Re: My first attempt in 3phase with a VFD

Thanks Wade.
I do not exactly know what a variac is, but
I appreciate the advice on hooking it up for a few hours before I hook it up
to the motor.

I have a photo of the tag, and a small pdf of the Vfd manual that I pulled
off the Internet.
I will Post it in my Lathe project Post in
Alt. binaries.pictures.woodworking if you want to see it.

I really appreciate the advice.

Rick
"Wade" <wmesquite@xxxxxx> wrote in message
news:1133594997.462936.263510@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> Rick,
> I've seen some good info and some misinformation in the thread. I don't
> know the Toshiba model numbers well enough to know if this is native
> single phase or not. I think I have a VFS7 manual pdf at work. If it is
> it will say it on a tag on the side of the drive and list something
> like input 8A 1 phase. If it only lists 3 phase on the tag, you probly
> have to derate it. If it has a 1 phase rating, the manual will state it
> somewhere. (If you can find the toshiba drives website (tic something,
> but a bit hard to track down, look for legacy drive), they have
> downloads you can search for the word single.
>
> If you have to derate, you get about 60% of the 4.0 Amps, or 2.4A
> continuous. It will start your motor by itself, probably start the
> motor and Reeves drive, and may even power the lathe for continuous
> moderate cuts. It will put out 2.4 X 150% =3.6A for a minute at a time,
> which will cover the full 1hp for any 1hp 1750 rpm motor I've seen. A
> bit wimpy for you lathe, but probly passable. If you don't have to
> derate, its fine. I don't remember any Toshiba's having undefeatable
> input phase loss detection, though they might. If a drive does have
> phase loss detection, and you can't defeat it, then it will not run on
> single phase. Often manuals don't say whether you can run single phase,
> but you can anyways.
>
> Toshiba is one of the few manufacturers to include recommendations to
> overspeed your motor; in an earlier VFD manual (VFSX) they mention for
> a 1750 motor it is okay to double the speed. 80hz is conservative. If
> your motor is a standard frame (56 or 143T/145T), then its easy to
> replace, abuse it as you like, a 3 phase replacement is not too pricy.
> The comment about the lathe not liking doubling the Reeves high speed
> is accurate, but if you don't exceed the lathe's top speed you're okay
> at 80, 90, or 100, or even 120 hz, though 80 is "safest". To access
> anything over 60, you probably need the remote pot.
>
> If it was made in 1997, then it may have sat around for a while, and
> the capacitors need reforming. The best way is with a 240 volt Variac.
> slowly ramp up the voltage, then keep it at 240V for 3-4 hours before
> hooking a motor to it. Equal is 120 variac + transformer. I think
> Variac w/o transformer to 120V,hold a bit, then switch to 240V is next
> best. Simply plugging it in for 4 hours at 240V will still do plenty
> good. If you don't do this, and it has sat around, it may die quickly
> on you. This might be in your manual.
>
> Its only a 1 hp drive, don't worry about the circuit and inrush. The
> basic idea is to cover the listed input single phase amps + a safety
> factor. But still an easier load on the circuit breaker than a motor
> with the same amps, where you have to oversize by more. It will stop
> your lathe pretty quickly, I'd try 3-4 seconds min or you start losing
> faceplates. You can add a braking resistor if you want LOTS of quick
> stops close together. Some you have to add a module for, $$$, justa
> resistor, then not bad, though you gotta house it. If you frequently
> overheat the drive into a trip from breaking, then get a resistor.
>
> Wade
>
> Rick Cox wrote:
>> Frank,
>> Would the "Inrush" be listed in a typical Manual.
>> The VFD I have is a Toshiba model vfs7s 2007up. It was manufactured in
>> '97.
>> It is rated at 4.0 amps at 1.6kva 0.5-80hz.
>>
>> Thanks for the heads up.
>>
>>
>> "Frank Ketchum" <fketchum@xxxxxxxxxxxxxxxxxxx> wrote in message
>> news:8XLjf.11416$aA2.206@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>> >
>> > "butch burton" <spacetrax@xxxxxxxxx> wrote in message
>> > news:1133478534.292758.283820@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>> >> If you use a VFD to convert 220 to 3 phase, will the motor it is
>> >> powering loose any power or is a 10 HP 3 phase motor powered with a
>> >> VFD
>> >> still 10 HP.
>> >>
>> >> Thanks
>> >>
>> >
>> > It won't loose power, but you still need a circuit capable of powering
>> > a
>> > 10hp motor to power a 10hp drive. Hope that makes sense.
>> >
>


.

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