I have taken the plunge and bought a great old shaper with 5-hp motor and a 2-hp feeder, both 3-phase. My basement of course only has single phase power. A person I know has a static phase converter that can handle up to 15 hp and is willing to sell it for $500 (app. 20% of what he paid).
Some of what I have seen written says that the static converters can only provide 67% of the motor horse power and I am also concerned that this unit might be actually too big for my shaper. The price seems reasonable, and hopefully I could run more future machines and as such I would like to have extra capacity for the future.
Does anyone have any input on the above?
Would appreciate anything you can add.
Replies
A static has to be sized for the machine. I wouldn't get his. You should look up the brand and contact the techs at the factory for the proper info.
A rotary would be a better option to run a variety of different sized machines. You could hook up a slave motor to make a roatry from the static but it doesn't make any sense to run a 15 hp slave motor to run a 5 hp shaper.
I would put a VFD on it. Gives you variable speed and more for less money.
http://www.factorymation.com/s.nl/it.A/id.208/.f
Rick's advice is spot on. I have a few 3 phase machines, and operate them with a rotary phase converter. I'm not a fan of static converters. With a rotary converter, a larger hp motor allows you to run several of your machines, and doesn't change from machine to machine like a static converter would.
I built my own, but there are several manufacturer's out there, and check ebay. They're listed there all the time.
Jeff
Sorry, missed the feeder part of the question. BAsic info still the same. Rotary will run both units. A seperate VFD on the feeder would be required to go VFD on the shaper. The plus again is more speed ranges but both VFD could be bought for around $500.
You need to study the info at places like Kay Industries, Phase-a-matic and many of the phase converter people. You need to talk to the folks at factorymation on VFD's to get the take on that.
Static converters can be fine as long as you know the limitations of them and the application.
The fourth way to convert is http://www.phaseperfect.com which is a total digital converter. The VFD will give you more bells and whistles overall.
The fifth way is to change over the motors. Sometimes it's an option but with many machines the motor is cast into the frame so it makes more sense to use a converter. Also you can't find single pahse motors over 7.5 hp so you need a converter. Do the research with the techs at the companies. There is more bad info than good info on the forums. Well intentioned but it should never be the last word to follow.
Thanks for the input.The unit my friend is selling is a ronk electric system. Im not even sure that its a static unit. Their site talks about inverters , but i havent been able to talk to anyone there so im not sure what it is.Am I correct in thinking that the VFD for $320 from factorymation will
do this? That certainly seems like a very reasonable price and simple solution.The shaper is wired for 3 phase, and the feeder is wired to the shaper.
I probably dont need any variable feed capabilities for this hookup as the feeder has that built in.
I will definitely check with the sites above and get something soon.
I also have to decide where to place the shaper so i have some time.thanks so much for all the input so far.stevo
You will need a seperate VFD for the shaper and feeder.
Having more options on speed with a VFD is a good thing. Consider it a bonus perk.
You maybe able to run the feeder off the motor of the shaper. Once the feeder is running the shaper motor would be considered a rotorary converter in itself, so you may be able to just use the VFD alone on the shaper and not have to buy one for the feeder. Again talk to the techs at the sources and take notes. It's a lot to learn in a short time and you are bound to get things mixed up.
I don't think electricity discussions belong on a wood forum.
You should have the Ronk model number and specs before you even start asking questions. I would have called Ronk with all the specs and asked what exactly is your buddy trying to sell you before I even asked on the forum.
This is how we did it before the net and I do not rely on the net for the answers. I rely on a tech from the manufacturer for real hard info.
Unfortunately the places that sell converters do not sell inverters so they won't be as much help. Have you talked to your local motor shop. Mine deals with converters and inverters so they are less biased to steer in one direction.
I called Ronk and asked about a shaper and converter vs VFD and he clearly only knew his product and said why would I want to have variable speed on a shaper motor. Bad answer in my opinion and experience. Variable speed on a shaper is a good thing and even if I have a step pulley on a shaper you can't get a rotary converter for the cost of a Factorymation VFD unless you build it yourself and are you ready for that? The bells and whistles such as infinitely varible speed and soft start are bonuses with a VFD.
HI Rick,
Thanks again for the input.
I realize that this is a wood forum. It was just my place to start.
I will talk to the factory people for all the vendors you mentioned and get the best solution i can find.Just one last question, if you dont mind. Please clear up one thing.Would i need both a rotary conv and a vfd? The posts go both ways.
It appears that the vfd you pointed me to has 3phase in and out. Other smaller hp models on their site have 1phase in, 3phase out.
Again, thanks for your help. I will definitely talk to the the vendors.
stevo
You wouldn't need both a rotary and a VFD. Actually you would need a higher rated VFD to work with you 5 hp motor. I talked with the tech at Factorynmation.
Start talking with different companies directly and take notes. If your local motor shop is on the ball they might be the best one to sort this all out. VFD companies and converter companies have their own agenda so if a rotary is better how are you going to know? Each application has it's own merits. Each type of machine has certain requirements. Pumps, CNC, saws are all different requiring different methods. I don't know all the details but have been setting up different 3 phase machines over 25 years and have had to sort through all the info.
"I know has a static phase converter that can handle up to 15 hp and is willing to sell it for $500 (app. 20% of what he paid)."
Looking at your original post I think you mean a rotary converter. Comparing Phase-a-matics cost wise the 15 hp rotary is discounted to $2100 in Enco which probably lists around $2500 which what you said your friend paid for his. A heavy duty static from Phase-a-matic goes for around $650.
The name “Static Phase Converter” is a bit of a misnomer because most commercial units are not really converters at all; they are simply motor starters. Once the motor is started, the “starter” drops out and you are left single-phasing your 3-phase motor. It isn’t the loss of power that is the issue with this as much as it is the imbalance in the phases to the motor. This is not healthy for the motor.A balanced static converter (not commercially common, but you can make one) is actually a converter and not just a starter, and it will provide nearly as much power (and balance) to the motor as a rotary converter. The down side is that you still need a separate converter for each motor. Normally for running two motors, a rotary converter is the cheapest alternative, but in your case, a properly configured VFD will work too. However, you need to understand that there is a lot of complexity in doing this. VFD’s do not like to be separated from their motors by a power switch or a reversing switch (at least not without some safeguards to protect the VFD). You need to have the VFD wired directly to the shaper’s motor, and then have the power feeder leaching power off of this circuit. This means that you cannot run the feeder unless the shaper is running. It also means that applying speed control (and more importantly, reverse control) to the shaper motor will also apply the same speed/direction change to the power feeder.Another consideration is that a VFD may not like seeing a sudden change in load when you flip the switch for the power feeder. An intelligent VFD is going to want to try to maintain speed and power to a motor, and when you flip the switch for the feeder, the VFD may react poorly, or kick out an error code and shut down the whole thing. A basic inverter that doesn’t have much intelligence may handle this fine, but most are microprocessor controlled.Although this was mentioned, it wasn’t really explained, but for a VFD above 2 to 3 hp, they will be expecting 3-phase input to power the VFD itself. The reason for this is because the VFD rectifies the incoming power and converts it into DC power (like a battery). It is more efficient to rectify 3-phase power than it is to rectify single-phase power. 3-phase power can be rectified into “smooth DC” power with nothing more that diodes, but rectifying single-phase power requires diodes, plus large filtering capacitors to remove the ripple.So when you feed a larger VFD with single-phase power, you need to oversize the VFD to account for the reduction in incoming power, but also to help the VFD handle the more noisy DC power than it would otherwise be expecting.
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