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Reversing Motor

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Keith Jenkins 104/02/2021 16:55:47
24 forum posts
4 photos

Hi All,

My first post here but I have been looking through the forums for a long time and I know there is a lot of knowledgeable people here.

I have been searing the net for a few hours per night trying to find information on an AER single phase 750w 1425rpm motor, cap start cap run on my lathe and want to fit a forward reverse switch, the switch didn't come with great instructions and I can not find any info about the AER motor, so I wondered if someone here had any knowledge of motor reversing and switches.

Under the motor cover the wires are K, AZ, A, Z, S. The cover says to swop Yellow and Blue to reverse the motor but that just pops the trip.

Any help would be much appreciated. I can post more details, what ever is required.

Many thanks

Oldiron04/02/2021 17:03:55
763 forum posts
23 photos

Hi Keith welcome to the forum. A picture speaks a 1000 words. A picture of the connections in the box would maybe help to get a good answer. Post pics to forum


Edited By Oldiron on 04/02/2021 17:04:43

Les Jones 104/02/2021 17:11:06
2225 forum posts
153 photos

Do you have a multimeter to work out the truth table for the switch and to identify the main an auxiliary windings on the motor ? Post as much information as you have on the switch and motor and pictures of the connection box on the motor and the switch showing any number / letter marking on the switch. Is the switch a two position or three position switch ?


Dave Halford04/02/2021 17:11:49
1395 forum posts
12 photos

Have you tried :-

power down

flip reversing switch

power up?

Some changeover switches do not have a dead spot so you get a momentary full short under power and anyway switching under load fries the contacts after a year or so.

Edited By Dave Halford on 04/02/2021 17:12:46

David George 104/02/2021 17:29:33
1525 forum posts
472 photos

This is my reversing switch set up. When you change over the contact is released and you should only put the power back on when motor gas stopped or contacts burn out and motor may not stop.

controle switches.jpg


Emgee04/02/2021 17:42:01
1988 forum posts
250 photos


The yellow and blue wires referred to are the start winding ends coming from inside the motor, not the blue neutral from the power supply.


Keith Jenkins 104/02/2021 17:42:46
24 forum posts
4 photos

Thanks for the reply regarding pictures but I don't have anywhere to upload them to, is there anywhere that's free?

Keith Jenkins 104/02/2021 18:03:09
24 forum posts
4 photos

Hi Emgee, it was the blue and yellow wires on the board under the motor cover that I swapped not the mains supply

Edited By Keith Jenkins 1 on 04/02/2021 18:04:07

Les Jones 104/02/2021 18:04:30
2225 forum posts
153 photos

The first reply to your post has a link to the instructions to post pictures on the forum,
Just click on the bold text to take you to the information.


Keith Jenkins 104/02/2021 18:25:39
24 forum posts
4 photos

I did read about images but can't seem to create an album, I'll have another look

Thanks for all your quick responses

Emgee04/02/2021 18:37:39
1988 forum posts
250 photos


Did the motor run OK before you changed the blue and yellow cables around ?

If it did run OK then look for some broken/damaged insulation on both blue and yellow wires, if the conductor is exposed it could be shorting to earth (motor case) or the neutral conductor if that is also damaged.
Either of the above would rupture the fuse or disconnect an mcb by overload, or trip the RCCB if you have 1 fitted.


Peter Jones 2004/02/2021 19:07:27
54 forum posts

I had the same problem with lathe motor.

The original motor had two capacitors, both 'starting caps' one for forward one for reverse.

The motor I replaced it with only has single cap so needs a different reversing switch with an extra set of contacts.

You have to reverse the field windings to get motor to start in the opposite direction

At present, I haven't changed switch so only have forward rotation as it isn't possible to bridge various contacts in multi switch to obtain reverse

Emgee04/02/2021 19:26:04
1988 forum posts
250 photos


You only need to add a suitably rated DPDT switch connected into the start winding circuit to provide forward and reverse direction of the motor.


Keith Jenkins 104/02/2021 21:17:46
24 forum posts
4 photos

Thanks for the replys, I am just struggling with uploading pictures

Keith Jenkins 104/02/2021 22:10:51
24 forum posts
4 photos

Seems you have all uploaded pictures, any advice please

not done it yet04/02/2021 22:18:58
5790 forum posts
20 photos

When I started I just clicked on “albums” in the black bar at the top of the page and followed the fairly clear route. There is a faqs posting somewhere on how to do it. Searching for that may direct you to it.

Edited By not done it yet on 04/02/2021 22:19:29

Nicholas Farr04/02/2021 22:28:21
2683 forum posts
1248 photos

Hi Keith, make sure you are only uploading JPEG photos into your album and many of the special characters in the names won't work.

Regards Nick.

Keith Jenkins 104/02/2021 22:51:14
24 forum posts
4 photos

I click on albums but it says no albums found?

Nicholas Farr04/02/2021 22:57:06
2683 forum posts
1248 photos

Hi Keith, you have to create an album first. Click on albums in the green bar at the top and then click on create a photo album.

Regards Nick.

Edited By Nicholas Farr on 04/02/2021 22:59:21

Keith Jenkins 104/02/2021 23:12:55
24 forum posts
4 photos

plate.jpgswitch.jpgGot there in the end...


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