Replies

1. 
   none | Jul 17, 2005 05:58am | #1

   Locate the two leads going to start winding, and reverse their connections on switch assembly. Your motor should have a wiring diagram some where on it that will show how to reverse rotation. It may be on name plate or under cover for connections located on end of motor.

1. 
   Jimmbo | Jul 17, 2005 10:11pm | #4

   I can't see the wiring from the switch area because it goes behind a plate ... but I removed the cover of the starter, and it is connected with just two wires, a red and a black.  Am I correct to understand you that those are the two wires I would change?  Then it starts and runs the other way?

   If that's it, I'll try it.  Thanks -

1. 
   none | Jul 18, 2005 04:41am | #11

   First, cooling fans in motors are radial fans, meaning that they work just as well in one direction as the other. To locate start windings you will an ohmmeter or continuity checker. DISCONNECT POWER before atempting any checking. Take cover off start capicitor and short terminals together(capacitors have been known to hold a charge) Then look at the connections under power supply cover, and make a drawing to remember how the wires are connected. You say you have a red and black lead, if so take them loose from terminals. With your ohmmeter check to see if one goes to start cap. If so take both leads from start cap. Then see if other wire from start cap. shows continuity to other lead (red or black). If you have continuity from leads to start cap. and from the start cap. to leads then you have isolated the start windings. Reconnect leads to start cap (makes no difference which way), then reconnect leads to terminal board in reverse order. PUT COVER back on start cap. Then reapply power. Motor should run in reverse direction.

1. 
   philip | Jul 18, 2005 05:49am | #12

   Folks,
   Ihave two contributions to this subject:-
   1) We should not be giving all these instructions , as nobody is sure of exactly what type of motor jimbo has, or if it is suited to the intended use. I have seen many motors with all kinds of instructions, and some with none. The rule I have applied (and got away with) is "interchange the leads from within" -quote from Brooks Motors Huddersfield Britain.
   2) I think Jimbo would be better advised to go to an electrician and ask him to wire a reversing switch and check out the motor at the same time. Why a reversing switch? because it is most useful to be to reverse a lathe-for things like sanding for example.
   I am amused to see that so far nobody has warned what happens when a capacitor is discharged incorrectly i.e by human flesh.

1. 
   none | Jul 18, 2005 06:23am | #13

   I belive that I addressed the issue of discharging cap. in fourth sentance of my post! I have spent a lifetime working on motors and other things. Anything less than a complete explanation is dangerous. Why do you think that I warned to put cover back on cap. before reconnecting power? Ever see a cap.  explode? I would much rather have motor physically in my presence when describing how to check, but this isn't posssible.

2. 
   philip | Jul 18, 2005 10:00am | #14

   None,
   We are not on the same wave length- I was referring to a charged capacitor-all he has to do is make contact with the terminals on it and he gets a belt-even if the power is off.In my experience they can stay "charged" for some time-that's why I always discharge them if I am about to work on a motor.
   I have seen a capacitor burst-on a lawn mower. The gentleman was covered in white powder and got a huge fright, but otherwise was unscathed. Could have been nasty if bits had got his eyes.
   I hope Jimbo quits fooling with it , and goes the reversing switch way.

3. 
   Midnight | Jul 18, 2005 03:10pm | #15

   I have seen a capacitor burst-on a lawn mower.

   och... until ye've dealt wi the aftermath of 120 of the things blowing in quick succession ya hinna lived...!!  Ahem... never seen so much bits o foil n green sludge in my life.!!!

   wasn't my wiring... honest Guv...Mike Wallace

   Stay safe....Have fun

2. 
   dukeone | Jul 17, 2005 06:42am | #2

   Reversibility is stated on the nameplate. Actually the name plate is much more then a informal sticker on the side of the motor. If you go through the N.E.C. motor section many rules are based on what the nameplate says.  One factor in weather a motor is reversible is how the leads are bought out to the connection box. You can hook it up to a d.p.d.t. switch with an off stop(best type of switch; it makes you stop in the off position before changing direction). The whole deal is based on the fact that no single phase motor is self-starting. They all need some sort of setup  to get it going unlike 3 phase motors. By reversing the magnetic direction of the starting winding (swapping the wires to that winding) you give it a push in either direction. Once apon a time there were several types of single phase motors with neat gizmos to get them going but they are museum pieces now for the most part.

   KDM (retired Electrician)

   Kenneth Duke Masters
   The Bill of Rights
   December 15 1791
   NRA Endowment Member
   LEAA Life Member
   CRPA Member
1. 
   Jimmbo | Jul 17, 2005 10:08pm | #3

   Thanks for lending your expertise.  I checked the nameplate, but nothing there seems to relate to direction of turning, or whether it is reversible.  If I understand you correctling, the direction is a question of the start ...?  There is a single starter thing on the side (capicitor?) which is wired to the motor with a red and black wire.  If I swith those, will it start and run in the opposite direction?

   If you go back to "the answer is on the plate", then tell me what code I should be looking for, because I don't see any indication, but there are lettered codes that I cannot decipher.  Thanks -

1. 
   dukeone | Jul 18, 2005 03:50am | #10

   Look in the back of the cover of the motor connection box. If not there may not be reversible. The starter "thing" is the capacitor, reversing its leads won't do it. KDMKenneth Duke Masters
   The Bill of Rights
   December 15 1791
   NRA Endowment Member
   LEAA Life Member
   CRPA Member

3. 
   Midnight | Jul 17, 2005 10:30pm | #5

   be advised that changing the rotation of the motor will necessitate changing the built in fan for one with a reverse pitch...

   Mike Wallace

   Stay safe....Have fun

1. 
   Jimmbo | Jul 17, 2005 10:43pm | #6

   That makes sense.  Thanks for adding that ... it had not occured to me to othis point.  Hmm ... the job takes on complexity!

1. 
   Steinmetz | Jul 17, 2005 11:16pm | #7

   Jimbo, Buy a motor reversing switch at Macmaster Carr, and follow the directions. Or to do it on the cheap: buy a double pole double throw switch and wire it yourself. Just let the motor come to a full stop before reversing. The motors I've seen, ventilate via the fan from either end , so cooling is equal, what ever way the 'wind' blows. Steinmetz.

   Edited 7/17/2005 4:18 pm ET by steinmetz

2. 
   philip | Jul 18, 2005 12:09am | #8

   Och nae nae nae laddie-we are nae talkin boot helicorpters the noo.

1. 
   Midnight | Jul 18, 2005 01:01am | #9

   I ummmmm..... think this is the wrong forum t explain the differences between sookin n blawin...

   n fah said anythin aboot flyin food processors anyway..???????Mike Wallace

   Stay safe....Have fun

4. 
   Steinmetz | Jul 19, 2005 07:02pm | #16

   Jimbo, I*f you don't need a choice of either directions (Rh or Lh,)
   Why not Physically orient the motor end wise, so that the pulley now goes in the needed direction ? Steinmetz.

   In my first post to you, I assumed you needed to occasionally reverse directions, BUT, use forward direction as a rule?

   If you run a lathe at high speed in reverse, there's the danger of the big heavy chuck (or faceplate) flying off when the motor stops abruptly. Ed.

   
   

   ---

   Edited 7/19/2005 12:06 pm ET by steinmetz

1. 
   Jimmbo | Jul 19, 2005 10:08pm | #17

   I don't actually need the lathe to run in both directions, and so I first I considered that option of turning the motor around.  But if I leave it hanging off the left end, then it would extend the lathe bed too far to accommodate in my small shop.  If I turned the whole lathe around, putting the motor and drive spur on the right, then the motor would turn the right way, but that would make the drive spur and threading backward (must be left hand thread on the right side, like a grinder or bicycle pedal).   I also considered a second pulley configuration, so that the motor sits pulley to the right, and turns a mandrel, which in turn is connected on its left to the drive pulley ...  that would also solve the problem, but I did not want the extra bother and expense of that second set of pulleys and the mandrel.  Hence my conclusion that I must reverse the motor direction.  At least reversing the motor SEEMED easier than the other options.

   I found a FWW article on induction motor parts, and together with that, with the helpful posted responses I've received (including yours) and with any other materials I can find at the book store (books on electrical mechanics?), I plan to get into the wiring shortly and reverse the direction of current to the starter, which I understand is what is needed. 

   Of course I'll be careful to discharge the capacitor with something other than my hand ... don't want explosions ... and I'll make sure the life insurance premium is paid first!

   Thanks for the concern of those who have posted warnings ... despite my sarcasm I do appreciate it.