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]

45 minutes ago, Rooster35236 said:

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

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.

 

1 hour ago, 480volt said:

What does the controller do  to make it worth retaining?

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.

[480volt]

A few observations:

The motor rating plate indicates that it is single-voltage. This is not surprising as the controller voltage range isn’t that great.

Dual-voltage three phase motors sold in the US are usually nine-lead, where each winding is divided in half and you connect them either in series (hi voltage) or parallel (low voltage). European motors are more commonly wound so that you can configure them as wye or delta to change the voltage. I have been a commercial/industrial electrician in California for decades and have yet to come across one of these.

Somewhere, I have seen a reference from a manufacturer directing the user to add a capacitor to allow a three-phase motor to run on single-phase, however, if the motor is not designed for this it will overheat.

Looks like you have to run the style of motor that came with it because of the clutch/brake setup. It would be a long shot, but maybe one of the dealers on this board has a 120V single-phase version of this motor? Then you may only need to boost the voltage to the controller.

Is the circuit available dedicated or  is it sharing with other machines?

Assuming you do get it to work, you will be relying on old electronics that likely need a backup machine to cannibalize for parts if something fails. Just some factors to weigh before you get into it for a lot of money.

 

[Gymnast]

On ‎1‎/‎6‎/‎2020 at 4:12 PM, 480volt said:

The motor rating plate indicates that it is single-voltage.

Well - I read Pole 2 Ph. 3.  on the motor rating plate. A 2-pole motor with 3 phases. I get the current rating right with a cosphi about 0.8 for such a motor and resonalbe losses. And the first Photo show 3 leads to the motor. That is why I belived it should be a 3-phase motor with a phase-phase voltage of 220 V. Apparently you read something else.

You are right, that the motor can very well be arranged with the connections to the windings in another way than I anticipated, so you cannot make a triangle connection. But then you can do the parallel connection and go from there. I think it is possible to make the motor run with a capacitor, if you accept that the motor do not have the same shaft power anymore, and you do need to have an applicable motor protection circuit. You only need a small capacitor in order for the motor to start. But it may only have left half motor shaft power after you have finished what to do here!

In general aggree with you, that keeping old electronics and motor should be considered before investing too much in it.

[Handstitched]

I know this is a different machine,but similar issue with voltages,  I do have a USM 20 T  Hyptronic press,but its 3Ph, I can't use it .

We dont have 3 phase anywhere in the street . I also considered a converter, but, the power going to my workshop comes from the house, its 10A  ( 240v) , and the converter requires 15A ( 240v Australia) . The next option is to have 15A   installed in the workshop at great expense, with no guarantee  of success . Its the ' start up' that will draw the most current as the fly wheel inside the machine is massive  and very heavy, and I don't think a converter will cut it.  

I was once quoted over $ 1000- to change the motor to single ph. 

On 1/8/2020 at 6:52 AM, Gymnast said:

In general aggree with you, that keeping old electronics and motor should be considered before investing too much in it.

I'm thinking the same. I'll just buy a cheap 3 ph generator, when I win Lotto 

HS