Switch gear for 2 speed motor

[Tom Walker 1Participant @tomwalker1]

Harvest has intervened, and my electrician has been hard pressed. So motor not wired, but it is installed.

Please can I ask another question concerning the 2 speed motor wiring?

Here is a diagram from the motor. Does the connection instruction for the High Speed, the lower of the two diagrams, imply that when L1, L2 and L3 are connected to A2, B2 and C2,, A3, B3 and C3 are connected together?

I dont really understand how they are not connected together (for obvious reasons) in Low Speed, but are in High Speed. Does this have to be done in the switch? Thanks for guidance.

[EmgeeParticipant @emgee]

Yes Tom, that is the purpose of the speed change switch to link the 3's for high speed and remove the links when switched to Low speed.

Emgee

[John Sykes 1Participant @johnsykes1]

I have the Broook Motors book on Induction Motors (my father worked for them his entire career).

Pg 199 show precisely the wiring which Tom posted above. It is possible to wire up a star-delta switch to perform the two speed switching. Everything else can be left alone: the switch is interposed between the output of the existing contactor and the new two-speed motor. I can post a schematic if you're interested.

There's a supplier in Italy selling a star-delta rotary switch at a reasonable price

https://www.stockelettrico.com/products/14929-lovato-gx2012u-rotary-cam-switche-3p/

John

Edited By John Sykes 1 on 14/09/2020 17:07:27

Edited By John Sykes 1 on 14/09/2020 17:10:49

Edited By John Sykes 1 on 14/09/2020 17:11:09

[Clive FosterParticipant @clivefoster55965]

Common cam switches are fine for such duties too and may be less costly, maybe £5 to £15 range, depending on contact arrangements and whether they can be got naked without knobs, faceplate et al.

Connection layout for a cam switch at VN P11, top left, on this link **LINK** albeit with an off position in the middle which you don't want. Very expensive supplier!

Last cam switch I got was for a Bridgeport varispeed with a rather more complex set of connections. Took a deal of figuring out but I was able to find a standard part number rather than go the build your own route. Easily done but buying the bits separately comes a bit more expensive.

If you do use a common cam switch take care not to operate it with the motor running. Bade for the motor and terminal for the switch unless you are very lucky. The original on the a forementioned Bridgeport switch had sufferend in that way and been "creatively" reconnected so the machine could still run!

Clive

[EmgeeParticipant @emgee]

Posted by John Sykes 1 on 14/09/2020 17:04:41:

I have the Broook Motors book on Induction Motors (my father worked for them his entire career).

Pg 199 show precisely the wiring which Tom posted above. It is possible to wire up a star-delta switch to perform the two speed switching. Everything else can be left alone: the switch is interposed between the output of the existing contactor and the new two-speed motor. I can post a schematic if you're interested.

Hi John

It would be helpful to see the Brook motors schematic for the motor wiring if you can upload it.

Emgee

[Tom Walker 1Participant @tomwalker1]

Thank you very much indeed for all the above, which is very helpful.

[Tom Walker 1Participant @tomwalker1]

Posted by Emgee on 14/09/2020 23:33:59:

Posted by John Sykes 1 on 14/09/2020 17:04:41:

I have the Broook Motors book on Induction Motors (my father worked for them his entire career).

Pg 199 show precisely the wiring which Tom posted above. It is possible to wire up a star-delta switch to perform the two speed switching. Everything else can be left alone: the switch is interposed between the output of the existing contactor and the new two-speed motor. I can post a schematic if you're interested.

Hi John

It would be helpful to see the Brook motors schematic for the motor wiring if you can upload it.

Emgee

As Emgee says, John, it might help my cause (I need all the help I can get!).

If it is possible for you to upload a diagram it would be very interesting.

Thanks, Tom.

[John Sykes 1Participant @johnsykes1]

Having re-examined the Lovato switch data which I mentioned above, it appears that many of the change-over contacts are internally linked, so can't be used as such.

However, on the Lovato website there is a comprehensive list of their motor switches, and there is a three-postion pole-changing switch which does the job: it's schematic 13 and the switch reference is

GX1613U

There's one on ebay at the moment. You could tackle this with a cheaper / simpler switch but you'd then need additional contactors and both the cost & size would escalate.

I've scannned 40 pages of the Brook Motors book which include multiple motor configurations and the schematics of the old Brook control gear. There's a lot more data on their range of motors from the 1960's back, if anyone needs such info.

https://www.dropbox.com/s/z2g2r5ar6ojpkhr/Brook%20Motors%20data_1.pdf?dl=0

John

[Tom Walker 1Participant @tomwalker1]

Thank you John, for taking the trouble. Much appreciated.

Tom.

[EmgeeParticipant @emgee]

Thanks for the upload John, very useful set of schematics.

Emgee

[Tom Walker 1Participant @tomwalker1]

Just looking at Johns scan of the Brooks book.

Is my motor 2 speed (pole change) or 2 speed (dual wound).?

I presume from the red wiring diagram I posted, attached to my motor, that it is Pole Change, because of the linking together of A3, B3, and C3.

[Tom Walker 1Participant @tomwalker1]

Sorry, I posted too quickly, I can see that it is Pole Change.

[Clive FosterParticipant @clivefoster55965]

Given that contactors are relatively cheap these days consider fitting a simple change-over switch to control the actuator coils of a pair of contactors. One contactor carries the wiring for high speed and the other the wiring for low speed.

Big advantage for the novice or occasional electrician is that all the wiring arrangements are visible so its easy to trace and verify that its right. No teensy moulded plastic connector identification numbers to struggle to read whilst hoping the invisible innards of the switch are what you think they are.

Standard font for instruction leaflets seems to be 6 point. Not very mature eye friendly. If you get a leaflet. Modern trend seems to be to print on the inside of the box. Dark grey on grey.

Clive

[Clive FosterParticipant @clivefoster55965]

John

Thanks very much for the upload. Much appreciated. I have some of it on a rather aged leaflet printed in green that won't scan any sense.

Clive

[Brian MorehenParticipant @brianmorehen85290]

Hi Tom.

Once again so many ways this can be done , Wish I had Toms Motor on a bench with a few contactor;s so difficult to find the easiest way when you are not there the obvious and easiest is always the last idea that works A simple change over switch and 1 Relay for Slow and 1 for Fast..

Good luck looks like the answer is with you Brian

[Mike PooleParticipant @mikepoole82104]

I am not into taking photos but I find the camera on an iPhone very useful for taking a picture of motor plates in difficult to view positions or any other info label for that matter, the zoom on the photo viewer is very handy if I haven’t got my eye crutches with me. Useful in shops too if you want to read a product label. Can be useful for wiring but not always clear where a wire goes so swap one at a time if possible or make a drawing. Lots of specs. now don’t fit wire numbers so Numbered multicore not too bad but panel wiring all same colour and no labels.

Mike

[EmgeeParticipant @emgee]

Colchester used the simplest solution, a DOL starter and a pole changing High/Low switch.

Emgee

.

[Tom Walker 1Participant @tomwalker1]

Ah! Anyone got a spare one of Emgees switches?!

[John Sykes 1Participant @johnsykes1]

You already have the DOL.

The switch you need is here:

Ebay item no 202953411153 @ £36 delivered.

John

[Brian MorehenParticipant @brianmorehen85290]

Hi Tom

A three phase motor has 3 leads , connect each of your phases one to each lead and your motor will run if this runs o/k it may be running either slow or fast , which ever it is this will tell you which speed it is running at.

If the direction is wrong change over two of your incoming leads to reverse rotation. al O/k St test complete

disconnect your incoming supply and then reconnect to the other 3 leads your motor will either run fast or slow

2 test complete.,

Your Motor has two sets of windings one for slow and one for fast .

Hope this makes sence if not please come back regards Brian

[Tom Walker 1Participant @tomwalker1]

Posted by John Sykes 1 on 16/09/2020 17:14:29:

You already have the DOL.

The switch you need is here:

Ebay item no 202953411153 @ £36 delivered.

John

 

Thanks John, I have one on order.

 

 

Edited By Tom Walker 1 on 16/09/2020 21:52:47

[Tom Walker 1Participant @tomwalker1]

Posted by Brian Morehen on 16/09/2020 18:01:51:

 

Hi Tom

A three phase motor has 3 leads , connect each of your phases one to each lead and your motor will run if this runs o/k it may be running either slow or fast , which ever it is this will tell you which speed it is running at.

If the direction is wrong change over two of your incoming leads to reverse rotation. al O/k St test complete

disconnect your incoming supply and then reconnect to the other 3 leads your motor will either run fast or slow

2 test complete.,

Your Motor has two sets of win

or fast .

 

I get that, and that is the kind of "walk him through it" instructions I need!

BUT, according to the motor wiring diagram, you have to link the low speed posts together while in high speed.

 

 

Edited By Tom Walker 1 on 16/09/2020 21:49:22

Edited By Tom Walker 1 on 16/09/2020 21:50:53

[Brian MorehenParticipant @brianmorehen85290]

Hi Tom Are the following linked together A1 B! C! if so you may have a dual voltage motor , Is there anyone in your area who does motor repairs ? I feel if you take this motor into ther works they will be able sort this out quite easily.

Regards Brian

[John Sykes 1Participant @johnsykes1]

Brian:

I think Tom has this sorted . We've established that it's a pole-change two-speed motor, which required a slightly specialised switch to be interposed between the DOL starter & the motor.

John

[Brian MorehenParticipant @brianmorehen85290]

Look forward to a update at Last everything know working O/K

So many ways and possibilities to get this working.

Regards Brian

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