Wiring Advice

[kinsella]

Chaps
I recall we have one or two members who are expert on motors etc on this forum

I have a small lathe that i wish to power using a fan motor. Its only a small jewellers lathe so this is plently big. But i have no idea how to wire it. I can see that it works on both single and three phase. I'm assuming its configured to three phase.

Any experts out there who know how to wire to single phase? See attached the wiring diagram and below is the explanation of where each of the U, V W's are.

If its not clear in the photos. Top left is W2, then going acros the top middle top is U2 and top right is V2

bottom is from the left U1 then bottom middle is V1 and then bottom right W1

 

[dickm]

Not an expert, but I think you may be confusing voltage rating and phases. The diagram in the lid of the connector shows star and delta configurations, which allow it to run on either 230 or 440v, but only on 3-phase. To run that motor off single phase, you'd need an inverter. Which could be useful in your application, because it will give variable motor speed without (much) loss of torque across a wide range.

 

[kinsella]

Dick
More of an expert than I am. But first problem solved. It doesn't work on its own on single phase. Back to the drawing board!
Thanks.

 

[chrisliston]

Single phase to three phase inverters are available and would give you speed control, but It is also possible to run (generally small) three phase motors off single phase supplies using a capacitor between two of the incoming connections to create a 'lag' (essentially a fake second phase). I have wired motors like this before, however unfortunately generally new motors supplied with the correct capacitor.
If you wanted to persist with this one then I'm sure someone could help to select the right one, but surely there are several single phase motors out there which you could pick up for less money than either option. If you want the variable speed however, Dick's suggestion of inverter could be the way to go.

 

[kinsella]

Thanks Chaps
I work in a large company and i asked one of the maintenance guys to keep an eye out for a suitable motor that wasn't needed any more, i'll just ask him to make sure its single phase next time.

 

[woodpig]

Have a look at this thread, you'll just need a 30uf capacitor to run it once it's wired for 230V.

running-3-phase-motor-off-single-phase-y-or-delta-t85608.html

 

[bourbon]

Thanks Chaps
I work in a large company and i asked one of the maintenance guys to keep an eye out for a suitable motor that wasn't needed any more, i'll just ask him to make sure its single phase next time.

sounds Like your maintenance guy was having a laugh at your expense. Did he think that your house has three phase?

 

[porker]

Be interesting to see if the motor rotates in the direction of the arrow sticker. It is configured as delta with the links as shown but this is not normally how the links look (as you can see on the diagram in the cover). Moving the links to the more conventional arrangement for delta (three links in parallel) will make it rotate in the opposite direction.

 

[Myfordman]

But why would anyone wire the links that way to reverse it when all that is needed is to swap any two supply phases?

 

[kinsella]

Maybe thats why they are getting rid of it as they think its not working. I'm not going to get too excited about it. All i want is a working simple single phase motor, no capacitors etc. Will wait until one comes free.

 

[wizard]

The main problem I find with running 3 phase motors on single phase using a capacitor is getting them to start; they will start if you spin them fast enough under no load. They work fine when you get them going. If this was not a problem everyone would be doing this. The only reason I do it is to test them as a faulty motor can blow up an inverter as I have found out in the past.