Using static 3 phase converter to feed VFD

I am about to purchase a Mill/Drill (RF-31) that is setup with a 2 HP motor and a VFD. Unfortunately, this VFD has a 3 phase input and I do not have 3 phase at my home. I was planning to use a low cost static converter on my single phase 220 supply to feed this.

Are there any problems with having two converters like this? I am also considering a new VFD with 1 phase input, but the cost is $200 vs $50 on ebay.

I appreciate your input on this issue.

Larry

A static converter does absolutely nothing that will help you.

They are really just a way to start a 3 phase motor on single phase, and then run it on single phase also. There is no "conversion" involved.

The 3 phase unit MAY work on single phase, but probably at a reduced power capability. You can check the manual to see if that is allowed.

I suppose a rotary phase converter would supply 3 phase to a VFD, but for 2 HP it would want to be a considerably larger idler, probably a 5HP, due to the way the VFD draws power.

Sorry there is no magic bullet to solve this issue.

JST said:

A static converter does absolutely nothing that will help you.

They are really just a way to start a 3 phase motor on single phase, and then run it on single phase also. There is no "conversion" involved.

The 3 phase unit MAY work on single phase, but probably at a reduced power capability. You can check the manual to see if that is allowed.

I suppose a rotary phase converter would supply 3 phase to a VFD, but for 2 HP it would want to be a considerably larger idler, probably a 5HP, due to the way the VFD draws power.

Sorry there is no magic bullet to solve this issue.

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The real question is WTF are you buying a POS rong fu mill drill? For what that POS costs you could get a decent Bridgeport, have a mill you can actually do some work on and it will never be worth less than you paid if you got any sort of a deal on it at all. Think hard about this, machine work is no fun at all when you are using junk.

Thanks for the reply. Does this apply if I get a new VFD that supports single phase input? Do I still lose half the power in that case? I would guess that I get the power back through a higher frequency.

Larry

Wow...

Yeah, Larry- the original 3-phase drive just might operate on single phase as-is... but I'm certain that it'll be very low quality... enough such that it'd probably fail even when properly powered. Changing it for a single-phase drive... would result in another Chinese-made VFD... on a loose and clunky chassis and weak motor and belt situation.

Money-wiser-spent, would be for a used Bridgeport BRJ and an old Allen Bradley 1305 type AA12A, feeding 240v single-phase to A and C. Program it, and go cut metal... My BRJ cost me $500, and the 1305 cost me $50....

lr172 said:

I am about to purchase..
.
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I appreciate your input on this issue.

Click to expand...

Then just don't do that.

Let us ass u me that you figure your milling loads are "light enough" it would "do".

Modest loads on a milling machine may be the case. But a MMSO (Milling machine Shaped Object) can still overload your time, safety, maintenance, ruint work and tooling - IOW "F**k with" or FRUSTRATION budget.

A Bee Pee is only one better answer. There are scads of older "real" light/medium mills out there, US, Canadian, Taiwanese, Basque & other European. Some lighter, some heavier than a Bee Pee. Most are quite affordable. WTH horizontal mills can be near-as-dammit "free".

Essentially ALL can outperform a Wrong Fu, do better work with less hassle, last longer on smaller money going forward, even if rather badly worn the day they are rolled in your door.

I suppose, yes, you could use the static converter directly with the 3 phase motor.

It will not be very wonderful as to motor performance, but then the machine is not very wonderful.

That must be a retrofit, most of those mill0drill have single phase motors