single phase to 3 phase

[cedarsawdust]

I have a 2006 PRT alpha with a 5 hp colombo spindle hooked up to a
delta VFD-B . Its all set to go but needs 3phase power . I was hoping to
not change out the VFD and pehaps buy a rotary phase converter rated at 10 hp and cnc balanced +- 5v . anybody have some insight on phase con verters for me? Will they work , if so ,any brand suggestings ?

thanks for any input tony

[bleeth]

You might check out buying a 10HP VFD instead. That's the way you run a 5hp Columbo on single phase. You may find yourself ahead of the game financially although I have not compared them. Here's one on e-bay:
http://cgi.ebay.com/Delta-VFD075B43A...item2a025262c0
You can also post for a proposed trade on the "for sale" part of the forum.

The swap is really quite easy to do.

[CNCARTWORKS]

I agree totally. Just buy a VFD for 10 hp motor. If you got the spindle from Precision Drive they can make it east to do. Then supply 220 single phase to the VFD and you are done.

[cedarsawdust]

thanks for the input
that vfd on ebay was 3 phase 460v
I was told that the spindle / VFD wiring and programing
had to be done at the factory, meaning unwire ever thing sending the spindle away and buy a second VFD with a cost of about $1500 and an unwanted used 3phase VFD-B left on my shelf.
thats get be back to a cnc rotary phase converter,plug and play
only 800 bucks for a 10hp
the question is will it work ?
anybody running a shopbot with a phase converter going into a VFD?
seems like the least $$ and the least wiring hassles
no disassemble and shipping to factory then reinstalling =

thanks again tony

[cnc_works]

OK, Tony, just from my own experience...ymmv.

I bought a 3hp, 3ph spindle. Bought an unrelated 7hp 3ph VFD. I now run it all on 220, single phase. VFD can accept either 220 1ph or 220 3ph with no changes except how the power wires are connected and output 3phase to the spindle. No factory modifications necessary for my setup and I haven't experienced any downsides to it to date. And I'm also doing the same on my smaller CNC with a 1hp 3ph spindle and a different VFD.

That being said, I know of machinists who run a shop full of CNC equipment with 30hp or so phase converters...no problem.

Good luck!

[bleeth]

As Donn says, wiring it up is not a big deal at all. Those guys on e-bay sell the full line of Deltas, as Precision Drive does. I would contact them direct for the 230v you need. They look to be a couple hundred less than Precision. If you bought one new from precision I know they would send it to you ready to go. I did the wiring on mine as the first unit that came with my SB (those many years ago!!) was the wrong one. They sent me the right one right away and then I wired it myself with their instructions.

I just can't see adding another motor to the unit to avoid buying the VFD you need.

It is, of course, up to you. If you insist American Rotary has a pretty good unit.

[richards]

You might check www.automation4less.com for a VFD. They have a Hitachi X200-075LFU, which is 10hp 240VAC for $575.54. Check with them to see if that model can be used with 1-phase power when driving a 5hp spindle.

[cedarsawdust]

I now have the 10 hp delta VFD ready to go
My question now is :
the 5 hp Colombo draws about 15 amps on three phase
and close to 34 amps when run with single phase
do I now need to up size the jumper wires inside the control box
that go through the main switch and then over to the VFD
I ran 8 gage service cord, rated for 50 amps into the box only to find the other side of the main switch in the control box has only small thin wire maybe 12 gage at best.

any one know if I have to mess with [upgrade]the factory wires in the control box,in order to switch over from 3 phase to single phase ?

thanks for talking me out of the phase converter and into the more
economical 10 hp VFD but now I need a little more advice

Tony Davis

[bleeth]

I don't think so but I'll take a look at mine tomorrow and if it has larger jumper wires I'll let you know. Mine came prewired to the spindle by Precision Drive and has been running faultlessly for 6-7 years.

[dana_swift]

Tony, I am curious. In your original post you mention a "cnc balanced +- 5v". What is that all about?

My background is electrical engineering, and the term "cnc ballanced" is something I have never heard of before. Dual output power supplies are readily available in two forms "independent" and "tracking".

What needs the +/- 5? How many amps/watts?

The 5v requirement is independent of the 3phase issue. (according to me.)

D