Strange Large Single Phase motor??

[flyingsparks]

Hi all. I have a large motor which I need to connect up. Its for grinding wheat on a mill. The rating plate says 240V single phase. 25A FLC. 1440 RPM However inside the terminal box there are the following connections. Z1 & Z2. A1, A2, A3, A4 and 1 & 3. This motor was before I saw it connected to a handle type of starter, similar to the old star / delta starters. Can someone point me in the right direction as to how to connect it, and on a new starter suitable for it. Not come across one like this before!!

Thanks very much. Chris

 

[ricicle]

Sounds like a capacitor start and/or run or possible split phase motor. The Z connections are normally the start winding.

A1 A2 possibly main winding. 1 and 3 could be a capacitor. A3 and A4 maybe another speed or second capacitor.

Thats as much as I remember off the top of my head but it's a start.

 

[flyingsparks]

OK Thanks. I do hope it isn't split phase! It doesnt say 480V anywhere on the plate, but did just find this link..

http://www.homeworkshop.org.uk/index.php?option=com_agora&task=topic&id=888&p=2860

Any more help greatly appreciated.

 

[flyingsparks]

Oh and I couldnt see a capacitor anywhere!

 

[Taylortwocities]

Have a look at this thread. Especially the last post. Some clues for you
http://www.homeworkshop.org.uk/index.php?option=com_agora&task=topic&id=888&p=2860

 

[flyingsparks]

Yes was just reading that thread! I guess my motor is also a Brook Crompton although its not here to see that. Now to find a compatable starter..

 

[magnicon]

Interesting,I have seen several motors on small feed mills in the past rated 480/960 volt,with a hand cranked series parallel starter.These were all installed in rural areas where only a 3 wire single phase supply was available.Your motor sounds like a lower voltage version these,has it got a centrifugal switch on the end of it ?.

 

[flyingsparks]

Well I phoned Brook Crompton today and spoke to them and yes I believe Z1 and Z2 is a start winding with a centrifugal switch. There was an old series parallel starter on it before I saw it yes, and I think I may have just found the modern equivalent starter for it.

http://www.cromptoncontrols.co.uk/product/standard-starters/3sp2-s

 

[flyingsparks]

Also, the chap thought that the overload required would be half of the FLC as the windings are paralleled up?

 

[magnicon]

I still think you will need a capacitor in series with the start winding,Please do not be tempted to put it DOL in parallel or you will most likely take out your service fuse.

 

[bernardgreen]

I still think you will need a capacitor in series with the start winding,Please do not be tempted to put it DOL in parallel or you will most likely take out your service fuse.

Some motors are constructed with the start winding mechanically out of phase with the run winding and do not need a capacitor. In fact a capacitor may even negate the mechanical phase shift and delay or prevent the motor reaching normal speed.

Use the data sheet and/or technical assist from the manufacturers to be 100% certain of getting it (almost) right.

 

[andyubbi]

hi there,
i dont know if you have sorted your problem but i just stumbled across this topic and i may be able to help!
i specialise in electric motor repair and don't have a problem in sharing info!
what you have is a series/parallell motor that needs a special starter and also start and run capacitors for it to work.
let me know if you require any further info.

regards

andy

 

[ban-all-sheds]

i dont know if you have sorted your problem

After a year?

If he didn't sort it then he will have got a different motor by now.

 

[flyingsparks]

Hi Andy yes sorted it out now!! Cheers anyway.