Running my 3-phase bandsaw using a VFD

[mreza Salav]

I recently got a bandsaw that has a 3-phase (3HP) motor. I purchased a VFD (this one: http://www.factorymation.com/s.nl/it.A/id.198/.f?sc=2&category=32) to run it off single-phase 220V power. As it was suggested to me here by Erik to document how I get this run I have taken some photos that I post below.
The VFD comes with a little booklet which you can also download as a PDF online. I suggest to get the PDF version as the instruction booklet is way too small to read easily.
The most important point to remember is to have the output of the VFD directly connected to the motor (with no switch or disconnected in between).

First I decided to do a test run to see how things need to be wired. I don't have a blade yet (they are on the way).
The first photo shows the bandsaw in its original shape.I took the wires out of the motor and connected them directly
to T1,T2,T3 (which are output) of the VFD:

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The power in to VFD goes to L1 and L3 if it is single-phase (for the case that the input is 3-phase too then you use L1,L2,L3).
To control the unit I use the two multi-function inputs. In this case input 5 is a 12V power and 3,4 are for forward/reverse control of motor. If you connect 3 to 5 it will start the motor in forward case and with 4&5 you get reverse rotation. The factory setting was a 5HZ which you can adjust to 50Hz.

Since the multi-function input is low voltage I use a simple light switch to control it in the test run. I turn the saw on and check the amp usage:

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It is using only 2amp on input (with only the lower wheel rotating as there is no blade). At start-up it goes up to 10amp.
next post...

[mreza Salav]

Removed the main switch and emergency stop and sent the wire from the motor to the front (where the old switch was):

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Started building a housing for the VFD to be installed instead. Had some black (shiny) acrylic sheets. A thick metal plate will be placed on top to which the VFD will be screwed as a heat sink:

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[mreza Salav]

Here I'm installing the VFD and a switch and a partial housing to cover the end of wires:

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And these last few pics show it finally done:

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Didn't want to drill any holes into the saw, so I'm using the original holes (for the switch mount) to mount this.
The good thing about VFD is that you can control how quickly it stops the motor (kind of a break). The saw has a foot brake but I guess I won't use it with the motor break.

Here is a short video of running the saw (sorry for the mess on the table, didn't clean it up before taking the video).
http://www.youtube.com/watch?v=_0BT8nUALaQ

[Bruce Page]

Very clean installation Mreza. I love the fast breaking, it will be slower with the mass of the upper wheel & band but still much nicer than using the foot break.

[Carl Beckett]

Very nice install Mreza, thanks for sharing.

$175 for the VFD opens up a lot more purchasing decisions when shopping for tools (especially used ones).

[mreza Salav]

Thanks. I hope it helps others who want to go this route but are scared of complications. It wasn't bad at all. Lots of options to play on VFD, which makes
it especially useful on a lathe or drill press.

[Clint Olver]

Nice job Mo, That thing is a beast!

C

[Mike Heidrick]

Why did you disable the brake again?

[mreza Salav]

Why did you disable the brake again?

I didn't disable any brakes. There is a foot brake which I can still use after turning the saw off (it doesn't have a micro-switch), I might add a switch to it later
but VFD stops the wheels fairly quickly that I don't see a need to use a foot brake.

[Mike Delyster]

That looks great Mreza, i really like the way you mounted that.

[Van Huskey]

Very nice install!!! Thanks for the documentation, we needed one of these to show how basically simple the wiring portion is.

[Mike Heidrick]

I didn't disable any brakes. There is a foot brake which I can still use after turning the saw off (it doesn't have a micro-switch), I might add a switch to it later
but VFD stops the wheels fairly quickly that I don't see a need to use a foot brake.

Did it turn the power off to the motor originally when you pressed the brake?

[James Heisbert]

Good wiring installations! They’re neatly done. I would like to have a VFD for my band saw too!

[Erik Loza]

Bravo, Mreza!

Erik Loza
Minimax USA

[Guy Belleman]

Mreza, where did you get the switch? I have a VFD on a 3/4HP lathe, but need to install a switch. Thanks.

[mreza Salav]

Thanks to all for the comments.


Mreza, where did you get the switch? I have a VFD on a 3/4HP lathe, but need to install a switch. Thanks.

No, there was no switch for doing this. As I said I might add it at some point and wire it to the VFD.


Did it turn the power off to the motor originally when you pressed the brake?

As I'm in Canada, I got it from http://www.busybeetools.com/categories/Wholesale/Switches/

[Guy Belleman]

The seller also just has the wires themselves connected to the VFD, but I like your connectors. Where did you get the wire terminal connectors? Thank-you for the information.

[Jeff Monson]

Very nice install!! I have another 3 phase machine coming this fall. I plan on using a VFD on it, can you explain the red and the black wires that you had attached to the light switch? Are they still attached and if so to what?

Thanks again for the great info.

[mreza Salav]

The seller also just has the wires themselves connected to the VFD, but I like your connectors. Where did you get the wire terminal connectors? Thank-you for the information.

You should be able to find terminal connectors in electrical supplies or those who sell trailer wiring stuff (here in Canada I bought it from Princess Auto).


Very nice install!! I have another 3 phase machine coming this fall. I plan on using a VFD on it, can you explain the red and the black wires that you had attached to the light switch? Are they still attached and if so to what?

Thanks again for the great info.

Those two wires are to terminals 3&5 which are for controlling the forward/reverse operation. Terminal 5 is the 12V line which if connected to terminal 3 will start the motor in forward operation (terminal 4 is for reverse).
One note: if this works backward you'd have to swap two of your output lines T1,T2,T3 that goes to the motor (e.g. swap T1 & T2).
Also, the default factory setting for function F3 (described on page 36 of manual) should be changed from 0 to 1 to have the the forward/reverse switch work this way.

[Mike Heidrick]

Using this latching switch, does the saw turn on if you have the switch in the on position and you loose and regain power? Or did you set set a code to prevent that?

What values did you set your internal braking codes too?

[mreza Salav]

Using this latching switch, does the saw turn on if you have the switch in the on position and you loose and regain power? Or did you set set a code to prevent that?

What values did you set your internal braking codes too?
The VFD can be programmed to what you like. The factory setting is, if there is a power loss less than 2 seconds the saw will automatically restart and there is no interruption basically,
if it is more then it will shut down and it won't restart even if the toggle switch is in ON position. You have to turn it off and then on (to reset the machine).
You can change to other settings as stated in the manual

[Irish Tomás Mac Giolla Ghunna]

Hello All .... Since these excellent 24" Italian 600 series bandsaws are much discussed / frequently for sale used cheap , and ... Are the next step up from a trade size machine to industrial series . I hope yall or ( mreza) don't mind me Bumping this thread up again . I have the same saw and am wondering what settings you've saved on your VFD . I looked through archives with no luck , Have you any info saved ? I.e How many RPM are you running the saw at , start ramp up time and electronic blade braking time. I'm also curious if you've fitted a start or emergency stop switch ? Thanks Tomas

[mreza Salav]

I will have to go and check, but I run it at whatever the motor spec said wanted it (50Hz IIRC); as for braking I set it to the minimum amount that the VFD drive allowed. (see page 36 for DC braking parameters and the corresponding pages it refers to). I think the default braking time was 0.5S and I set it to minimum. You can play with F_15 and F_16 to see which setting you like.

[Garfield M Duncan]

Hi all. Good Installation man :). But I would like to know if you had a lost in HP by using the VFD :confused:

[Mike Delyster]

No you don't loose any power by using a VFD. They are not like a rotary phase converter in that way.

[David Kumm]

No you don't loose any power by using a VFD. They are not like a rotary phase converter in that way.

It is a static converter that loses 1/3 power not a rotary. Keep in mind that if you plan to use a vfd the HP will go down as the speed slows although the torque should remain the same. Dave

[Tom M King]

mreza, Another, late, thank you for doing this thread. I'll be copying it for a Centauro 600, unless someone has a better idea 2-1/2 years later.

[Dennis Aspö]

I've been thinking of this as well because my bandsaws 3ph motor is too fast (probably 900rpm instead of 700rpm) and it's a direct drive saw. I have 3ph in my shop so I run it directly, I'd also like the motor breaking ability. And perhaps it could work in a pinch for metal cutting.

But alas it seems far more difficult to find 3ph/400V to 3ph/400V VFD, rather than a 1ph to 3ph 240V model. And the ones I find are way more expensive.

[Allan Speers]

I will have to go and check, but I run it at whatever the motor spec said wanted it (50Hz IIRC); as for braking I set it to the minimum amount that the VFD drive allowed. (see page 36 for DC braking parameters and the corresponding pages it refers to). I think the default braking time was 0.5S and I set it to minimum. You can play with F_15 and F_16 to see which setting you like.

Everyone should also note that you can increase braking time with these units, by adding a larger resistor. (Or just buying the optional TECO braking module, which is basically just a larger resistor.) I think the resistor dissipate heat, created by the dynamic braking. - but don't quote me on that. :rolleyes: