# Motor starting in one direction



## McClary’s Electrical (Feb 21, 2009)

barnaclebill said:


> have not run into this before.
> A 1/2 hp capacitor start motor on a jet ski lift with up/down switch was not starting--only groaning. Cap is OK. Starting switch was cleaned and Motor will now only start in one direction. groans in the other. All contacts cleaned. Motor ran fine till it was not used for a year in salt air so windings are probably not an issue. Starting only in one direction is new to me and confusing.


 

A few questions need anwered for discussion.

What does "Cap ok" mean? What size cap and how did you check it? 

Is there a contactor?

"Winding are probably not an issue" is not a term used in testing. How did you determine that? 

Is the motor SP or 3p?


If this is on a lift, is there a brake on motor?

Maybe there's a mechanical backstop in the gearbox to keep from rolling back down.

More details please


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## Big John (May 23, 2010)

If it has a capacitor, it's single phase.

Without more information, I'd say check to make sure the start winding is being powered in whatever direction isn't working.

-John


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## barnaclebill (Aug 2, 2011)

mcclary's electrical said:


> A few questions need anwered for discussion.
> 
> What does "Cap ok" mean? What size cap and how did you check it?
> 
> ...


SP motor 
Capacitor checks OK even replaced it
No Brake on Motor
Checked Resistance compared to identical motor on 2nd lift
No problem with gearbox


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## barnaclebill (Aug 2, 2011)

Big John said:


> If it has a capacitor, it's single phase.
> 
> Without more information, I'd say check to make sure the start winding is being powered in whatever direction isn't working.
> 
> -John


Could start winding work in one direction and not the other?


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## Rockyd (Apr 22, 2007)

barnaclebill said:


> have not run into this before.
> A 1/2 hp capacitor start motor on a jet ski lift with up/down switch was not starting--only groaning. Cap is OK. Starting switch was cleaned and Motor will now only start in one direction. groans in the other. All contacts cleaned. Motor ran fine till it was not used for a year in salt air so windings are probably not an issue. Starting only in one direction is new to me and confusing.


Edit - I would be thinking real hard about the connections being corroded ...terminals 5 and 8 are your start windings, 1 and 4 should be run windings see what the contacts look like...



barnaclebill said:


> Could start winding work in one direction and not the other?


Edit - All things that are common to the operation of the motor run windings, start winding, capacitor should be okay, or it wouldn't run either way, *find what is not common to both directions* and check the contacts would be my first guestimate...


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## McClary’s Electrical (Feb 21, 2009)

Big John said:


> If it has a capacitor, it's single phase.
> 
> 
> -John


 
BS.............


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## Big John (May 23, 2010)

barnaclebill said:


> Could start winding work in one direction and not the other?


 Not the winding itself, but whatever switches the polarity of the winding.


mcclary's electrical said:


> BS....


 Then educate me. I've just never seen or heard of a three phase motor that needed capacitors.

-John


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## industrial951 (Jan 29, 2011)

your start winding is going to determine your direction, it sounds like your start winding isnt kicking in when reversing, dats why you here the groaning.


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## backstay (Feb 3, 2011)

Big John said:


> Not the winding itself, but whatever switches the polarity of the winding. Then educate me. I've just never seen or heard of a three phase motor that needed capacitors.
> 
> -John


You mean for other than PF correction.


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## JTMEYER (May 2, 2009)

Your centrifugal start/run switch may be stuck in run. If it will run down, but not up this is what I would suspect because the weight of the lift would help it go down, while it would have to work twice as hard to lift it. You can open the motor to chck and lube it, or sometimes you can get lucky and a good smack from a hammer will free it up.


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## CFL (Jan 28, 2009)

mcclary's electrical said:


> BS.............


Explain to me also. You know that a motor on a boat lift that has a capacitor is going to be single phase.


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## CFL (Jan 28, 2009)

backstay said:


> You mean for other than PF correction.


Who puts a capacitor on a small motor like that for PF correction?


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## Service Call (Jul 9, 2011)

Does it use a control box or a reversing switch?


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## Service Call (Jul 9, 2011)

Does it work without the belt or a load hooked to it. 

I wasn't able to edit my first post.


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## jhall.sparky (Jun 14, 2011)

barnaclebill said:


> SP motor
> Capacitor checks OK even replaced it
> No Brake on Motor
> Checked Resistance compared to identical motor on 2nd lift
> No problem with gearbox


 
replaced capacitor.....motor does start in least one direction.........hmm

replace wiring from the control to the motor. youve got a "showt" prove it by switching the direction leads and notice now the "other direction" and the switch work fine............. let me know if i eat crow!


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## jhall.sparky (Jun 14, 2011)

JTMEYER said:


> Your centrifugal start/run switch may be stuck in run. If it will run down, but not up this is what I would suspect because the weight of the lift would help it go down, while it would have to work twice as hard to lift it. You can open the motor to chck and lube it, or sometimes you can get lucky and a good smack from a hammer will free it up.


yea, yea ,he,he, whack it , come on bevis whack it, he ha ha he .........


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## jhall.sparky (Jun 14, 2011)

Big John said:


> Not the winding itself, but whatever switches the polarity of the winding. Then educate me. I've just never seen or heard of a three phase motor that needed capacitors.
> 
> -John


:stupid::tank:

which type of three phase winding _needs a capacitor_ ?_


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## kennydmeek (Sep 12, 2009)

jhall.sparky said:


> :stupid::tank:
> 
> which type of three phase winding needs a capacitor_ ?


Been many years since I was a pump man but used to take a relay and capacitor to make 3 phase Prosser pump motors run on 208 single. It was in their specs...and it worked...but did compromise horsepower. 2 1/2 got derated to 2. Dont know if Prosser still exists or not...


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## jhall.sparky (Jun 14, 2011)

kennydmeek said:


> Been many years since I was a pump man but used to take a relay and capacitor to make 3 phase Prosser pump motors run on 208 single. It was in their specs...and it worked...but did compromise horsepower. 2 1/2 got derated to 2. Dont know if Prosser still exists or not...


 
well......now were cooking with crisco!

but im kindof thinking thats a single phase with an extra winding...... i did say THINKING.


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## hardworkingstiff (Jan 22, 2007)

kennydmeek said:


> Been many years since I was a pump man but used to take a relay and capacitor to make 3 phase Prosser pump motors run on 208 single. It was in their specs...and it worked...but did compromise horsepower. 2 1/2 got derated to 2. Dont know if Prosser still exists or not...


The motor didn't need the capacitor, the lack of adequate power to feed the motor needed a capacitor to get the motor to run.

Just a little different.

I also would like to know what 3-phase motor needs a capacitor.


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## Jamuz (Aug 8, 2007)

Need a whole lot more info. AC or DC drives on this motor? Sounds to me like a problem I had with a shrink wrapping machine going into O/L on the DC drive board when trying to go up but ran down just fine. Motor was bad. NEED MORE INFO!!!!!!!!!!!!


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## JD_ (Jul 8, 2011)

Service Call said:


> Does it work without the belt or a load hooked to it.
> 
> I wasn't able to edit my first post.


Uncoupling the motor and load seems like the best step here I think.


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## JM2 (Aug 5, 2011)

A common failure in boat lifts are the drum or wafer switches that do the lead-swapping that allows a single phase cap start motor to reverse direction. These fail all the time and the leads as well, sometimes. Sounds like the run winding is kicking in but the wafer/drum switch that does the cap "direction incentive" work isn't playing like it should with the rest of the wires. Pop it open and verify that it is conductive across all it's connections. For guidance, look at the good one and, for GAWD's sake don't lose track of which lands where - or you'll have to do some research on how to hook it up the right way again. Replacing these is a bit tricky but the local boat lift service guys stock plenty of these in all the many many styles and brands needed - the wholesale houses will think you have two head and send you on a wild goose chase to find a replacement switch.
Good luck, my friend!


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## JM2 (Aug 5, 2011)

PS: These wafer/drum switches are a "gang" of spdt switches that one sets before you hit the "giddyap" button. Alternatively, some use multi-pole spdt contactors so the same thing applies - somebody isn't playing the game they were paid to do....


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## paulk2 (Nov 7, 2011)

*Check staps across switch terminals*



JM2 said:


> A common failure in boat lifts are the drum or wafer switches that do the lead-swapping that allows a single phase cap start motor to reverse direction. Good luck, my friend!


JM2 is right!

I initially suspected the cap, connections, windings, etc - then I happened to turn the switch slowly in the GOOD direction and noticed the groan - aha! the switch also controls the start winding! Turn the switch ALL the way in the good direction and it moves. Therefore, the bad direction, which only groans, must be defective because of the switch. 

Rats, now I'm going to have to spend $70 on a new switch. Wrong! One of the straps that connects two of the switch terminals had *split*. I tried soldering it but it was actually brittle and breaking apart, so I used a wire jumper. Check for a strap where the red and orange wires connect. Each one goes across two of the screw terminals.

Presto! lift goes up, lift goes down. woo hoo!

The lift is a Demco dockside lil lifter with a 1/2 hp AO smith motor and a bremas cy0178262000 up/down switch.

bremas diagram: http://www.bremasersce.com/attachme..._2011_-_cam_switches_diagrams___approvals.pdf

replacement switch

http://www.lunmarboatlifts.com/index.cfm/product/125/bremas-switch---125v240v---switch-only.cfm

demco lifts

http://www.boatliftwarehouse.com/boat_lifts/demco/

Thanks JM2!


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