That suds pump.

[DavidA]

John (Doubleboost),

In your video covering the construction of a tank for your Harrison lathe/ Chester mill you mention that it has been converted to single phase.

Was it originally a star wound three phase motor or a delta wound one.

I suppose the question is,  are you just running the original (with the aid of the capacitor) at half voltage using  the delta winding configuration ?

Dave.

[doubleboost]

[DavidA]

Thanks for the link.  I did recall you mentioned a video,  but couldn't find it.

Dave.

[Manxmodder]

Great video,John. That shows and explains all the points very clearly  .....OZ.

[hermetic]

Just to clarify the above point, motors are not "star" or "delta" wound, they are all the same, it is the way they are connected to the supply that makes the difference, hence we see John changing the connections from star to delta. There are some motors where all the coil ends are not brought into the connector block, these function in either star or delta, but cannot be changed over from one to the other.
Phil

[John Rudd]

There are some motors where all the coil ends are not brought into the connector block, these function in either star or delta, but cannot be changed over from one to the other.
Phil

If one is savvy enough, the Star point can be brought out, the ends split, the motor then rewired for Delta....

[hermetic]

Quite right John, they can, but it usually means cutting into the binding, and then seperating the ends, adding some tails,insulating and rebinding. Not really a job for the faint hearted, though as you say, it can be done.
Phil

[John Rudd]

Phil,
Trouble is we ( savvy ones like you and me ) know this sort of thing and tend to take these things in our stride whereas the Joe in the street wouldn't know any better....so it's only thru forums like this that the knowledge can be put to use....words like 'wound' tend to infer exactly that...and it is taken that the motor is a Delta or Star wound motor rather than how the windings are or can be configured.....
Hats off to John, DB for showing how to mod a coolant pump motor to run single phase .......

[Pete.]

Just to clarify the above point, motors are not "star" or "delta" wound, they are all the same, it is the way they are connected to the supply that makes the difference, hence we see John changing the connections from star to delta. There are some motors where all the coil ends are not brought into the connector block, these function in either star or delta, but cannot be changed over from one to the other.
Phil

That's true 'star wound' or 'delta wound' are terms that are commonly used. Just as you might say 'doing the hoovering', even though you might not actually be using a Hoover.

[hermetic]

Hi John, Yes I agree, doubleboosts video does a great service in showing how to reconnect a motor. but I fight a bit shy of telling anyone to dive into the binding and start soldering. the chances of damaging the insulating varnish are quite high if you havent done it before(or been trained to do it), and it might wreck an otherwise good motor which could be put to another purpose. Then there is the safety aspect. I would quite happily do it myself, or show someone how to do it, but from the safety point of view, I think it is best to find another motor!
Phil

[DavidA]

So let's approach it from a different angle.

If there are only three wires coming out from the windings to a connector block,  how do you know whether it is connected in star or delta ?

Dave

[John Rudd]

I'd say you cannot take it for granted either way.....


The motor Id plate would give you a clue, if it's 415 3phase only, then star, 230v 3phase then Delta

The dual motors I have encountered have had all six ends brought out....

[Will_D]

Ohms law should help:

Star: You will read the Rx of two windings across two connetors

Delta: You will read th Rx of one winding.

The spec pate should tell you the VA of the motor

[DavidA]

John,

... if it's 415 3phase only, then star,..

That's what I was afraid off.

I was hoping to be able to run my Emco milling attachment via an artificial phase (capacitor ) from 230 Volt single phase.
But it won't work as I can't get to the other ends of the windings.

Wil,

I'll check the plate.  But I don't think I'll be able to do it anyway.

I'm just going to have to spend the money and get a convertor.

Dave.

[Pete.]

Would it matter much if you can a 415v suds pump on 240v though? It's not like the load varies much or you have to worry about low torque.

[DavidA]

Pete,

It might be worth a try.  At least it won't cost anything as I have a few capacitors I can use.

I suppose that as long as I didn't try to chew off too much metal at once the speed wouldn't drop too much.

Dave.


Additional.

Just re read your last.  You do realise that it is the Emco milling attachment that I was hoping to
run,  not a suds pump ? This is why I was a bit worried about running it at half voltage.

[awemawson]

You just need a small 240 - 415 transformer then the capacitor mod and your pump should run fine. There are many 415-240 small transformers kicking around that have been used when a three phase machine needs a 240 single phase feed to something and remember transformer are bi-directional 

[DavidA]

Andrew,

...your pump should run fine...

It's the milling machine attachment I was considering running,  not the pum.
I used the pump at the beginning just as an example.

Re the transformer.

Maybe I could use a standard 220 to 110 site transformer in reverse. As a 220 to 415.

Only downside I can see is that I would have to use >415 Volt capacitors.

What do you think ?

Dave.

[John Rudd]

Dave,
If you are going to use a cap system to power your mill, I'd be inclined to go the safe route and buy.....https://www.machinemart.co.uk/shop/product/details/pc-20-2hp-phase-converter?da=1&TC=SRC-phase%20convertor. one of them.....much safer than trying to jury rig something with component parts of questionable origin.....   

[awemawson]

No that won't work as neither winding is 415 v rated - you need a 240 -> 415 transformer. At a push you can use a 240 v isolating transformer wired as an auto transformer so primary and secondary are in series - it will give you 480 unless there's a tapping on one of the windings that's lower but many motors are ok on that.

Remember - volts hurt - especially when they gang up on you

[DavidA]

John,

Thanks for the link.  But there had to be a snag. I downloaded the manual for it and found this warning at the top.

...It is not desirable for use with stop start operations...

Ah well,  back to the drawing board.

Andrew,

The voltage rating could be a problem.

So,  I'll go back to the Transwave rotary converter option.

Easiest way out.  Sadly,  the most expensive .

But like a dog, convertors are not just for Christmas.

Dave

[John Rudd]

Dave,
Have a look here..... http://www.phase-a-matic.com/StaticDescription.htm

They claim no issue with a lathe/mill etc.....

[hermetic]

 DavidA, drives direct do a 240v single phase to 415v 3 phase VFD , any use?
Phil

[DavidA]

John,

Looking at the details it doesn't look very promising.

Either you are stuck with obtaining only 2/3 of the single phase power,  or you need to run an auxiliary motor as often described in the many sites on line.

Phil,

Thanks for that link.

But as I want to be able to have a ring of sockets around the workshop and be able to plug in any of my three phase motors without worrying about 'is it compatible',  I've decided to spend the money and go for the Transwave rotary converter ala DoubleBoost.

Dave.

[John Rudd]

I've decided to spend the money and go for the Transwave rotary converter ala DoubleBoost.

Dave.

I hope you and your new converter have a happy relationship.....