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Good evening you sparky lot

I'm after some wiring advice on an old single phase motor for use on a lathe. Please see the attached pics. The tails have been removed for clarity. Live was connected to terminal B, neutral to AZ. Is it possible to reverse the direction of this type of motor without having to strip it down & swap the armature round?
Many thanks in advance
Steve A

Single Phase Motor Reversing Direction IMG_20190403_194728912 - EletriciansForums.net

Single Phase Motor Reversing Direction IMG_20190403_193617398_BURST001 - EletriciansForums.net
 
Been a long time since I worked on motors, but I recall there being a box with 6(?) terminals in it. There were 2 or 3 links that could be interconnected differently across the 6 terminals which reversed the motor.

If this motor has only AZ and B, then I agree with TC.... "haven't a clue"
 
Looks like a split phase motor from the rating plate so as above you need to reverse the connections on the start winding.
 
Thanks for your prompt replies

There's no capacitor fitted to the motor. Is it right to assume the starter windings will be a smaller guage than the run windings & just swap them over wherever they terminate?
 
It does not matter whether you alter the start or the run winding - just reverse one relative to the other. This is probably as simple as swapping over the two visible fly leads on the terminal studs (there will be others on the back) and reconnecting the supply. It is not normally necessary to open the motor or interfere with the actual windings.

I would remove the two leads from the studs - probably the two ends of the run winding - and check for continuity between them. Then check for continuity between the studs, and for no continuity from the studs to the fly leads. This will prove that swapping them over will reverse one winding only, and leave the switch correctly connected.

Terminal markings are all well and good, but I find in this class of motor, a remarkable number of 'unauthorised modifications' so it is best not to assume anything and check with a meter. Also, if you have not already done so, look on the inside of the terminal box cover. You will often find a schematic or instructions.
 
It does not matter whether you alter the start or the run winding - just reverse one relative to the other. This is probably as simple as swapping over the two visible fly leads on the terminal studs (there will be others on the back) and reconnecting the supply. It is not normally necessary to open the motor or interfere with the actual windings.

I would remove the two leads from the studs - probably the two ends of the run winding - and check for continuity between them. Then check for continuity between the studs, and for no continuity from the studs to the fly leads. This will prove that swapping them over will reverse one winding only, and leave the switch correctly connected.

Terminal markings are all well and good, but I find in this class of motor, a remarkable number of 'unauthorised modifications' so it is best not to assume anything and check with a meter. Also, if you have not already done so, look on the inside of the terminal box cover. You will often find a schematic or instructions.

Was hoping he might have some pics of the terminals which would make things very simple to advise him where and how to test
 
There's one in the first post - maybe you can't view it? Only two terminals, AZ and B, each with a lead behind the paxolin and a visible flylead, hence my recommended test sequence.
 
Yes but that’s the connection for L & N.
Swapping them over will just reverse the polarity which will be seen across the whole circuit..
I thought if he could take the terminal cover off and show a picture then it would be very easy to observe if the motor is reversible and then advise what tests need to be done to ascertain which winding is which based on their respective resistances
 
I agree I don't believe swapping will make a difference. If you assume those studs are the end of a winding where are the others. That is a basic terminal connection enclosure line to one and neutral the other with other connections not readily accessible.
 
I think the terminal picture is all there is of it. The visible leads are not the supply leads, which the OP implies have been removed, I expect them to be the two ends of one winding. You can also see other leads heading towards the hidden end of the terminal studs behind the paxolin, which I expect to be the other winding. Obviously one end of the start winding is internally connected via the switch.

Many older motors were arranged like this. BTH, for example, had a terminal cover with wording on the inside to the effect of 'To reverse motor, interchange the two leads from inside the motor body'.

It is not even necessary to know which winding is the start and which the run. If you can identify the two ends of one winding by proving continuity between them, you can reverse it.
 
Sparks. Many thanks for your replies

To confirm. The supply cable has been disconnected. The two marked terminals are all that is under the cover & nothing labelled about wiring (hence this conversation)
I will remove the paxolin & hope for more terminals beneath
Thanks again
Steve
 
Might not be a good idea to do that there is likely to be some aged insulation below that which may deteriorate.
 
Don't waste time removing the paxolin until you have done the test I suggested. To recap, if after removing the two visible leads from the studs, there is continuity between the leads and also between the studs, it is merely necessary to put the leads back on the opposite studs to reverse the motor. It is usually no more complicated than that.
 
There will be a run winding with a certain resistance and a start winding with a higher resistance there may also be a centrifugal switch wired in series with the start winding. The switch opens at a certain speed to disconnect the start winding. The switch terminals may or may not be accessible.
 

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