# VFD off of RPC ? limitations



## PrestigeR&D (Jan 6, 2010)

*good,*

I was going to ask you about my flux capacitor :jester::laughing::laughing:.
So whats up John- Did you see Electrics post- ?


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## John Valdes (Apr 14, 2010)

Yes, I am still waiting.


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## John Valdes (Apr 14, 2010)

Maybe the moderators must manually set the software. I now have 17 post's.


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## PrestigeR&D (Jan 6, 2010)

*I have no clue whats going on,*

So what is the problem? 
Brian


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## Electric_Light (Nov 25, 2007)

PrestigeR&D said:


> I didn't realize there were different types ,With the back to back RPC - you say they produce steay 3ph which I would assume could run a VFD off of that then . I saw a 10hp RPC for $560.00. If this is the case and this will work I will go the RPC route- but as far as the specifications - what would I be looking for ie; back to back rpc as far as description?
> 
> This is what I came up with :
> General SpecificationsModelPPC-RPR-10HP-WPBHP10kW7.4Type RatingExtreme Duty, CNC / All-PurposeIdler Frame Required215TInput Voltage208-250 voltsOutput VoltageSame as Input Voltage +/- 5%IdlerTEFC (Total Enclosed Fan Cooled)1-Phase SpecificationsInput Voltage208-250Approx. Idle Amps1.23Frequency (Hz)60Efficiency>98%Minimum Breaker Size20Maximum Breaker Size50Min. Wire Breaker to Converter6
> ...


It's addressed here that MG-set type provides the most balanced phase output.
http://en.wikipedia.org/wiki/Rotary_phase_converter

This is what an ordinary idler type phase converter looks like. 

An idler type usually looks like this
http://www.phaseconverter.com/data_sheets/6515ss.pdf
In the spec, one phase is said to have +5% voltage, and this is the voltage that is excited with single phase. Under load, the variation can increase even more. An idler uses a single phase input and a starting mechanism to get a three phase motor running on single phase and create the other two phases using the same windings. 

An MG-set style is like a three phase gas generator, but with a single phase motor mechanically driving the generator in place of an engine.

An MG-set looks like the black one here:
http://www.electricpowergenerator.com/motor-generator-sets.html

It all comes down to the level of acceptable phase imbalance the VFD can put up with.


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## John Valdes (Apr 14, 2010)

I cannot do anything but type posts. I wanted to send you a link for a VFD that would work in your application. Then we could discuss. 
I can't find a moderator either. I am a member on the sister site. Seems I would have some privileges right away?


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## John Valdes (Apr 14, 2010)

I cannot even PM a moderator?


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## PrestigeR&D (Jan 6, 2010)

*Found the solution, going with a VFD.,,,,*

I called a friend of mine,distributor ,Anton, (VFD-Guroo) yesterday - explained that I need a VFD rated for 220v single ph as the input rated at 3hp and 13.5 amps to drive my Master Motor for the Moak 32" BS. 
He came up with a Yaskawa CIMR-PBAB3P7 with the optional JVOP-100 digital remote keypad. It is rated and designed for 220V single phase input and the output is 3ph, 5ph @ 17.5 amps. No RPC needed for 5hp after all, but after that the VFD's get quite expensive but I probably would still go that route none the less- in the long run. The RPC would constantly be running and drawing a lot more current continuously way more than the VFD. Not that I am against RPC- but I am looking at the overall costs with both. I would be paying more for my electric bill for that RPC , it would cost 1/2 of what the VFD would, but I make up for that and then some because the VFD is not constantly running- only when the machine gets turned on does it draw current and that is saving me money on my utility expense over the long haul. 

For those of you that understand this, here are the specs on the CIMR-PBAB3P7/JVOP-100 : http://www.yaskawa.com/site/dmdrive...$File/TOE-S606-1D VS-606 PB3 Instructions.pdf .
Brian


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## grayman74 (May 5, 2010)

*Automation Direct*

I started reading this thread this morning (I've been lurking on this board for some time now) and would highly suggest following Dean's recommendations - Automation Direct is a great company and they have a 30 day money back policy on most of their stuff. I've spent several hours on the phone with Dean recently on a servo application and I don't have enough kind words for him. Dean is the man!


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## PrestigeR&D (Jan 6, 2010)

*Gray,,,,,??*

I don't believe you read my new post,,,I found my VFD already-open the link- its all there,, I wanted a Yaskawa- it's all done:thumbsup:
Brian


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## grayman74 (May 5, 2010)

*Automation Direct*

Did you find that the drive from Automation Direct would or would not work? Just curious!


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## PrestigeR&D (Jan 6, 2010)

*Grayman,*

First of all what is your name?? I hate this handle identity, 

You can find out all the information here: http://www.contractortalk.com/f40/moak-32-band-saw-74641/index4/ 


I deal strictly with Anton
Brian


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## grayman74 (May 5, 2010)

*Automation Direct*

My name is Jeff, I'm new here - still trying to figure everything out.


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## John Valdes (Apr 14, 2010)

Glad to see you got it all straight. For some reason I thought this was a new thread as it is so old.
Yaskawa builds a great control. One of the best. They built for many in the past including Magnetek. Why you would need an extension for the HIM is not clear. 

One more thing I saw as I read this whole thread again. You mentioned running an RPC and VFD together. I have found in many instances that the RPC may have an output not suitable for the VFD. This is not a certain, but an observation. In any case a line reactor woulds solve any input concerns.

Good luck

Welcome Jeff


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## PrestigeR&D (Jan 6, 2010)

*John,*

thanks for the input,, yea,, no I am scrapping the RPC all together- and Yes, Yaskawa drives are very well engineered, little pricey out in the open market, luckily I have a friend that sells them to me at almost wholesale prices. But I am not going the RPC route-not cost efficient in the long run and no bells or whistles with that setup- and you are correct, RPC, and VFD's tricky situation, it can work but in many cases it is risky. 
Thanks:thumbsup:
Brian


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## PrestigeR&D (Jan 6, 2010)

*John,*



John Valdes said:


> Brian,
> I checked a supplier I used back when I ran a motor and drive company. KB Electronics. They specialize in small controls. AC and DC. They have chassis mount and complete units with speed pot and stop/start/forward/reverse ready to go out of the box.
> Check out this one. Look at the wiring diagram, specifically. With this one you just connect and go.
> 
> ...


I looked at the link and the specifications,,it will not work- The motor on the Moak BS is: -13.AMPS-3hp 575RPM, 220vlts/3ph , The KBAC-29 is the limit for (208/230) single phase Input and the Load amps for that unit are 6.7 @ 2hp max rating - thats it. The Yaskawa is (208/230)single phase input, and, 17.5 load amps load output ,rated at 5hp. 
Brian


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## John Valdes (Apr 14, 2010)

PrestigeR&D said:


> I looked at the link and the specifications,,it will not work- The motor on the Moak BS is: -13.AMPS-3hp 575RPM, 220vlts/3ph , The KBAC-29 is the limit for (208/230) single phase Input and the Load amps for that unit are 6.7 @ 2hp max rating - thats it. The Yaskawa is (208/230)single phase input, and, 17.5 load amps load output ,rated at 5hp.
> Brian


My intention was not to pick a drive for you. It was to show you some small AC inverters available that have not been around for all that long.
That is one special motor you got there! 575 RPM. Its must be an 8 pole motor rated at 50Hz?


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## PrestigeR&D (Jan 6, 2010)

*Yep,,*

I think it is 8 poles,, I still heave to order the VFD, when i get it, I'll update the VFD mount to the Moak,:thumbsup: 
Brian,


How can I tell? 
Brian


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## John Valdes (Apr 14, 2010)

Does your motor have inverter magnet wire? You might smoke that motor if its real old. If you do smoke it, just take it to a good motor shop and have them rewind it with 1500 volt coated magnet wire (spike resistant) and have them use insulated bearings. Tell them it will be on an inverter. If they are good they will know what to do.

It seems this motor is special. If not, it would be cheaper to replace it with a inverter duty motor. What is the frame size just in case. I have upgraded lathes before and used a standard frame with motor mount. Then you can either weld the motor mount or bolt it to the machine. Like I said, just in case?

Ps.....I just checked and you do have a special motor. Standard motors at 3HP come only in 6 pole (900 RPM). The drive would take care of the speed though.


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## PrestigeR&D (Jan 6, 2010)

*Hey John,,*

What so you mean ,, I might smoke it???? I really don't know all the technical data about the motor other than what is on the spec face plate. Why do you think I may smoke it? 
Thank you
Brian


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## CE1 (Dec 30, 2005)

PrestigeR&D said:


> What so you mean ,, I might smoke it???? I really don't know all the technical data about the motor other than what is on the spec face plate. Why do you think I may smoke it?
> Thank you
> Brian


Another John here.....

Yes you will burn up the motor, especially if you are going to use it a lot. Older motors will not tolerate the output of a VFD because they were not built to the specs of today's motors. 
I suggest that you take the motor to a motor repair shop and see if they can replace it with a single phase motor or as John V said. rewind it for VFD use. 
The RPC would still be your best bet. simple, easy and quick. :thumbsup:

Can you post a picture of the motor and mounting? You may be able to replace it with a single phase motor.

Carry On!


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## PrestigeR&D (Jan 6, 2010)

*John,,,,,ce1,*

I must say,,,,,, I am a little worried about my motor , However,, I will try and get more info on it. CE1,,,,I do NOT want single phase equipment- period. I don't know how familiar you are with commercial WW equipment but you would be hard pressed to find single phase drive motors on any of the equipment- they run more efficiently than single phase. 
Step over to OWWM some time,, you will see what I mean. 3 phase equipment is basically the rule over there. The worst case scenario with my motor is I will have it rewound as an inverter duty motor, but NOT single phase - that is not going to happen. 

As it stands now, you and John are the only ones to tell me that my motor is going to "toast up" -- can you please explain to me "why" -technically,,,,. 
I appreciate the input , seriously, but my makeup as a person is I personally need to understand "How things work" and why,,,

look forward to your response, and thank you,
Brian


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## CE1 (Dec 30, 2005)

PrestigeR&D said:


> I must say,,,,,, I am a little worried about my motor , However,, I will try and get more info on it. CE1,,,,I do NOT want single phase equipment- period. I don't know how familiar you are with commercial WW equipment but you would be hard pressed to find single phase drive motors on any of the equipment- they run more efficiently than single phase.
> Step over to OWWM some time,, you will see what I mean. 3 phase equipment is basically the rule over there. The worst case scenario with my motor is I will have it rewound as an inverter duty motor, but NOT single phase - that is not going to happen.
> 
> As it stands now, you and John are the only ones to tell me that my motor is going to "toast up" -- can you please explain to me "why" -technically,,,,.
> ...


Brian,

I didn't mean to say to rewind the motor for single phase, I meat to say replace it with a single phase motor. That is why I asked if you could post a picture of the motor and mounting.
I do understand the reason for 3 phase equipment, but you don't have 3 phase power. A new 5 HP single phase TEFC motor will run just fine and will produce the same amount of POWER as that of a 5HP 3 phase motor, so you would not see any difference using a single phase motor. The only reason for using 3 phase for industrial and commercial motors and equipment is that it's cheaper to install, as in wiring, controls, etc.

It all depends on the present motor's condition as to how long it will last using a VFD. It could be 5 mins or it could be 5 years. Another issue that you might want to keep in mind is that the existing motor will get hotter than normal using a VFD. Mix heat and wood and what do you get?:furious: Also heat will tend to break down the insulation on the motor. The more you use it, the more often you use and how hard you use it will determine how long before you get a motor failure.

John


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## PrestigeR&D (Jan 6, 2010)

*Thanks John,,,,*

So what information do you need- /pictures? I appreciate the helpful input:thumbsup:,, It is a 60hrtz , not 50. and this thing is absolutely huge- it has got to weight in at over 200lbs, beefy is an understatement. The motor cicumfrance is 42" and the diamiter is slightly over 13" 
Let me know if this is enough, and again ,, thank you John:thumbsup:
Brian


On a side note: I want to keep this motor, even if that means throwing more money into it,, whatever it takes- It is the original part of the BS and I do not want to replace it,,,, I think you can understand why ,,,OWWM ,, We try to keep the machines as original as possible.
Brian


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## CE1 (Dec 30, 2005)

Portable rotary phase converter.....

View attachment 32188


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## PrestigeR&D (Jan 6, 2010)

*John,,*

That is pretty slick:thumbsup:
So what would I be looking at-, and I understand that you have to over rate it - correct? 
Brian


John CE1,
Hey, thanks for the input and all , but I am going to stick with the VFD-talked with a motor rewinding engineer- BOB and/VFD tech Jason,, this morning,,,, they agreed-VFD, I do appreciate the input though- thank you.
Brian


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## John Valdes (Apr 14, 2010)

Brian,
Don't listen to the new John, get confused and we have to start all over again. You have already purchased the VFD. Right? You have spent hours with me and the VFD's technicians. Right? You KNOW the VFD will do the job for you at a fraction of the cost of a RPC. Right.

No Disrespect new John, but your have interfered with a problem "solved" and are making this much more difficult that it is.

Brian. All I want you to know is yes, a VFD can be hard on a motor that is not designed for VFD use. This is by no means a reason to abandon all of our work and trouble. Should the VFD smoke the old motor, you will need to have it rewound for inverter duty. Also, if this happens (we cannot guarantee it will) have them install insulated bearings. Not required, but a good investment. *This old motor may never give you one bit of trouble on the VFD. Or it could smoke the first day. No one knows!*
I am very surprised that any VFD knowledgeable technician would not have asked about the motor. That is the first thing they should have discussed with you. I am sorry I brought it up so late.

So, relax, forget about single phase motors (You will NEVER find one on that frame), forget about everything you have read on this forum in the last couple days and continue with your plan. It is a good plan and it is a proven plan that works. I have converted many lathes in my career. And yes, sometimes I have to rewind or buy a different motor. It comes with the territory.

Ask the VFD salesman how much a load reactor will cost and what the current is? Then tell me. This is a cheap power conditioner for the load side of the VFD. It will clean up the VFD output signal.

New John (CEI) Please read the complete post before you start giving advice. In this case you have done more harm than good. Read it all and you will see what you have done to a thread that was "RESOLVED". You also have caused Brian to worry and we don't need any more worry than we already have.


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## John Valdes (Apr 14, 2010)

Check your messages, Brian


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## PrestigeR&D (Jan 6, 2010)

*Hey John,,*

yea, I got them,, thanks- it's all good. just wanted to pick your "sparky storage device",,,"Brain":laughing::thumbup: for a minute- well talk later and thanks:thumbsup:
Brian


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## CE1 (Dec 30, 2005)

John Valdes said:


> Brian,
> Don't listen to the new John, get confused and we have to start all over again. You have already purchased the VFD. Right? You have spent hours with me and the VFD's technicians. Right? You KNOW the VFD will do the job for you at a fraction of the cost of a RPC. Right.
> 
> No Disrespect new John, but your have interfered with a problem "solved" and are making this much more difficult that it is.
> ...


I did read the whole thread and the thread about when Brian was in the process on buying the band saw.....but it appears that you have some kind of vested interest in this project.

So....continue. :notworthy


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## John Valdes (Apr 14, 2010)

No John, No interest monetarily. I just have been working with Brian for several weeks and he has been working with his own vendor. Just when he was on track you came into the picture and I kinda jumped on you some and did not mean to offend you. I talked to Brian on the phone yesterday and he is all set and is purchasing the VFD and load reactor. He is aware of possible motor failure, but he has received a quote to rewind his motor for inverter duty. We are hoping he does not have to rewind. Its not a given.

So, sorry about yesterday. But around here thick skin is a requirement and it looks like you don't have thick skin.
I Look forward to working with you on future posts and threads.......John


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## PrestigeR&D (Jan 6, 2010)

*UPDATE: my thoughts about this after reading a post...*

John...
I have done some research on this.. VDF vs RPC.. and my conclusion was that the RPC will work...is less expensive "initially" no doubt.. but what gets me about this it "it" would be running and I may have no machinery being run in the mean time and I have to pay the electric bill...another down side is I have no options.. soft start.. dynamic breaking.. etc..etc..etc... 
I belong to several forums.. other than WW ing..and one guy had a 30hp RPC ... thought it was a win.win. as far as bang for the buck....that was until he got his electric bill......it added another $268.00:w00t: to his electric bill in 1 month.. now to me that does not sound write but he swears by it.....I can't see why he would not be honest about this..and here's why...
He got rid of the RPC,:w00t: sold it and put the proceeds and some additional $$$ on VFD's for every machine 11 in total... and his bill for that month... an additional $82.00 :laughing::thumbup: and $2700 on vfd's but if you add up the added cost for the electric bill... in 1 year.. they paid for themselves...and then some..
What I have learned since I started getting involved with 3ph WW equipment 5 years ago is - not every application works for everyone depending on the AMP service /the HP rating on the machines themselves...there are limitations to VFD's and that is based on HP rating and $$$ . 


B.


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