this burn out event in the windings. With VFD driven it's so east to run the Hz up and see boosts in RPM. When you do this, another reason to possibly consider going over on theVFD side is that you will run the HP motor beyond it's design.    I did buy the 3HP for a 2HP Mill motor and 1HP lathe motor on my Shopmaster combo unit. LOVE that WJ200! Wowza! another thing I learned was the CT and VT ratios. 10:1/ 4:1 and the CT 1000:1 which I bought. as these motors are "paramatized" and delt HF blow's you can see how the "inverter rated" motors become almost a "must" consideration. (IMO). Also the IMax and RPM CT/VT roll off's when you push and pull the RPM's up & down may not do what you need. Just some comments while this is all fresh in my head from a week of VFD replacement on my Mill. What an adventure! 
CGout.


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## JR49 (May 10, 2014)

Thanks everyone for the great responses. As a total newbe I learn something from every response. hvontres, about your PS, unfortunately I'm still not that close yet. Although, thanks to this forum, I think I've learned enough to be able to "Power up" the lathe. BUT the total hip replacement surgery I had last month will keep me from running the electric to the lathe for at least a few more months, not to mention even getting on the floor to read the specs off the motor plate, so I get the correct VFD. However, even on crutches, I spend a lot of time out there  figuring things out and coming up with more questions for you guys. So thanks to all of you for keeping my recuperation, from getting boring, JR49


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## JR49 (May 10, 2014)

OK, after just finishing the post above, I convinced my wife to get on the floor and take a picture of the motor plate in my Logan lathe. I don't see a spec for "full load amps" or fla, but I'm sure someone will get some info from this pic (provided it shows up). I have no idea if this is the original motor or not, but it, and the lathe, seem to be in really good shape. Was made in 1969 I think. Wish me luck with the pic, thanks for any info you can get from it. JR49
	

		
			
		

		
	




	

		
			
		

		
	
(holly crap-I did it)
edit, if anyone needs that number at the very top right of the plate I can try again


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## JimDawson (May 10, 2014)

JR49 said:


> OK, after just finishing the post above, I convinced my wife to get on the floor and take a picture of the motor plate in my Logan lathe. I don't see a spec for "full load amps" or fla, but I'm sure someone will get some info from this pic (provided it shows up). I have no idea if this is the original motor or not, but it, and the lathe, seem to be in really good shape. Was made in 1969 I think. Wish me luck with the pic, thanks for any info you can get from it. JR49(holly crap-I did it)
> edit, if anyone needs that number at the very top right of the plate I can try again



3.6 amps @ 208-220


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## countryguy (May 10, 2014)

Looks like it is also 50hz or 60jz rated... I think.  Thus the 1700rpm at 60 and the 1400 at 50hz.    Being that I have been buying a new motor for my VFD this week, I did need to uncover some current settings as well.   The spec above seems almost like no load current?   But I was into 3 phase setups.   If you check the URL here  http://www.rm-electrical.com/publis...nical-information/motor-motor-current-charts/
there is a 15AMP FLC Rating typical on .75kw.    Anyway,  you could simply use a clamp on ammeter and read the current under no load and lathe load setups.     Then you know w/o a doubt!  

Enjoy oh and tell the misses thanks for the pics!  .    CG.


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## JimDawson (May 10, 2014)

countryguy said:


> Looks like it is also 50hz or 60jz rated... I think.  Thus the 1700rpm at 60 and the 1400 at 50hz.    Being that I have been buying a new motor for my VFD this week, I did need to uncover some current settings as well.   The spec above seems almost like no load current?   But I was into 3 phase setups.   If you check the URL here  http://www.rm-electrical.com/publis...nical-information/motor-motor-current-charts/
> there is a 15AMP FLC Rating typical on .75kw.    Anyway,  you could simply use a clamp on ammeter and read the current under no load and lathe load setups.     Then you know w/o a doubt!
> 
> Enjoy oh and tell the misses thanks for the pics!  .    CG.




A 1 HP, 3Ph @ 208-230V  NLA = 1.2, FLA = 3.6, and Locked Rotor Amps= 24


A 1 HP, 1Ph @ 230V NLA = 4.53, FLA = 6.8, and Locked Rotor Amps= 43


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## ddmunroe (Jun 11, 2014)

*Re: Another VFD Question (Advice please)*

Guys,
I'm looking to use a VFD to achieve "max torque at lower speeds" (max 1500 rpm) I do not need high rev's for this application
(Portable milling machine)

I want the lightest weight 3 phase motor, 6 poles 2-3 HP.

Correct me but if the combination of input frequency to voltage is "low to high then this is this a way to get increased torque at lower rpm's
If this is true that's good *but I don't want any motor burn out issues. 
This motor may run up to 8 hrs per day on end.

I'm also looking for a VFD product and supplier that can handle our 50 hertz 240 volt power (I'm located in Aus) 
Have looked but have not come across a vfd supplier here.

Am I on the right track,
Thank you
dd


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## JimDawson (Jun 11, 2014)

For the motor you are going to want an Inverter Duty motor.   These are designed to be able to run slow without overheating.  Light weight is a bit subjective, 2HP = 88 Lbs, 3HP = 108 Lbs.  These have an aluminum case.

Almost all VFDs will operate at 50 or 60 Hz.

I don't know what your budget is for this project, Siemens, SEW Eurodrive, and Allen Bradly are very available in Aus., but not cheap, as are Yasakawa, Mitsubishi, and others.  Automation Direct, in the USA, has excellent equipment and is in the mid price range, pretty sure they ship international.  On the low end there is always Ebay and a bunch of Asian equipment.

I think you are going in the right direction.


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## The Landshark (Jun 11, 2014)

For extended low speed running you will have overheating issues, i have had several problems with this in the past, i fitted a 240v enclosure fan to the fan shroud of a motor,
this kept it cool and have had no hassle since, this was done on a pump that an engineer decided to massively overspec, it was running at 5-8Hz to achieve the required delivery


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## ddmunroe (Jun 11, 2014)

JimDawson said:


> For the motor you are going to want an Inverter Duty motor.   These are designed to be able to run slow without overheating.  Light weight is a bit subjective, 2HP = 88 Lbs, 3HP = 108 Lbs.  These have an aluminum case.
> 
> Almost all VFDs will operate at 50 or 60 Hz.
> 
> ...



Hi Jim, I'll do more research for over here, many of my HB friends and machining contacts are buying things engineer related from the USA. Even with shipping it's cheaper. As far as the unit I won't go cheap cheap I prefer mid range pricing and get the most value per dollar, 88 lbs !! Jeez I hope not that heavy .... as I say I'll do some research if so so be it.




> For extended low speed running you will have overheating issues, i have had several problems with this in the past, i fitted a 240v enclosure fan to the fan shroud of a motor,
> this kept it cool and have had no hassle since, this was done on a pump that an engineer decided to massively overspec, it was running at 5-8Hz to achieve the required delivery




Hi did you get any temperature readings for when the motor was overheating before and after with the fan installed, good idea !
)
dd


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## ddmunroe (Jun 12, 2014)

JimDawson said:


> For the motor you are going to want an Inverter Duty motor.   These are designed to be able to run slow without overheating.  Light weight is a bit subjective, 2HP = 88 Lbs, 3HP = 108 Lbs.  These have an aluminum case.
> 
> Almost all VFDs will operate at 50 or 60 Hz.
> 
> ...



I had a specific question about low speed and high torque I found the answer on a Hitachi site Read below :http://dealerselectric.com/VFD_story.asp
*Variable frequency drives* now play an important part in major industry. Within the last 10 years they have been perfected to control and vary the speed of 3 phase electric motors. You may have heard them referred to as adjustable frequency drives, VFDs, and/or inverters.They serve many purposes, besides speed control. If you are a homeowner or hobbyist who purchased a lathe or milling machine with a 3 phase electric motor you are faced with a dilemma. You probably don’t have 3 phase power to operate it. Before variable frequency drives you had to purchase a rotary phase converter. That would effectively convert your single phase power to 3 phase power. Rotary phase converters are noisy and are not the ideal item you would want in your basement. Today these solid state variable frequency drives convert single phase power to 3 phase power silently and efficiently. They are available in 115 volts or 230 volts single phase input.Variable frequency drives have also played a major part in the growth of industry. They are known for reducing the consumption of electrical power. Many utility companies have offered and are still offering significant rebates when purchasing these items. They reduce the inrush current and have lowered the demand for more power. *These drives have also been improved and are available in sensorless vector models. These allow significant torque control, especially at lower speeds.*Many options are available for variable frequency drives. Dynamic braking as well as remote keypads are 2 of the most popular requests. When selecting a drive it is important to mention the application. They are available in constant torque or variable torque models.From home use to industrial use, variable frequency drives are actively used. In industry irrigation pumps as well as rock crushers are just 2 of the many areas of use. Home workshops have been set up in garages and basements throughout this country with the use of these drives.
So I need a VFD that is a  *sensorless vector model
*

- - - Updated - - -

As an example:
This model is close to what I'm looking for ...  still finding out ..... still researching
I prefer a Hitachi Model apparently a better quality product


*Teco*






 




 
*3 HP, 230 Volts, IP 20, Teco, JNEV-203-H1*
*Item#:* *JNEV-203-H1	* 
230 Volts 1 Phase Input, 230 Volts 3 Phase Output 
*Stock:* *20*
*HP	 :* *3**Enclosure	 :* *IP 20**Manufacturer	 :* *Teco**Input Voltage	 :* *230**Input Phase	 :* *1**Output Voltage	 :* *230**Output Phase	 :* *3**Condition	 :* *Factory New*

*Weight:* *5 lbs*

Our Price: * $215.00
*

*Qty:* 
  










Description



MOD. JNEV-203-H1
230V 1-PHASE INPUT/3-PHASE OUTPUT
*SENSORLESS VECTOR*
DRIVE AMPS 10.5 CONSTANT TORQUE
HEIGHT = 5.20
WIDTH = 4.65
DEPTH = 5.83
4 LBS.
IP 20 ENCLOSURE - FACTORY NEW WITH MANUFACTURERS WARRANTY


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## JimDawson (Jun 12, 2014)

ddmunroe said:


> I had a specific question about low speed and high torque I found the answer on a Hitachi site Read below :http://dealerselectric.com/VFD_story.asp
> *Variable frequency drives* now play an important part in major industry. Within the last 10 years they have been perfected to control and vary the speed of 3 phase electric motors. You may have heard them referred to as adjustable frequency drives, VFDs, and/or inverters.They serve many purposes, besides speed control. If you are a homeowner or hobbyist who purchased a lathe or milling machine with a 3 phase electric motor you are faced with a dilemma. You probably don’t have 3 phase power to operate it. Before variable frequency drives you had to purchase a rotary phase converter. That would effectively convert your single phase power to 3 phase power. Rotary phase converters are noisy and are not the ideal item you would want in your basement. Today these solid state variable frequency drives convert single phase power to 3 phase power silently and efficiently. They are available in 115 volts or 230 volts single phase input.Variable frequency drives have also played a major part in the growth of industry. They are known for reducing the consumption of electrical power. Many utility companies have offered and are still offering significant rebates when purchasing these items. They reduce the inrush current and have lowered the demand for more power. *These drives have also been improved and are available in sensorless vector models. These allow significant torque control, especially at lower speeds.*Many options are available for variable frequency drives. Dynamic braking as well as remote keypads are 2 of the most popular requests. When selecting a drive it is important to mention the application. They are available in constant torque or variable torque models.From home use to industrial use, variable frequency drives are actively used. In industry irrigation pumps as well as rock crushers are just 2 of the many areas of use. Home workshops have been set up in garages and basements throughout this country with the use of these drives.
> So I need a VFD that is a  *sensorless vector model
> *
> ...




I agree with your VFD Selection.

Another motor type that you might look into is a BrushLess DC (BLDC), also known as servo motors.  Maybe in the 1.5 to 2 Kw range.  They are a 3 phase motor with a permanent magnet rotor.  These have a much flatter torque curve and will produce almost 100% torque at 0 rpm.  Also the weight is about 1/2 that of a standard 3 phase motor of the same power.  I have seen these for sale in the USD$ 500 range with the controller, they may also be powered by a VFD.

There was a pretty good discussion of BLDC motors here http://www.hobby-machinist.com/showthread.php?t=23297&p=206307&viewfull=1#post206307


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## The Landshark (Jun 12, 2014)

ddmunroe said:


> Hi Jim, I'll do more research for over here, many of my HB friends and machining contacts are buying things engineer related from the USA. Even with shipping it's cheaper. As far as the unit I won't go cheap cheap I prefer mid range pricing and get the most value per dollar, 88 lbs !! Jeez I hope not that heavy .... as I say I'll do some research if so so be it.
> 
> 
> 
> ...



Hot enough that it burnt out before, it feels warm to the touch now but thats all


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## ddmunroe (Jun 12, 2014)

JimDawson said:


> I agree with your VFD Selection.
> 
> Another motor type that you might look into is a BrushLess DC (BLDC), also known as servo motors.  Maybe in the 1.5 to 2 Kw range.  They are a 3 phase motor with a permanent magnet rotor.  These have a much flatter torque curve and will produce almost 100% torque at 0 rpm.  Also the weight is about 1/2 that of a standard 3 phase motor of the same power.  I have seen these for sale in the USD$ 500 range with the controller, they may also be powered by a VFD.
> 
> There was a pretty good discussion of BLDC motors here http://www.hobby-machinist.com/showthread.php?t=23297&p=206307&viewfull=1#post206307



You mentioned servo motors, at the end of my research last night I started to read about them and saw as you mentioned they have lots of torque at 0-low revs EG 10 -50-100-500 rpm. This is more what I'm looking for. A servo motor vfd controlled 2 or 3 hp depending on the weight will go 2 or 3 hp. I need the lightest combination. One thing I need to learn more  about is this brushlless technology no brushes and computer controlled so what I said earlier is not correct. (servo motor vfd controlled) 
Q: Are all servo motors brushless ? therefore they have there own controller not through a vfd

I found a supplier here for servo motors and controllers called WEG. Do not know prices yet. 
Which company did you refer to in saying "500.00 for motor and controller.
May have got a few facts incorrect but as I say still grasping the concept and terminology.
For the record if a servo motor has brushes is it controlled by a VFD
If a servo motor is brushless is it controlled by a controller is this a fact
I am continuing my research
dd


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## John Hasler (Jun 12, 2014)

ddmunroe said:


> Q: Are all servo motors brushless ?
> dd



No.  A servomotor is just a motor  coupled with an encoder so that it can be used in a closed-loop control system.  Servomotors are often BLDC these days but they used to almost always be DC.  An induction motor coupled to an encoder and driven by a VFD could be used as a servomotor, though I would not recommend it for very low speed operation.


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## JimDawson (Jun 12, 2014)

ddmunroe said:


> You mentioned servo motors, at the end of my research last night I started to read about them and saw as you mentioned they have lots of torque at 0-low revs EG 10 -50-100-500 rpm. This is more what I'm looking for. A servo motor vfd controlled 2 or 3 hp depending on the weight will go 2 or 3 hp. I need the lightest combination. One thing I need to learn more  about is this brushlless technology no brushes and computer controlled so what I said earlier is not correct. (servo motor vfd controlled)
> Q: Are all servo motors brushless ? therefore they have there own controller not through a vfd
> 
> I found a supplier here for servo motors and controllers called WEG. Do not know prices yet.
> ...




I finally found the thread I was looking for.  http://www.hobby-machinist.com/showthread.php?t=23465&p=207824&viewfull=1#post207824  this thread references the Chinese servo motor I was talking about in the low price range.

Something like this might work for your application.


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## ddmunroe (Jun 12, 2014)

JimDawson said:


> I finally found the thread I was looking for.  http://www.hobby-machinist.com/showthread.php?t=23465&p=207824&viewfull=1#post207824  this thread references the Chinese servo motor I was talking about in the low price range.
> 
> Something like this might work for your application.


Much appreciated ... we're getting there.
T Y
dd


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## uncle harry (Jun 14, 2014)

sparkness said:


> You can absolutely use a 1hp VFD for a 1Hp motor that is what it is rated for, no need to go to a larger model, you can use a larger vfd on a smaller motor . I have used several different brands, and each have some good features. automation direct and teco are the least expensive and easy to program. the automation direct 1hp does not have the ability to use a brake resistor but has some built in braking. you can display scaled rpm , amps. Mitsubishi is a bit of a pain to program but offers a lot of features. As hvontres stated using a larger motor is good for when you use  slow speed . on my 10" sheldon i have 1hp motor and vfd, I no longer use the back gear - just turn the knob on the vfd . I also run the motor up to 50% faster at times to get more rpm for finishing . Search the internet and you will find several places to get a good deal. I recommend buying new as apposed to used off of ebay because people selling used ones seem to ask way too much. here are a few sites which I have purchased from and had no problems. www.automationdirect.com www.dealerselectric.com www.factorymation.com



I just wired up an Automation Direct GS2 1hp 120 vac in, 220 vac 3 ph out. The GS2 definitely provides for resistor braking.


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## JimDawson (Jun 14, 2014)

uncle harry said:


> I just wired up an Automation Direct GS2 1hp 120 vac in, 220 vac 3 ph out. The GS2 definitely provides for resistor braking.




The GS1 series does not provide for a breaking resistor, the GS2 series does.  Also when needing to use 120V input, the GS1 series is limited to 1/2 HP.  The GS2 series has a 120V input, 1HP model.  I always purchase the GS2 units.  I have several.


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## ddmunroe (Jun 15, 2014)

*Re: Another VFD Question (looking for a supplier)*

Hi
Can anyone recommend a supplier for servo drive / controller package 2-3 hp.
Needs to run either on 220 or 415 ac power input. (220 1 phase 415 3 phase)
I don't think the hertz matters but in Australia the hertz is 50, service here is very slow
The internet search is the easy part, then after the phone call no one gets back to you.
Input appreciated
dd


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## JimDawson (Jun 15, 2014)

*Re: Another VFD Question (looking for a supplier)*



ddmunroe said:


> Hi
> Can anyone recommend a supplier for servo drive / controller package 2-3 hp.
> Needs to run either on 220 or 415 ac power input. (220 1 phase 415 3 phase)
> I don't think the hertz matters but in Australia the hertz is 50, service here is very slow
> ...




dd, I sent you a PM


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