Another ph converter question

[LesWard]

I have a sliding table saw with an Italian 5Hp motor and was wondering if there is a VFD capable of converting 220V 1ph to 220 3ph at 5 hp?
And maybe a 3 to 5 hp metal lathe in the future.
Thanks

Les

[rrnut-2]

Yes, there is, Polyspede.com for one.
Other than the loud cooling fans, it works great on my 5hp lathe.

Jim B

[Les_S]

Hi Les,
You have phase converter in the subject line and VFD in the text so I'm not sure which one you are really after.
I just completed a Hitachi VFD conversion on my lathe and like it very much.
The Hitachi VFD number for your 220v single phase to 220 three phase 5 HP application would be WJ200-0075F I beleive.
I'm sure there are other brands of VFDs that will work equally as well, I'm just a Hitachi fan.
hope this helps,

The other Les

[Bentworker]

AC Tech SF250Y

[atomarc]

Les,

I have several machines running off of frequency drives and they all work well. I also have a Delta Unisaw with a 5HP, three phase motor running off a Anderson static converter. It also runs perfectly..no noticeable loss of HP, as a 5 hp for a home shop is quite a bit of oink.

I sure wouldn't rule out a static converter for your saw..this is a perfect application for one as you don't need the features inherent in a VFD. Compare prices..eBay has tons of static converters and Anderson has a real person you can talk to...Mr. Anderson. Take a look...looking is still free.

Stuart

[BadDog]

Not sure I would put a static on a big table saw. It likely has a larger blade to match, and it's actually at 5hp where table saws really get capable of handling real work. Then again I have a 7.5 hp lathe that I tend to push pretty hard at times. And I find myself feathering the in-feed my 2 hp saw FAR too often for my liking. For me, other options are too close to the same price to make that compromise acceptable. If nothing else, use the static as a starter to get a 7.5 or 10 hp idler going, and you've got a pretty decent (though unbalanced, which I could probably live with) RPC. Add a few run capacitors based on simple math and you pretty rapidly get to the point of diminishing returns where more balancing effort yields only slight improvements. An RPC would probably be my choice. And to put my money where my mouth is, I've built and used 2 that I was happy with, now using my 3rd which happens to be commercially built (30 hp fully balanced and CNC rated) and came to me with my new shop.

But if you can find a 5hp rated (at 1ph input) for an acceptable price, I don't think I would rule it out. Traditionally you don't have or really need speed control on a table saw cutting wood. But I expect that it might be nice to have some speed control when dealing with hardwood vs softwood. You sure do benefit from speed control when sanding. Problem is that from what I've seen VFDs jump dramatically in price (and size) above 2hp. When I was pricing VFDs for 5 and 7.5 hp machines, I quickly moved onto other options when I saw the price.

[scmods]

Les,

Google "Ferraris-Arno" and you will get to the roots of most rotary phase converters. The one I found was all in Italian, but the electrical schematics were all in standard symbolism and easily understood.

The unit I made from these diagrams has served me well for a number of years. It utilizes two close-coupled motors and three contactors. The 1/2 hp motor starts the rotation and has both windings connected in parallel. The centrifugal switch controls the start contactor, and when it drops out, it energizes the three pole system contactor which sends power to the 5 hp motor that does the converting and closes the load circuit to the machines, so when the unit is off, the entire load circuit is dead. The remaining contactor is a pilot for the unit that allows multiple remote start/stop capability, and allows the placement of the converter where the noise will be minimal, but you don't have to keep running all over to turn it on and off.

From operational experience, try to isolate the converter from the structure of the building so it doesn't amplify the sound. Perhaps rubber isolators like on a gas generator and a pre-cast concrete slab would be appropriate. An enclosure would be nice, but ventilation is a real consideration and would probably negate it's value.

Anybody for a retro-reflective sound isolation tunnel for an enclosure?

Bill Walck