how do you run capacitor start ac motor in reverse

[Mike_in_SD]

I have a couple of shop projects where I need to reverse a

110v capacitor start ac motor ..

whats the simplist way to do this ..

tia mike

[RBM]

If the wiring is accessible to reverse the motor, there should be a diagram on the motor or inside the splice box to show you which wires to switch

[Mike_in_SD]

rbm2(remove this)@optonline.net (RBM) wrote in :

thanks .. ill look

mike

[maradcliff]

If there is a shaft on both ends? Just use the other end. Unfortunately thats seldom an option.

[Mike_in_SD]

[e-mail] wrote in :

no .. its on my drill press

[gfretwell]

I never thought of that. Drill a hole in the wrong place and all you have to do is run the motor backward to fill it back in? ... sorry I couldn't resist

In reference to your motor, a reversable motor has 2 identical windings wound out of phase about 90 degrees. The L1 goes to the common point between them and you either hook the capacitor or line 2 to the other ends of the windings (one each) The winding that is L1/L2 is the run winding and the one that runs through the capacitor is the start. There is usually a switch in there to disconnect the capacitor when the motor gets up to speed.

There are lots of kinds of motors so you need to know what you have before you start swapping stuff around.

[mm]

Use left-handed drill bits.

People should always say why they are asking a question.

[Mike_in_SD]

oh .. I dont know .. it was a pretty simple question. I am a shop nut working on my shop more than on projects. There are potentionally lots of hacks to my equipment that could benifit from this knowledge.

I guess if you dont know the answer, you can always be funny.

or not

[mm]

Not sure I understand. Are you saying there are a lot of people who could benefit from knowing how to reverse a motor? I'm sure there are.

But people should always say why they are asking a question (unless there is a good reason not to ;-) ), because there may be more than one path to a solution, like here.

The joke's on you. I wasn't trying to be funny. Apparently you don't know about left-handed drill bits. I guess if you don't know enough to understand the answer, you can always be sarcastic.

Instead of asking me or someone if LH drill bits exist.

I'd email you in case you're stopped reading this thread or this ng by now, but you don't give your email addrss.

[mm]

Actually LH drill bits wouldn't work. My mistake.

But I think the rest of my last post was still on target, since I think your reply was based on your idea that they don't exist.

[Mike_in_SD]

Sorry mm, you dont get to make the rules.

Its like guys that cry about top posting (which you did)

I can see their argument .. but .. I can give you a counter argument that is just as valid. So sometime I top post and sometimes I bottom post.

What you are doing by wanting to know WHY .. is trying to decide if I actually NEED to reverse this motor. Think about that .. slightly insulting in itself.

And as you can see by your attempt at an answer .. the only thing that will work is ... reversing the motor

thanks to the guys that actually answered my question.

Mike

[mm]

Oh, please. You're calling it a rule. I never did. But people

*should* always say why they are asking a question, if only because they stand a better chance of getting an answer that will solve their problem, and if someone cares about other people, secondly, because it often keeps people from wasting their time giving answers that apply to the question as phrased, but don't have anything to do with what the OP is trying to do. Maybe you don't care if people here waste their time, or you think that even if it's relevant, someone will benefit from it.

Maybe someday** we'll take a survey of how many people answer questions and feel they've wasted time when the OP left out something that, had it been included, they would have given different advice.

**It would have to be a new thread. I'm sure most people have stopped reading this one.

By pointing this out, when I hadn't said a word about it, you are the one crying about top posting. So I guess you're a lot like your view of me.

Even in this one thread one can see that I normally bottom post, and most people could figure out that I top posted in this one case because I wanted to make SURE you saw my statement that LH drill bits didn't work. I wasn't addressing anything in your previous post that I hadn't already addressed in my first reply to it, which you had just read.

Well good for you. You seem like me in this regard, so why did you bring up the subject and why are you still at it? This has nothing to do with this thread or our arguing about people saying why they are asking a question.

And you take that personally? How many people post here wanting to do something when they should be doing something else? Lots. How do I know you're not one of them? I don't know.

But here is something you can take personally, and feel insulted: In this thread you've written like an insecure jackass.

I don't know that is the only thing that will work. You still haven't said what you are trying to do.

I just know the LH drill bits won't work, and that's not because of your particular situation. I reverse my drill when I use left-handed drill bits and I forgot that.

And it doesn't change what I said. People should always say why they are asking a question.

[George]

I did this when I was a kid, which is getting to be a long time ago. IIRC, you have to reverse the relative phase of the start and run windings.

My recollection is that I used a 4PDT switch; but, thinking about it now, it's not clear why. It seems like you could just leave one winding unswitched, and use a DPDT to reverse the other. Maybe I was using it for an on/off switch, too? Maybe my mind is gone.

George

[Mike_in_SD]

_g [e-mail] (George) wrote in :

I know I have used 4pdt relays on dc motors, kind of like a mechanical H bridge ... for some robot platforms I have build but .. not sure how to apply here.

somebody suggested that if I take the plate off where the main ac comes in that, there should be a diagram there to describe reverse operation. I think that may be my best bet.

thanks for the reply mike

[Mike_in_SD]

[e-mail] (mm) wrote in :

Ok mm you win

[gfretwell]

These may help

Look at the last couple pages here

[Bud--]

For the reversing function a 4-way switch - as used in lighting circuits

- could be used. Start winding to one pair of terminals, connection to rest of motor to the other pair of terminals (or whichever pair of wires shown in the motor diagram). A 4-way switch gives you straight through in one position and crossed-through in the other position.

bud--

[Mike_in_SD]

[e-mail] (Bud--) wrote in :

Thanks guys .. thats some good info

mike