Hi folks, been a while since I had chance to come on here but stopped up late for some advice. My son and me have got an old lathe. Not a clue what make or model, not really bothered, but it came with no motor. We got one off an old compressor which works great! Mounting bolts line up, pully for drive belt all in line but. . . . . . It turns the wrong way! It's a single phase motor, looking at the size I'd say 1 1/2 to 2 hp ish. is there any way it can be wired to run the other way?
- Thread starter Glyn
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If it is a capacitor start induction motor ( probably will be, look for a circular object clipped to the motor body - that's the capacitor ), then there will be two windings - the start winding and the run winding. So as Pete said, there will be four connections inside the motor terminal box. The start winding will have one end connected to Neutral and the other end to the capacitor. Reverse these two connections, so that current flows through this winding in the opposite direction, and the motor will then start up in reverse.
Cheers for the replies guys. Sorry for slow reply but really busy at the moment. Right, it all sounds promising! Eddie, yes it has a capacitor and your explanation sounds easy to understand! But to be sure before I try anything, I'll take a photo of the wiring and discribe what I interpret from your explanations. Piman and superls cheers for that, with eddie's explanation, I sort of understand. John, a twist in the belt isn't really an option. Stormin, it is an open belt drive machine, don't know what make or model though. In fact, I'll post some pictures because there's a lot of stuff with it that I have no idea about.Thanks again guys, I'll post the pics as soon as I get chance.
To help sort out which winding is which: the run winding has no connection to the capacitor. One end goes to Neutral and the other end goes to Live. In fact, if you don't connect the start winding or the capacitor at all, and just put mains across the run winding, an induction motor will often just sit there and hum. Then you "pull on the belt" - i.e. start it spinning, the way you want, and off it will go. Switch off, let it stop, switch on, spin it the other way - it will reverse. Apparently that's how it used to be done - no need for capacitors - before Health & Safety was invented.
Hey guys, just got back from my son's place and, following the instructions you gave me, swapped 2 wires round and IT WORKED! Motor ran the other way. . . . . . then the drive belt snapped! But a big thank you to all who gave advice. It was a dead simple job but impossible for me to do without your clear instructions. Thanks again folks. I'll get some photos on here of the lathe as soon as poss so someone can identify it and tell me what the vairous bits and pieces are for.
graffian
Seer unto the end of his beard
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The big[well 3 and 5hp] single phase motors I have had centifugal switched windings. One had a rather interesting face comutator on the armature and a small armature inside the main one, that motor was reversed by rotating the brush holder a few degrees.
