motor reversing switch

[dicklaxt]

A centrifical switch is some times used to drop the start winding,,,,,,,if you say there is a hum thats the thing that is gnawing on me,,who knows?

as far as the cap usage,,,,there are many combinations that are used along with aux windings that has its own capacitor,I think that is used for overload short duration ride thru,thats neither here nor there tho,just info,

dick

 

[Smart $]

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[Smart $]

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[Smart $]

... Now the push button I have on hand is a pilot duty 6 amp break with second pole added , like dicklaxt said since this is 120 v only motor , I can leave neutral connected at motor and parallel the hot through both poles on the momentary switches. That should give it a 12a break I would think . ...

Nope. Still 6A break because all the current is through the one switch (unless you have two blocks paralleled)... but it should work for a while. Not a 100% sure, but I believe that rating is for the ability of the switch to extinguish the arc on break and not degrade the contacts prematurely. The more you exceed the rating, the fewer the number of operations to failure. Also, depending on the transfer ratio and weight being hoisted, the motor may typically operate at less than the FLA rating.

 

[jap]

There's nothing wrong with using a Reversing Drum Switch.
They work find and do everything you need to do with one throw of the handle in either direction.

 

[hillbilly1]

There's nothing wrong with using a Reversing Drum Switch.
They work find and do everything you need to do with one throw of the handle in either direction.

Being a winch though, momentary would be better due to no limit switches to stop the motor from overtravel. Most drum switches are maintained contact.

 

[hillbilly1]

?...............
. Now the push button I have on hand is a pilot duty 6 amp break with second pole added , like dicklaxt said since this is 120 v only motor , I can leave neutral connected at motor and parallel the hot through both poles on the momentary switches. That should give it a 12a break I would think . The FLA on the motor is 10.4 .

You should be ok doing that (paralleling the pushbutton contacts) I know of a manufacture that does the same thing on there panel saws.

Nope. Still 6A break because all the current is through the one switch (unless you have two blocks paralleled)... but it should work for a while. Not a 100% sure, but I believe that rating is for the ability of the switch to extinguish the arc on break and not degrade the contacts prematurely. The more you exceed the rating, the fewer the number of operations to failure. Also, depending on the transfer ratio and weight being hoisted, the motor may typically operate at less than the FLA rating.

I believe he is paralleling them.

 

[jetlag]

Thanks dick

Thanks dick

A centrifical switch is some times used to drop the start winding,,,,,,,if you say there is a hum thats the thing that is gnawing on me,,who knows?

as far as the cap usage,,,,there are many combinations that are used along with aux windings that has its own capacitor,I think that is used for overload short duration ride thru,thats neither here nor there tho,just info,

dick

I wont have the hum with the controls I will use now, that was at first when I tried to use a reversing switch that only reversed the start windings and was not designed to stop the power to the run winding when the switch was in off position

 

[jetlag]

thanks smart$

thanks smart$

Nope. Still 6A break because all the current is through the one switch (unless you have two blocks paralleled)... but it should work for a while. Not a 100% sure, but I believe that rating is for the ability of the switch to extinguish the arc on break and not degrade the contacts prematurely. The more you exceed the rating, the fewer the number of operations to failure. Also, depending on the transfer ratio and weight being hoisted, the motor may typically operate at less than the FLA rating.

You missed it some how , I do have 2 switches on the same push button, paralleled with two jumpers.

 

[jetlag]

thanks jap

thanks jap

There's nothing wrong with using a Reversing Drum Switch.
They work find and do everything you need to do with one throw of the handle in either direction.

I dont like the drums because the control for this is on the end of a hanging cord to give the operator freedom to adjust cables and do other things with out running back and forth to the switch. With a drum on the pendent and operator would have to use both hands to operate , one to hold the switch and the other to hold the lever , as it would need to be a momentary spring loaded to return to off. With the push button one hand is free as you hold the box and can press the button with the thumb of the same hand.

 

[kwired]

Thanks to all replies, here is update on my plan, and it is up for suggestions, I plan to use a common 4 way 20 amp dpdt switch to reverse the start winding . I know this is not motor rated but they have been running the winch for years with the same thing in a 15 amp so it should do fine. Also the switch wont make or break because it is put in position up or down before push button power is engaged. Now the push button I have on hand is a pilot duty 6 amp break with second pole added , like dicklaxt said since this is 120 v only motor , I can leave neutral connected at motor and parallel the hot through both poles on the momentary switches. That should give it a 12a break I would think . The FLA on the motor is 10.4 . They need to get winch going right away and all we have around here is ace and lowes . I told them at the worst a switch would blow and In the meantime I have ordered some heavier switches.

The 4 way switch is only carrying the current of the start winding and not the entire load of the motor.

when someone yelled stop he paniced and hit the reverse switch , since the start windings were allready disengaged from the cut out switch , the winch keep going up.

one good reason to not have two switches unless they are momentary forward and reverse switches only - need interlocking of course so they can not operate simultaneously.

someone said in a reply that on capacitor start the start winding stay connected and only the capacitor cuts out. I dont think that is true because the capacitor is in series with the start windings so both get disconnected together. Any way this doesn't have capacitor start , only start windings with a cut out. Thats why I going back with the momentary push buttom for power in place of the snap switch.

Capacitor start will not reverse if motor is to speed - centrifugal switch cuts the entire start winding as you said, and will do same with what you have- if no capacitor it is called a "split phase" motor, is mostly same thing as capacitor start but no capacitor will not have as high of starting torque as a capacitor start will. Now a capacitor start-capacitor run motor only switches the start capacitor out of the circuit when the governor switch hits the right speed. The aux winding and run capacitor is always in the circuit. Switching the reversing switch will result in a change of direction - but it needs to decelerate to low enough speed for start capacitor to be switched back in the circuit before you will get extra torque provided by having the start capacitor in the circuit.

Being a winch though, momentary would be better due to no limit switches to stop the motor from overtravel. Most drum switches are maintained contact.

They do make momentary switches and they are used for such applications.

I dont like the drums because the control for this is on the end of a hanging cord to give the operator freedom to adjust cables and do other things with out running back and forth to the switch. With a drum on the pendent and operator would have to use both hands to operate , one to hold the switch and the other to hold the lever , as it would need to be a momentary spring loaded to return to off. With the push button one hand is free as you hold the box and can press the button with the thumb of the same hand.

Sounds like you need a pendant switch, and maybe a contactor instead of switching motor current with the light duty switch. You could still have reversing switch mounted on winch and just a momentary button on pendant to run a master contactor.

 

[Smart $]

..
I believe he is paralleling them.

You missed it some how , I do have 2 switches on the same push button, paralleled with two jumpers.

Yep, I missed it (...but give me credit for at least noting the contingency )

 

[Smart $]

...
Sounds like you need a pendant switch, and maybe a contactor instead of switching motor current with the light duty switch. You could still have reversing switch mounted on winch and just a momentary button on pendant to run a master contactor.

If going to that degree, I would just use two pushbuttons, one for up, the other for down, and two three pole relays configured accordingly. While we're at it, we could install limit switches, too. :lol:

 

[kwired]

If going to that degree, I would just use two pushbuttons, one for up, the other for down, and two three pole relays configured accordingly. While we're at it, we could install limit switches, too. :lol:

There are pendant switches that are rated for more than just pilot duty, and have either mechanical or electrical interlock capabilities, which would be the cats meow for the application, but the switch may cost just as much or more than the winch is worth. Will definitely make the four way toggle and master single pole toggle look pretty cheap.:happyyes:

 

[dicklaxt]

I found a blurb on the internet about how the start windings work on a single phase motor.Now that I have that digested and the explanation of a split phase motor with a centrificle switch as shown in the attached info Topic #5.Here's a link to that bit of info.This is the winding scenario jetlag posted up.

http://www.lmphotonics.com/single_phase_m.htm

I was able to put together a schematic using a 3PDT momentary switch spring return center off.I'm sure there are many different scenarios mentioned in the preceding posts that will work equally as well. My scanner is on the fritz,need to try and get that working this morning,I'll post a sketch later if I can get it going.

My experience with single phase motors is rare and even more rare if it is reversing as well.My involvement/design experience has always been in Refinery,Petro Chem,LNG,Plastic Plants and there was very little 1 phase unless it was included on a skid where it was then all wired ready to go by the manufacturer except for a 3 phase feeder to a control panel/j-box on skid.

dick

 

[dicklaxt]

Here's the sketch

 

[hillbilly1]

Here's the sketch

View attachment 7425

Your reversing the run winding instead of the start winding, which will still work, but the motor will still have to come to a stop before it can be reversed.

 

[dicklaxt]

Thats true on both counts,reversing the run winding is easier as you don't have to deal with the switch and the full stop will happen immediately in a boat hoist application..

dick

 

[kwired]

Thats true on both counts,reversing the run winding is easier as you don't have to deal with the switch and the full stop will happen immediately in a boat hoist application..

dick

Is just as easy to reverse either winding, you are simply changing polarity in either case, and all that is required for reversing the motor is a change in polarity relationship between the two windings.

The hoist will stop rather quickly, but may still possible to switch from forward to reverse before it slows enough to open the centrifugal switch - if that happens it will not reverse rotation.

 

[Smart $]

...and the full stop will happen immediately in a boat hoist application..

...The hoist will stop rather quickly, but may still possible to switch from forward to reverse before it slows enough to open the centrifugal switch - if that happens it will not reverse rotation.

I agree. If switched between forward and reverse before the speed switch kicks in, the motor will likely continue to run in the same, but-now-wrong direction.