Vfd Motor question

[daveo]

So where is a good start to learn about vfd motors and controllers?

Instead of derailing my band saw thread, I figured Id start a new one.

I have the idea of building the band saw with a variable speed motor, also a old Atlas 618 lathe that could use the same treatment. Eliminating all those pulleys and brackets....

The problem is, all I know about motors is how to order the same one to replace it. I have searched here and other places but there is no good "starting" point to learn about them...

[KiddZimaHater]

I was in the same boat when the old motor on my lathe went up in smoke 2 years ago.
Everyone told me to get a 3 phase motor with a VFD.
I was utterly lost. I knew next to nothing about motors, voltage, 3 phase, amps, electronics, etc. ???
So I bought a 2 horsepower, 3 phase Baldor motor, and a VFD to power it.
Just make sure the VFD is rated to power the same horses as the motor.
I had an electrician come over and explain a few things to me, and help wire it so I wouldn't screw anything up.
And I learned a few things.
Don't be intimidated by the VFD, 3-phase thing.
It's really simple to set-up, wire, and get going.
From your 220v breaker, install an on/off safety switch.
This will power on/off the VFD (since there is no on/off on the VFD).
The fuses in the box will also help to protect your VFD.
Then, from the switch, run the 2 wires (220 Single phase) and ground wire into the VFD input.
From the VFD output, run the 3 wires (3 phase) and ground wire to your motor.
The motor will have a wiring diagram to show you how to connect the wiring.
That's it!
It's really simple.
Turn on the switch, and use your VFD manual to set the VFD's parameters.
Piece of cake...

[dian]

also make sure your motor is wired delta for 1 x 220v input, 3 x 220v output.
for 3 x 400 input and 3 x 400 out it has to be Y.
i understand, recently, there are 1 x 220 in, 3 x 400 units also, Y of course.

[MaxHeadRoom]

If you get a 4 pole motor, you should be able to run double the frequency, up to around 160Hz, with a 2 pole, you are taking some risk above 60Hz, (balance and bearings), this is if it is a non-vector rated motor.
If vector rated, the manufacturer will state max rpm.
Max.

[daveo]

I was in the same boat when the old motor on my lathe went up in smoke 2 years ago.
Everyone told me to get a 3 phase motor with a VFD.
I was utterly lost. I knew next to nothing about motors, voltage, 3 phase, amps, electronics, etc. ???
So I bought a 2 horsepower, 3 phase Baldor motor, and a VFD to power it.
Just make sure the VFD is rated to power the same horses as the motor.
I had an electrician come over and explain a few things to me, and help wire it so I wouldn't screw anything up.
And I learned a few things.
Don't be intimidated by the VFD, 3-phase thing.
It's really simple to set-up, wire, and get going.
From your 220v breaker, install an on/off safety switch.
This will power on/off the VFD (since there is no on/off on the VFD).
The fuses in the box will also help to protect your VFD.
Then, from the switch, run the 2 wires (220 Single phase) and ground wire into the VFD input.
From the VFD output, run the 3 wires (3 phase) and ground wire to your motor.
The motor will have a wiring diagram to show you how to connect the wiring.
That's it!
It's really simple.
Turn on the switch, and use your VFD manual to set the VFD's parameters.
Piece of cake...

So what if I dont have 3 phase, will I need a convertor?

[MotorradMike]

Make sure you get a VFD that will accept single phase input and it will make the 3 phase for you.

[Forrest Addy]

One more detail. You can turn down your VFD for light cuts that draw little HP but you steill need to shift belts and gears for actual stock removal. For any particular motor HP is proportional to RPM. You can quibble details and minor figures but that's about how it works.

An induction motor is a constant torque gizmo. Have the RPM and you halve the HP. Like this: 2HP @ 1750 RPM (60 Hz); 1HP @ 875 RPM (30 Hz), 1/2HP @ ~440 RPM (15 Hz); 1/4 HP @ 220 RPM (&.5 Hz) like that.

Install the VFD and thre phase motor. Arrange the new controsl to integrate to old ones. You will wonder why your didn't make the change long ago. BUT, for heavier cuts you will still need the mechanical reduction so don't throw away any parts.

[daveo]

for heavier cuts you will still need the mechanical reduction so don't throw away any parts.

Thanks for the help, I throw away no parts

[bmw625]

pay attention to Forrest -- I read his vfd tutorials, and powerd up a 3 phase drill press. It was so neat, I switched my lathe and mill to 3 phase motors w/VFD's they are fantastic !!
brent

[daveo]

pay attention to Forrest -- I read his vfd tutorials, and powerd up a 3 phase drill press. It was so neat, I switched my lathe and mill to 3 phase motors w/VFD's they are fantastic !!
brent

Point me in the direction of these tutorials you speak of

[bmw625]

Point me in the direction of these tutorials you speak of

here's a start :

http://www.practicalmachinist.com/vb/transformers-phase-converters-vfd/vfd-newbies-102866/

brent