Adapting a 3 phase industrial machine to single phase

[Gareth Blackstock]

Hello,

I am hoping this is in the correct forum. To start, I acquired a film processing machine that runs on 3 phase. Now before getting the machine I fully understood it's power requirements and the cost of getting 3 phase installed at my house. I figured as processors are mostly a few pumps and lots of motors, I would be able to find a "workaround" like finding what motor draws the most and replace it, or re-wire the machine.

Examining the machine, I discovered there are 4 motors, and 2 pumps, only one motor is 3 phase, all others are single phase. There are two 3 phase connections, one that was hardwired and cut, the second is a 3 phase plug on the machine. I have attached some pics to show the different power inputs. I have inquired locally of some sparky's to see if they would help, I even offered to pay more than their call out fee, but all declined. One said that if I did the wiring he would attend to test it for safety before flicking the switch.

Here is the question: If I replace the biggest current and voltage drawing motors, at least the 415v 3 phase, and the plugs and fuses...can I fool the machine into running happily on single phase? If the machine did not need to draw 415volts could it still run on reduced voltage or would the collective draw of the other motors still require alot of voltage, hence needing 3 phase regardless? Or can replace the biggest voltage drawing motor and simply purchase one of the converters linked below? That way the heavy duty motors are replaced and I can still utilise the original wiring.

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The machine I think is very well made, these were very expensive when new. The wiring looks to be professionally installed, and it appears the manufacturer installed quality items. I would hate to have to rip it all out and re-wire it for single phase wiring... which I reckon I am capable of doing, basically wiring the motors and pumps to a switch board, similarly to how it already is, installing my own switches, however I would perhaps lose some existing capabilities. Running the machine essentially needs a motor to run the processor, the two pumps can be left off while the processor is running, they simply filter the developing liquid, this can be done later. Once the film is developed a vacuum motor needs to run, as does a hot air blower, and a take-up motor (winds the film onto a spool)

I cannot afford to spend $$$$ but a few hundred is certainly doable.
These are the motors and pumps, one I cannot access but I think it is also a 3 phase motor.
Main drive motor:
Brand: Parvalux S/N: 12L1
Volts: 200/220 Amps: .9
Phase: 1 H/P: 1/6
Watts: 125 RPM: 3000

Dryer motor:
Brand: BKP S/N:
Volts: 415 Amps: .75
Phase: 3 H/P:
Watts: 180 RPM: 1440

Take-up motor:
Brand: Parvalux S/N: SD 8S
Volts: 200/240 Amps: .33
Phase: 1 H/P: 1/6
Watts: RPM: 1400

Pumps: x2
Brand: Emapompe S/N: PO90
Volts: 220
Phase: 1

Main fuse board

3 phase power input -fuses top left, main power switch bottom right

This is the 2nd 3 phase power input, these wires connect to the main fuse board, first pic

The below connector block links all the various motors and pumps

 

[marcuswareham]

It looks like there is enough space inside the machine for modifications which is handy

You would need to replace the 3 phase motors as they require 3 phases 120 degrees apart in order to turn, they work differently to other motors and have a set of windings for each phase, its the phase rotation which cause it to turn

If you found suitable speed, toruqe and HP single phase motor replacements that would be a way to go, then everything inside the machine is running on 230v, the accumulative current demand as you say just needs to be worked out and then you ensure you have installed or can get installed a circuit with enough current carrying capability to handle it. Also worth noting a single phase replacement motor may draw more current so the wiring inside the machine might need to be upgraded

Thats my take on the motor side of it, the control side of it would need to be verified as to how it is configured, But I suspect a single phase can be supplied to all the relays etc doing the switching and if not already there a single phase AC to DC power supply could be sourced for the PCB

 

[brianmoooore]

Any pics of the drier motor, especially its rating plate. If it can be wired star and delta, it may be possible to reuse it.

 

[Gareth Blackstock]

Hello,

Thanks for the replies, I like Marcuswareham's suggestion, it makes sense to me, replace motor and fuses, and I still like the idea of installing switches so I can isolate big draw motors or pumps to ease overall current etc.... I am still learning about this as I go.

For Brianmoooore I have attached a pic of the plate on the big draw motor. I reckon if I sell it I can cover the cost easily of a replacement single phase motor. Part of the drying cabinet, what this motor blow air through, are also some big elements that heat up.. they are probably 3 phase too. But its a start.

Cheers, guys, enjoy time with your families... I better go attend to mine..

Gareth

 

[brianmoooore]

Dryer motor:
Brand: BKP S/N:
Volts: 415 Amps: .75
Phase: 3 H/P:
Watts: 180 RPM: 1440

Not reading carefully enough, as usual, I took this to be a 3HP motor, not the fractional HP motor it actually is.
A single phase replacement for this will be relatively cheap to buy new, unlike a 3HP single phase motor, so that's the way to go.
The first thing you're going to have to do is to reverse engineer those connection and control panels, to produce an accurate circuit diagram of what you have. From there, it should be relatively simple to see whether it can be adapted for single phase.

 

[Gareth Blackstock]

A quick update, I got a closer look at the power supply wiring, bottom left, and from the small amount of reading I have been doing on 3 phase power supply, I should be able to re-wire as per the bottom right diagram (as long as I isolate the 3 phase motors by initially removing the fuse, I can replace with single phase motors later)

Before I flick the switch I will isolate not only the 3 phase motors, but also the single phase pumps, at least until I can get it working, then try with pumps de-isolated to ensure I do not blow a fuse.

I am hoping you guys might check my suggested re-wire?

Cheers, Gareth

 

[ozmatt]

Any particular reason why you don't just install a VFD to generate 3PH from the 1PH supply ?

 

[Lister1987]

Be very careful modifying this (or any) machine. Whilst definitely outside of that EU, Australia does follow tht fundamentals in both the safety directive and machinery directive, you'll likely find that thr minute you step outside of 'maintainance' and into 'modification' that you inherit a whole buttload of responsibility and liability (even if it's just for your use).

I'd speak with your local WHS organisations and see where you stand before doing anything.

 

[Gareth Blackstock]

Hello,
I had an electrician check the machine while he was at my house on a wiring job. He had not seen a VFD before, and was curious as to why the terminals had no labels, so he is researching which terminals are which.
So i have a vfd standing by. He suggested i wire 240 volt to the machine, pull fuses on all non essential motors as a way of starting it and checking its function.

I did that and the machine is working well, not all its functions, but its a start.

I hear what you are saying by modifying the machine, legally and safety wise. However, the company that built it is long gone, no manuals exist, and as i cannot afford an electrical enginner to spend a month on it, like most people i have to find a work around. I have already found some adaptions to the machine, presumably by an electrician, yet they left no info on the machine of their alteration. Odd and illegal i think.

Gareth

 

[slartybartfast]

Any particular reason why you don't just install a VFD to generate 3PH from the 1PH supply ?

Just what I was going to suggest. It maybe that the overall load precludes this and would blow a 1P 100A fuse. Could also be cost prohibitive.

 

[James]

Just what I was going to suggest. It maybe that the overall load precludes this and would blow a 1P 100A fuse. Could also be cost prohibitive.

This is an old thread but I feel I should point out that most 3 have machines are looking for 400v between phases.
by using an inverter from 230v input, you only get 230v between phases and would then need to modify the wiring of all the motors to suit.
also you can have problems with other devices that are expecting a higher voltage.

 

[slartybartfast]

This is an old thread but I feel I should point out that most 3 have machines are looking for 400v between phases.
by using an inverter from 230v input, you only get 230v between phases and would then need to modify the wiring of all the motors to suit.
also you can have problems with other devices that are expecting a higher voltage.

Yes but you can step voltage up easily with AC using a transformer.

 

[Gareth Blackstock]

Hello,
Thanks for the input. James, I initially planned to use the VFD to try and fool the machine's electronics into thinking it was getting the full measure of voltage, I also pulled the fuses on the two motors that were 3 phase. It worked enough for me to see if all parts of the machine were working. I then removed the 3 phase connection and wired in single phase directly. With the 3 phase motors still disconnected, I managed to get the machine running using just single phase. So my next step would either be replacing the 3 phase motors with single phase equivalents, and installing switches to manually control which components run and when. Doing so removes the automated benefits of the machine, but allows me to control the voltage draw by choosing what to run and when.

And also when I installed all fuses and tried to run the machine on the VFD, the VFD reported "under voltage at source"

However, slartybartfast has an interesting suggestion.... if I was to install a step up transformer.... what type? There are quite a few.... Would I install it between the single phase source (powerpoint) and the VFD? Then would I be able to run up to 2 three phase motors as well as the other components?

Cheers, Gareth

 

[slartybartfast]

Hello,
Thanks for the input. James, I initially planned to use the VFD to try and fool the machine's electronics into thinking it was getting the full measure of voltage, I also pulled the fuses on the two motors that were 3 phase. It worked enough for me to see if all parts of the machine were working. I then removed the 3 phase connection and wired in single phase directly. With the 3 phase motors still disconnected, I managed to get the machine running using just single phase. So my next step would either be replacing the 3 phase motors with single phase equivalents, and installing switches to manually control which components run and when. Doing so removes the automated benefits of the machine, but allows me to control the voltage draw by choosing what to run and when.

And also when I installed all fuses and tried to run the machine on the VFD, the VFD reported "under voltage at source"

However, slartybartfast has an interesting suggestion.... if I was to install a step up transformer.... what type? There are quite a few.... Would I install it between the single phase source (powerpoint) and the VFD? Then would I be able to run up to 2 three phase motors as well as the other components?

Cheers, Gareth

Some interesting design decisions to be made. I would suggest that this is not the forum for those as is well out outside of normal electrician territory.

 

[Gareth Blackstock]

Really? The step up transformer question seems well placed in this forum, do you know of a type that could be used before a VFD?