3Ph Controller on Single Phase

[Rooster35236]

Recently acquired a Singer 591 with the computer/controller (491UTT), would really like to have the controller be usable. I should be able to get the unit running with a vfd like this one. Has anyone done this successfully and what/if any are the drawbacks of running a machine through an inverter?

Thanks for all the help!

edit: The VFD would be sending power to the clutch motor and the controller.

Edited January 5, 2020 by Rooster35236

[Gymnast]

I have read quite many posts on motors to sewing machines. But I have never seen this being tried. Actually it should also be possible with a clutch motor to do this and afterwords engage the clutch all the time.

The VFD do not come with a system to connect to a foot pedal. So you need to make something extra for that to give control input to the VFD. Then I think, that the servo motors to sewing machines are quite cheep with motor and drive in all. So to install a VFD can be a more expensive and troublesome solution.

[480volt]

Is this a three-phase machine you are trying to power off single-phase?

[Gymnast]

  On 1/5/2020 at 5:46 PM, Rooster35236 said:

edit: The VFD would be sending power to the clutch motor and the controller.

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I think this could be problematic to use the VFD to provide power to the controller. Then you need a filter too. But I guess, that the power to the controller part may already be taken from one phase only. This could be checked. What is the input voltage specification to the machine?

[480volt]

The controller may or may not like the square-wave output from the vfd, and you would not be able to use it for speed control. The electronics in three-phase equipment invariably is single-phase with a transformer connected across two legs. Only the motor needs actual three-phase. What does the controller do  to make it worth retaining?

[Rooster35236]

The motor that is on there is very similar to most of my other clutch motors - 550w/1/2 hp just that it is 3 phase.

The controller I am still researching but there is a voltage selector 190/208/220/240. From what I have gathered so far is the motor draws power and then feeds to the controller. I have not totally poured over  the schematics for the controller yet. I will get pics and full details shortly though.

 

  On 1/5/2020 at 7:01 PM, 480volt said:

What does the controller do  to make it worth retaining?

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Thread trimming and backtacking would be huge for us and programmable stitches would make applying clothing labels run so much faster.

http://hensewfiles.com/PDFs/SINGER 491UTT.pdf

Edited January 5, 2020 by Rooster35236

[Gymnast]

Is it 110 V single phase, that you would prefer to use for it? Or do you have 220 V too?

If you only got 110 V, then you need a step up transformer for the electronics.

Is it OK for you to continue to use the clutch motor as it is. Or do you want to convert to servo motor operation? It may be able to run resonable by adding a capacitor only - perhaps with some extra cooling.

I guess you need an electrician or someone with knowleledge of electric systems to help you in a conversion. It seems to be possible without a VLT.

[480volt]

Looks like there are a lot of features on this machine. Do you know if the electronics check out?

The wiring diagram in the link doesn’t give you much to go on, just the pin-outs for the controller. Is there a diagram of the machine overall? First thing I look for is where L1, L2, L3 connect. If the controller can be separated from the motor, I’d do just that, feed the motor from a vfd or rpc and feed the controller from the same circuit feeling the phase converter.

But I’m just speculating. The thing may just run fine off the vfd. The person you may want to ask is Gottaknow, he is the head mechanic for a domestic garment manufacturer, and is a wealth of information on some of the more arcane aspects of industrial machines. He visited last about a week ago.

[Rooster35236]

@GymnastRunning a 220 line to the sewing studio would not be feasible way too far from the breaker panel, lol

I would have to keep the clutch motor a servo and the controller would be a nightmare to try and wire up correctly. This place is really old and it does not have the best feed, we get quite a few surges which cause slight brownouts, (I really should put a power conditioner in) I would hate to blow a capacitor that big just from dirty power.

@480volt Funny story, our seamstress never used an industrial machine before she started here, 2 weeks after she started she bought a Sail-Rite lockstitch. Then she messages over Christmas break that she is taking a trip to Georgia to pick up a Pfaff 5483 chainstitch (same as we have here) and the lady had some other machines she was selling (Rimoldi 627 overlock, Singer300w long arm (5 needle tuck and roll), Consew 325 chainstitch and this Singer 591) We talked her way down because we said we would take all of them. She told us she got them from an auction and they were in a running factory, the Pfaff and the Rimoldi run great the 300W runs but have not tested totally, have to order a whole lot of thread for that one. So I really do not see any issues at this point.

Hopefully @gottaknow will be able to shed a little more light onto this for me.

Check out the pics for some of the wiring on this. (The 8G black wire is an extension cord somebody ran from the fuse box)

Edited January 6, 2020 by Rooster35236

[Gymnast]

In the last Photo, you got a knob able to control max speed. According to manual, it seem to be done by means of an electronic control of the clutch. So you got some more advanced speed control this way. I guess the normal way is, that a clutch is directly controlled by a food pedal, but this cannot be the case here.

It is not possible for you, to use a VFD for this conversion.

If at all possible - I think you need someone to look at it. You need to separate the connections of supply to the motor and the controller. Then you need a step up transformer for the controller part. You need to change the connection of the windings in the motor box from star to triangle. And then you need to add a capacitor to make the motor run from one phase. The motor will get hotter and consume more energy, so I will not be quite sure that this will work. If you are a bit lucky, this could work.