Rotary Phase converters

[Junk]

Anyone ever build one of these? I'm picking up some 3ph equipment for the garage and need a converter. Been hearing about guys using rope to start the 3ph motor, using other smaller 110 motors to get it going etc. Anyone have any good info or good urls to recommend on reading up on building one? As usual, I don't have a clue what I'm doing, but am going to try anyway.

Thanks

[Mike S]

[quote author=Junk link=board=14;threadid=12785;start=msg117624#msg11 7624 date=1078805329]
As usual, I don't have a clue what I'm doing, but am going to try anyway.

[/quote]

That's the spirit, Ignorance is bliss!!

As for the answer to your question I have NO idea.

[Rich]

Search the archives of rec.crafts.metalworking. Everything to know and not know about phase converters has been posted there.

[Scamper]

Never heard of anyone building one, but you can buy 'em. Pretty spendy for a 3hp motor though; might be cheaper to get 3-phase delivered to your door (so to speak). Can't you just run a 3hp single phase motor? Or is this like a CNC machine you want to run?

[Vortec62]

I poked around and found this...

http://www.metalwebnews.com/howto/ph...converter.html

Here's another one from the same place:
http://www.metalwebnews.com/howto/ph-conv/ph-conv.html

[Vortec62]

Here's a bonus link for Junk that has some electrolytic rust removal info in it:

http://www.metalwebnews.com/howto/rust/rust.html

[TOZOVR]

[quote author=Junk link=board=14;threadid=12785;start=msg117624#msg11 7624 date=1078805329]
Anyone ever build one of these? I'm picking up some 3ph equipment for the garage and need a converter. Been hearing about guys using rope to start the 3ph motor, using other smaller 110 motors to get it going etc. Anyone have any good info or good urls to recommend on reading up on building one? As usual, I don't have a clue what I'm doing, but am going to try anyway.

Thanks
[/quote]

junk,

I'll talk to Will...he built his own, it's slick.


To quote a buddy,
"a three phase motor will not start on a single phase input but it will run on a single phase input. In such condition two of the three phases are not excited so that they can be used to generate phased current. Take those two generated phases and reintorduce the original single phase current and you now have three phase current that you can run a three phase motor with providing that the machine you want to run draws no more than you are putting out which is roughly related to the horsepower of the generating motor versus the horsepower of the using motor. Obviously, the load you put on the using motor is also important."

[Junk]

Thanks guys, appreciate the help.

[Poser]

I have a 5HP phase converter that I purchased new when I picked up the South Bend a few years back. Has wprked great, and I don't think I spent 150.00 on it.

My new Ellis drill press uses a three phase motor, but there is a electrical control box for the unit, that makes the three phase, not using an additional rotating motor like my 5HP unit, it is all IC stuff from what I was told..

Good luck!

-Steve

[Landpimp]

My folks couldn't get 3 phase at there place so they have a converter, its was bloody spendy and looks like something from the ages ago........its needed to run the elevator.

[Junk]

So far, Pimp and Poser have the coolest of toys. Got to love it. Poser, you got to post a pic of your shop or email some pics at some point. massive drool factor.

[Vortec62]

massive drool factor.

That's just a neurological disorder


Damn rookies always mouthing off

[Niner]

Just about any industrial motor distributor should have a VFD (Variable Frequency Drive) you can purchase them that will take 220 single phase and convert it to 3 phase 230 or 460 depending on the model purchased. these are very inexpensive compared to motor replacement at least for the company I work for, but you might want to check both options.

I have done this for some of our customers to allow them to purchase our standard equipment without having 3 phase in their buildings

[Poser]

Mike,

Niner nailed it, I could not remember the name of that piece attached to the new Ellis drill press, and that is it!!! VFD.

http://ellissaw.com/drillpress/9400.html

Good luck!

-Steve

[Junk]

Thanks. Yeah, saw some VFD's on ebay and such, just heard that they were not good for quick reverse - so some things would be tough. Seems to be the bees knees though for some things like step pulley machines etc.

Thanks for all the info.

[Poser]

Ellis tells me that I can reverse my drill press at any speed..for what that is worth...

[Junk]

Well yeah, but that drill is the shit. If you come home some day and see an 80 series high tailing it, with a out the window and NJ plates, ya better not look for that thing Just kidding, but that is an awesome drill press.

[Kief]

VFD's for most applications will allow a 3 phase motor to operate at it's true capacity as well. Rotary converters do not excite the windings the same as true 3 phase. A VFD takes single phase AC, turns it into dc and then back to AC, but 3 phase. No, I don't have any in my garage or at the shop.. sorry. VFD's also give you more speed control. Info from a fellow electrician that knows way more than me.

[Poser]

Kief,

I was told the same thing from an electrician guy that was out to the shop, a few weeks back...

[Junk]

Thanks Kief. Yeah, seems like those VFD's are the ticket pretty much. From what I can gather, it seems like there is a 50% limit, but not sure if that's in both directions or one. For example, if you have something set at 2,000 RPM and turn down the VFD, you could get to 1,000 RPM, or if you turned it up (assuming the machine and motor were capable) you could get 3,000 RPM.

Does that make sense?

Thanks!

[Niner]

As Kief stated VFD's do change AC in to DC but the DC is Made into a DC square wave Similiar to an AC Sine wave. The Motor sees it as an AC signal though. For a little more information The only Way to change the speed of an AC motor is to change the Hertz (HZ) In the USA our power comes to us at 60 HZ in other Countries it is 50 HZ. Hertz is how frequently the AC is switched from positive to negative thus creating the Sine Wave. Thus the VFD was developed to change the hz of electricity to change the speed of an AC motor. Until recently that is what these were used for, but for a small amount of money manufacturers were able to offer a unit that would accept an single phase input to 3 phase output. I hope this gives some what of an explatation of how they work.

Also not all VFD's will accept a single phase input so if looking for one get the correct model.

[Klunky Chris]

OK... Maybe I'm outta my league, but what exactly are you guys talking about ???

My gut tells me that 3 phase is refering to 220v/240v like is used for a dryer/stove/etc.
if so... then why don't you jsut run a 220v breaker and line to your garage?

or is that 2 phase?

If it is only 2 phase, then you are talking about a different service feed from the electric company? uses 4 wires maybe???

confused.....

(I'm currently learning about AC wiring... know plenty about 12v, but have been afraid of the hi-voltage stuff )

[Junk]

Niner, thanks for the info.

LOL Klunky, you just gotta focus on one wire, the one that's on your winch. Sent ya email on that synth rope that's been in my truck for 2 weeks now. Check yer email dude. 3 phase is the industrial type power - most older machinery runs on it but it cost a fortune to get it run to your shack assuming it's available. Cheaper to get a converter or VFD.

[Photoman]

Klunky,
Normal US house current comes in as two 110 lines and one neutral. 3 phase is basically 3 110 lines and a neutral. That's why 3 phase is not available everywhere. 3 phase equipment is cheaper to operate (start), next is 220, then 110.

Bill