what do these 380v wiring colours mean, I want to use with a 220v vfd. it may have had speed control

[speedystu]

Hello, I am a woodworker who has got a large old power feed, its 380v and i want someone to rewire to a 220v vfd for me, can someone please tell me what these old colour codes mean. I bought the machine in Scotland.I can't find any easy diagrams online.I think its a good few years old.Thank you!

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[speedystu]

Fixed my breakdowns, one was an intermittent internal break in an encoder cable, other was a configuration problem.

You are correct that star-delta pole-changing is fundamentally different from star-delta starting. Star-delta starting is a method applied to a conventional 3-phase motor, while pole-changing is a function of a specially built 2-speed motor. What they have in common is the use of switching to rearrange the winding connections.

Star-delta starting is a basic soft-start method used with regular single-speed 3-phase motors that have one group of three windings rated for the full line-line voltage. When connected in star for starting, each 400V winding receives only 230V, reducing the starting current and torque. After a sufficient run-up time, the starter reconnects the windings into delta so that each winding receives the full 400V and full torque is available.

A pole-changing motor is specially constructed to deliver two speeds at the turn of a switch. The Dahlander configuration provides a simple and convienent way to alter the phasing and the voltage per winding with the minimum of switch contacts, suitable for motors with 2:1 speed ratio and windings rated for the line-neutral voltage. It does not offer a soft-start as such, which would require a more extensive switching system and probably be redundant on a typical small pole-changing motor.

Inverter drives make both techniques obsolete, because they can provide both soft starting and selectable fixed running speeds. For use with a 400V output inverter, a motor originally wired for star-delta starting can be left in delta (full power) and a Dahlander motor can be left in star (high speed) and controlled exclusively by the VFD. The standard motor could optionally be reconfigured for 690V in star, and the Dahlander motor 230V in delta, which is what we are looking to achieve here.

That's great you got the breakdowns sorted. This explanation is excellent, I will study it carefully. One question the star delta diagrams, those shapes(star and delta) are they theoretical or are they like that somewhere inside the casings? Im very grateful for the amazing expertise of you all, ill report back when i get the pics and multimeter, ill carefully remove it from the gearbox so i can look at it inside in the warmth with good light
thanks very much all!

 

[Simon47]

Star and Delta refer to the shape when drawn on the diagram.
Internally the windings are very different from the diagram, and realistically none of the arrangements look any different to each other. To start with, while each winding is shown as a single element on the diagram, in reality it will comprise multiple coils on the stator.
On a 2 pole motor, there will be two coils/phase - diametrically opposite each other in the stator. A 4 pole motor will have 4 coils - 90˚ apart round the stator. And so on. So a 4 pole 3 phase motor will have 12 coils in it - 3 sets (one set/phase) of 4 coils, with the 4 coils being connected in series and/or parallel according to the voltage rating needed and the coil design.

I had a bit of a look for some diagrams. This blog seems interesting, when you get to the bottom, click on the links for the next ones.
Then I came across this article where someone has rewound a motor. It's single phase, but the basic principles are the same for a 3 phase motor - they just have three phases worth of identical windings rather than different run and start (or run/start) windings.

 

[speedystu]

Star and Delta refer to the shape when drawn on the diagram.
Internally the windings are very different from the diagram, and realistically none of the arrangements look any different to each other. To start with, while each winding is shown as a single element on the diagram, in reality it will comprise multiple coils on the stator.
On a 2 pole motor, there will be two coils/phase - diametrically opposite each other in the stator. A 4 pole motor will have 4 coils - 90˚ apart round the stator. And so on. So a 4 pole 3 phase motor will have 12 coils in it - 3 sets (one set/phase) of 4 coils, with the 4 coils being connected in series and/or parallel according to the voltage rating needed and the coil design.

I had a bit of a look for some diagrams. This blog seems interesting, when you get to the bottom, click on the links for the next ones.
Then I came across this article where someone has rewound a motor. It's single phase, but the basic principles are the same for a 3 phase motor - they just have three phases worth of identical windings rather than different run and start (or run/start) windings.

Thanks again this is great. I'll check out the links now too. Will have pics and multimeter in the next few days. Looking forward to investigating this with all of your help. Thanks!!!

 

[speedystu]

Thanks again this is great. I'll check out the links now too. Will have pics and multimeter in the next few days. Looking forward to investigating this with all of your help. Thanks!!!

Hi all

I was able to remove the motor from the worm/bevel gears( i hope i did not damage them)

What should be my plan of attack, I am still waiting for a multimeter to arrive from screwfix.

How much of it should I dissassemble and take pics of?
Thanks all

 

[Darkwood]

Hi, I am a bit late to the party here and think Lucien has done as always an excellent job in helping you out, these kind of motors are ones I am not all too familiar with so I will reserve comment although I will make a point I don't think has been raised here.
Putting VSD's to run older motors comes with many risks, the windings themselves are not designed to cope with modern VSD control methods, breakdown of the windings can subsequently occur causing premature failure as well as circulating eddies running through the motor shaft and bearings which can see them fail prematurely too.

I would suggest because of the complexity and age of this motor you have here it would be infact cheaper (if we are talking time and money invested) to just buy a new motor and drive, a good motor service repair company may advice to replace the gears too or they may be able to adapt the new motor to suit to fit the old.

I would get a costing with options before you start going down the road of simply slapping a VSD control upfront of this motor or you may find out you are ending up paying out twice because of a bit of short sightedness.

PS - I will parrot Luciens concerns regarding compliance here although if this is a private project at home then you really are not subject to them, having said that though it is vital you have a very good knowledge of them and understand all the aspects of risk and safety that goes with changing/adapting the control system here, ignorance in this department could be life threatening in areas you fail to understand thus putting yourself at risk.

 

[speedystu]

Thanks for taking a look.

Yes agree "short sightedness" would be a pity but on this occasion

Hi, I am a bit late to the party here and think Lucien has done as always an excellent job in helping you out, these kind of motors are ones I am not all too familiar with so I will reserve comment although I will make a point I don't think has been raised here.
Putting VSD's to run older motors comes with many risks, the windings themselves are not designed to cope with modern VSD control methods, breakdown of the windings can subsequently occur causing premature failure as well as circulating eddies running through the motor shaft and bearings which can see them fail prematurely too.

I would suggest because of the complexity and age of this motor you have here it would be infact cheaper (if we are talking time and money invested) to just buy a new motor and drive, a good motor service repair company may advice to replace the gears too or they may be able to adapt the new motor to suit to fit the old.

I would get a costing with options before you start going down the road of simply slapping a VSD control upfront of this motor or you may find out you are ending up paying out twice because of a bit of short sightedness.

PS - I will parrot Luciens concerns regarding compliance here although if this is a private project at home then you really are not subject to them, having said that though it is vital you have a very good knowledge of them and understand all the aspects of risk and safety that goes with changing/adapting the control system here, ignorance in this department could be life threatening in areas you fail to understand thus putting yourself at risk.

Thanks for your input, we have spoken earlier in the thread about most of these items.

One question for me is if the motor is convertible (by me with the forums help) and works and fails prematurely will it take the vfd with it as well?
is it a very dangerous fire or electrical or mechanical hazard?

Safety is the highest concern - This actually to get a safety device working.

Is it worth opening it up so everyone can see what it is?
Id be interested to learn about the motor at least.

And then deciding a yay or naay on whether to proceed?

Ps I am very impressed by the forum and its members, a super professional and knowledgable resource.









That would be a waste straight out of the box,

 

[Simon47]

It would be unlikely to "take out" the VFD, more likely it would just trip.

 

[Megawatt]

View attachment 54624
Hello, I am a woodworker who has got a large old power feed, its 380v and i want someone to rewire to a 220v vfd for me, can someone please tell me what these old colour codes mean. I bought the machine in Scotland.I can't find any easy diagrams online.I think its a good few years old.Thank you!

1 2 3 4 5 6 7

Does that motors wires actually have numbers on them

 

[speedystu]

Does that motors wires actually have numbers on them

The wires going into the motor do not have any visable numbers on them.
I have counted all the wires and marked where they are connected.

 

[Lucien Nunes]

The colours of the outgoing cables don't tell us anything; they are the usual harmonised phase colours (black, brown, grey) for one winding group, and three other random colours for the other group. You can remove these for now as they will be in the way, but don't disturb the internal connections from the windings.

I hadn't been able to see that there were 9 winding ends in the terminal box. If the two leads on each of UA, VA, WA are the corners of the delta (a.k.a. U1, V1, W1) then those simply need making up into different pairs, and the 230V reconfiguration is complete without having to open the motor. If they are the edges (a.k.a. U2, V2, W2) and the single leads on UB, VB, WB are internally jointed to the corners, we're no further forward and need to get at those internal joints. So it looks like we have a 50% chance that it's a doddle. Now I have to think of a simple test to identify them with minimal equipment and no 3-phase mains.

Referring back to your previous post, no, there's no physical manifestation of star or delta layout in the windings. Those shapes refer to the appearance of the theoretical circuit diagram when particular combinations of winding ends are connected together.

Darkwood makes a good point; not all motors are happy with VFD output waveforms. The short risetimes stress the insulation and older motors sometimes breaks down as a result. I've never actually had this problem myself yet, so I tend to overlook it.

 

[Darkwood]

With regards to the VSD failing if the windings do, some smaller cost effective VSD are not short circuit protected and will likely fail in the event of a short, I found this particularly on small models converting 1ph to 3ph, do not assume as is usual for VSD's that they are protected, I would confirm it before purchasing.

 

[speedystu]

Thanks for that

Think someone did a bodge fix (semi permanent fix) on the shaft instead of a set screw, if we have to take apart ill drill and retap. Will have a multimeter soon, will patiently await further instructions. As always thanks a million, I have learnt loads already

 

[Megawatt]

The colours of the outgoing cables don't tell us anything; they are the usual harmonised phase colours (black, brown, grey) for one winding group, and three other random colours for the other group. You can remove these for now as they will be in the way, but don't disturb the internal connections from the windings.

I hadn't been able to see that there were 9 winding ends in the terminal box. If the two leads on each of UA, VA, WA are the corners of the delta (a.k.a. U1, V1, W1) then those simply need making up into different pairs, and the 230V reconfiguration is complete without having to open the motor. If they are the edges (a.k.a. U2, V2, W2) and the single leads on UB, VB, WB are internally jointed to the corners, we're no further forward and need to get at those internal joints. So it looks like we have a 50% chance that it's a doddle. Now I have to think of a simple test to identify them with minimal equipment and no 3-phase mains.

Referring back to your previous post, no, there's no physical manifestation of star or delta layout in the windings. Those shapes refer to the appearance of the theoretical circuit diagram when particular combinations of winding ends are connected together.

Darkwood makes a good point; not all motors are happy with VFD output waveforms. The short risetimes stress the insulation and older motors sometimes breaks down as a result. I've never actually had this problem myself yet, so I tend to overlook it.

Couldn’t the motor be wired star or delta using the factory jumpers and VFD’s can’t be put in pipe with other motors or bundled up, the EMF really makes the VFD’s do crazy things

 

[speedystu]

Met with these very important motors this eve with the kids. Was not that uber confident when I looked up and saw big looking pillow block bearings and the open air basket swinging at full height!! back down to earth with no bang thankfully!!!!
Thanks all for your help so far!!

 

[Lucien Nunes]

It's sometimes a surprise just how safe fairground rides are overall. A report by the HSE a few years back found that people were statistically 12 times less likely to meet a serious accident riding the machines than while walking to the ground in the first place. And, that includes the numpties who force their safety bars open and climb out of their seats etc. If you discount those, it's safer still.

I can't get used to these big VFDs, they just don't go with the smell of burgers, candy floss and mown grass. Give me a 10hp 110V DC shunt motor, a faceplate starter and a Gardner 5LW rumbling gently in the background. I've got some video I shot 30 years ago at dusk, the whole gaff ablaze with traditional coloured filament lamps, packed with punters and throbbing to proper rock'n'roll. There's a magical moment as I'm focused on the ammeter on the old Lister switchboard watching it swing over and hearing the rack on the JP4 opening up as we pull away on 2nd stud. Extreme thrill stuff is all very well but it hasn't got the soul.