Single Phase Conversion for Edgebander...

[Bradley Gray]

An RPC doesn't have to be complicated. The least complicated ones use a small single phase motor to spin up the idler. I have built a few this way. I mounted the starter motor on a hinged board with a handle to tighten-release the v-belt. 220v single phase to 2 leads, 3rd leg of 3 phase comes out the 3rd motor lead.

I think some companies that sell static converters also sell a control box for a rotary converter.

Used 3 phase motors can be had for very little $.

Likely once you have the converter you will find other used machines to add (I'm up to 18).

[Richard Coers]

I'd suggest some extreme caution here Bill. You are getting a ton of advice from people who have no idea what this machine is and the electrical components in the machine. If I found the correct machine, there is a control screen, limit switches, heaters, motors and more. A DIY rotary phase convertor does not put out clean power. There can be a pretty big imbalance and still run a motor. Not so much with transformers and control components. Same goes for a VFD. Don't buy the machine without have a machine electrical tech study the schematic and give you a knowledgeable answer. It's going to take a clean 3phase input.

[Charles Lent]

I agree with Richard.

There is more involved than just creating 3 phase to run a motor. Get a competent electrical tech or engineer to study the electrical drawings for this edgebander before you attempt to try to run it on single phase. If only the motor is three phase it would be quite easy to add a VFD to control it, but 3 phase heating equipment won't convert easily to single phase, nor will it run well from a home built RPC. Then you have the control circuits to deal with, but this will be the comparatively easy part.

Charley

[Erik Loza]

No dog in this fight but I just priced out a new Kay Industries phase converter for a customer in a similar situation. It was around $1K excluding taxes and shipping. To my mind, if this is your business, there's value in just being able to write a single check, have a new and totally functional unit delivered, then get to making cabinets rather than taking on a new fabrication project that may or may not work out. Just my 2-cents and good luck to the OP.

Erik

[Bill Kugler]

Would a commercially produced RPC generate clean enough 3 phase input?

Basically, there are two options available to me at the moment locally. There is a natively single phase Virutex eb135, and the eb140 plc. The eb140 plc is a much better deal, and a more feature-rich machine. But I am trying to figure out if it would still be a better deal after converting from 3-phase to 1-phase.
If a 3 hp RPC is required, and would work dependably, (according to the Virutex website, the eb140 is a 2.77 hp machine), then the eb140 still makes more sense.

If not, I may have to let it go.

[David Kumm]

Talk to the RPC people about the specific machine and the amperage. RPCs can be made to produce balanced volts at a specific amperage. They cost a little more but it is doable. A Phase Perfect will provide balanced voltage at all loads but I'm assuming you don't want to spend 4K for just one application. Three phase opens up a whole new world in machinery though. Dave

[Dan Friedrichs]

I'd suggest some extreme caution here Bill. You are getting a ton of advice from people who have no idea what this machine is and the electrical components in the machine. If I found the correct machine, there is a control screen, limit switches, heaters, motors and more. A DIY rotary phase convertor does not put out clean power. There can be a pretty big imbalance and still run a motor. Not so much with transformers and control components. Same goes for a VFD. Don't buy the machine without have a machine electrical tech study the schematic and give you a knowledgeable answer. It's going to take a clean 3phase input.

+1. Wise advice.

Rod Sheridan is right that the only component in the machine that runs on 3-phase is the motor - the other parts are single phase. But the complexity of how all those various parts hook to each other and interact could be a challenge.

You have several options:
1) Buy an RPC. You'd be "making" your own 3-phase power, and you'd power the machine with that. This could probably be done for hundreds of dollars. As Richard said, there's some risk a finicky control circuit or something gets upset by a non-ideal source of power.
2) Buy a Phase Perfect, which is a piece of electronics which creates 3-phase power using power electronics (rather than the machines used in an RPC). This is expensive.
3) Buy a VFD. You'd likely have to hook the motor directly to the VFD and control it using this. How does that affect other controls in the machine? Seems like a major surgery to the machine's electronics.

And one option no one has suggested, yet:
4) Swap the 3-phase motor with a single-phase one.

[Darcy Warner]

If a guy was smart enough, that would be easy enough to separate the single/3phase and actually wire control output to the vfd. I am certain that would be easy enough to program.

[David Buchhauser]

They do make big VFD's but above 3-5 Horsepower the cost skyrockets from 150 to the sky is the limit.
Bill D.

10 HP VFD - $172.00 with free shipping. As I previously stated, I have been using the 5 HP version for several years with no complaints.
If the piece of equipment in question has input terminals for the three 3 phase power, and all the other single phase accessories are wired internally (as I would expect - since all of my large cnc machining centers separate the 3 phase and single phase components internally) - then the only wiring to be done is to connect the three output wires of the VFD (plus ground wire) to the three input terminals (plus ground terminal) of the equipment. Since this application is for phase conversion only and not speed control, the VFD programming for ramp up, ramp down, torque control, decelerating stop, coasting stop, DC braking, etc. would not necessarily apply. This should be a pretty straight forward installation. It would also be nice to see the installation manual, wiring diagrams, and other specs for the piece of equipment in question. This could help make a more informed decision.


David Buchhauser
(Electrical Engineer)

https://www.ebay.com/itm/7-5KW-10HP-....c100005.m1851

[Mike King]

Talk with Jack Forsberg. He can tell you whether the vfd will work, how much it would cost, and how to rig it up. He’s supplied a lot of vfd’s to people on this site.

mike

[Dan Friedrichs]

10 HP VFD - $172.00 with free shipping. As I previously stated, I have been using the 5 HP version for several years with no complaints.
If the piece of equipment in question has input terminals for the three 3 phase power, and all the other single phase accessories are wired internally (as I would expect - since all of my large cnc machining centers separate the 3 phase and single phase components internally) - then the only wiring to be done is to connect the three output wires of the VFD (plus ground wire) to the three input terminals (plus ground terminal) of the equipment. Since this application is for phase conversion only and not speed control, the VFD programming for ramp up, ramp down, torque control, decelerating stop, coasting stop, DC braking, etc. would not necessarily apply. This should be a pretty straight forward installation. It would also be nice to see the installation manual, wiring diagrams, and other specs for the piece of equipment in question. This could help make a more informed decision.


David Buchhauser
(Electrical Engineer)

https://www.ebay.com/itm/7-5KW-10HP-....c100005.m1851

David, what if the machine has limit switches which control the motor?

[David L Morse]

David, what if the machine has limit switches which control the motor?

Actually, the motors (there are three) could each have their own VFD internally. I suspect that control is fairly complex on this machine and could involve more than simple on/off control of the motors.

[David Buchhauser]

David, what if the machine has limit switches which control the motor?

Hi Dan,
Basically the limit switches won't know the difference whether the power source for the machine is 3 phase from the power company, 3 phase from a rotary phase converter, or 3 phase from a VFD. Many of these machines utilize internal DC power supplies (derived from AC) to supply DC voltages to various internal components within the machine.
David

[David Buchhauser]

Would a commercially produced RPC generate clean enough 3 phase input?

Basically, there are two options available to me at the moment locally. There is a natively single phase Virutex eb135, and the eb140 plc. The eb140 plc is a much better deal, and a more feature-rich machine. But I am trying to figure out if it would still be a better deal after converting from 3-phase to 1-phase.
If a 3 hp RPC is required, and would work dependably, (according to the Virutex website, the eb140 is a 2.77 hp machine), then the eb140 still makes more sense.

If not, I may have to let it go.

Hi Bill,
If funds allow, I would recommend going with the RPC. I would recommend American Rotary. I purchased one of their larger cnc rotary phase converters (30 hp) over 15 years ago to run the 3 phase equipment in my shop. This includes 15 hp spindle motor on my larger machining center, 7 1/2 hp spindle motor on the smaller machine, 7 1/2 hp spindle motor on cnc lathe, and several other 5 hp motors on mill and conventional lathe. I sometimes have 3 or 4 machines running at the same time. This American Rotary phase converter is still running fine, have never had a problem with it - very reliable.

20190813_193522.jpg20190813_193528.jpg20190813_193556.jpg20190813_193609.jpg

Here is the American Rotary 5 HP phase converter (below). Made in USA. $439 with free shipping.

David

https://www.ebay.com/itm/American-Ro...UAAOxybi9RcwrJ

American Rotary 5 hp phase converter.jpg

[Bill Kugler]

Thank you very much everyone for the helpful advice and replies.


Unfortunately, the edgebander sold (it was a good deal, I figured it would go quick). But I am noticing there's a definite lack of single phase options for quality edgebanders, so I'm guessing I may still need this advice in the coming weeks/months.