# anti reverse on pump motor



## dogleg (Dec 22, 2008)

Installing a 60 hp 480volt vertical shaft pump motor today ,This pump motor has an anti reversing ratchet device on top (US MOTOR ) .Just was wondering when I go to bump it ,and the rotation is reversed could damage occur to the anti reverse mechanism?
My first thought is that it must be able to withstand the force of reverse rotation bump for an instance and the only thing would happen is that the overload could open up the circiut.
I have bumped them before with the shaft disconnected from the pump assembly but can't remember if they had anti reverse system on those particular motors.


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## Big John (May 23, 2010)

The anti-reverse is most likely only built to prevent the pump from spinning due to backflow through the pipe when electrical power is removed. It will very likely be damaged or destroyed by bumping the motor.

Motor rotation testers can be had for less than $80. I'd much rather buy that than buy the pump.


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## JRaef (Mar 23, 2009)

Yes, it will damage the ratchet if you bump it in the wrong direction, as well as likely blow fuses or trip the breaker. 

You should expect to be able to perform your bump test prior to the back spin preventer being installed or with it removed... I never remove it either, that is the mechanical contractors job. They often get lazy and don't do it, hoping the EC will so that they don't have to make another trip to the job site, but it should have been part of his contract. Be careful, as soom as you touch that device, you own it!


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## dogleg (Dec 22, 2008)

So , I use my rotation meter on the load side of the starter,How do I know that the new motor rotation will be the the same as my phase rotation meter ?I usually use my phase rotation meter when I take out an existing motor out (mark the motor leads and the feed leads) and placing the same motor back in service again.So am I missing something here with the phase rotation meter?


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## dogleg (Dec 22, 2008)

Looks like I will work with the millwright and dissassemble the anti ratcheting device before I bump it.Just seemed to me that if it came assembled that way they should at least have a warning not to check rotation until the anti reverse device has been removed.Many of you may not agree with my bump technique of simply pushing the contactor in for a second with a screwdriver .


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## John Valdes (May 17, 2007)

dogleg said:


> Looks like I will work with the millwright and dissassemble the anti ratcheting device before I bump it.Just seemed to me that if it came assembled that way they should at least have a warning not to check rotation until the anti reverse device has been removed.Many of you may not agree with my bump technique of simply pushing the contactor in for a second with a screwdriver .


When I worked for a motor shop we saw plenty vertical and hollow shaft pumps.
I can remember having them in the shop and we always tested them before they left.
I am pretty sure they removed the reverse lock mechanism before bumping and subsequently running them.

However, I do know they never hit a motor with full voltage to start it. It seemed like it was 40 -80 - 120- 230 -330 -460 volts in that order is how they started most motors.
So it is possible they did bump it?


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## dogleg (Dec 22, 2008)

As a follow up I called the tech dept. at US motors,got a guy on there that told me it was ok to bump test the motor with the anti-reverse ratchet in place as long as I don't hold it in more than 10 seconds in the wrong direction.This might be true for these motors but I will now have caution to proceed next time a millwright tells me to "bump the motor for rotation"
Thanks fo all your information and advice.


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## JRaef (Mar 23, 2009)

dogleg said:


> As a follow up I called the tech dept. at US motors,got a guy on there that told me it was ok to bump test the motor with the anti-reverse ratchet in place as long as I don't hold it in more than 10 seconds in the wrong direction.This might be true for these motors but I will now have caution to proceed next time a millwright tells me to "bump the motor for rotation"
> Thanks fo all your information and advice.


Wow, I have never heard of that. There must be some sort of dampened cetrrifugal action on the pawls of that ratchet then? The ones I have seen would engage immediately!

PS:
Looks like an instantaneous ratchet to me.
http://www.usmotors.com/TechDocs/ProFacts/Vertical-HighThrust-Features.aspx









I'd venture to say that his statement of _"...don't hold it in more than 10 seconds in the wrong direction"_ is based on the locked rotor time of the motor overload relay, not the idea of avoiding damaging anything. I wouldn't do it.


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## dogleg (Dec 22, 2008)

After I read your post I went back to the website to the initial installation manual and found it written in a caution note, just as the tech in the phillipines told me."apply power momentarily to observe the direction of rotation for which the leads are connected. Motor damage may occur if power is applied for more than 10 seconds while rotation is locked against the non -reverse ratchet." So I guess they are giving me th ok to bump it with the anti reverse "ball-o-matic" in place.


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## SteveBayshore (Apr 7, 2013)

I have worked on vertical shaft turbine pumps from 20 HP to 400 HP for years. You can bump rotation with the anti reverse ratchet in place. You can do more damage by starting it in reverse with the anti reverse mechanism disconnected, vertical shaft couplings in pump CAN UNCOUPLE. Best practice is to uncouple shaft from pump, not easy without experience on setting pump clearances.


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## SteveBayshore (Apr 7, 2013)

One more thing, be carefull, if the motor bumps in the wrong direction, the torque on the motor will make it rotate in the opposite (correct rotation) maybe one or two rotations, as soon as the power is turned off. Make sure that there are no timers in the circuit to keep the motor on!


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## Big John (May 23, 2010)

dogleg said:


> ...How do I know that the new motor rotation will be the the same as my phase rotation meter...?


 You would need a motor rotation meter, it's a separate device from a phase-rotation meter, but they are often sold in a single unit.

When connected to the windings, the rotor is manually turned, and it will indicate what terminal connections you need to get a certain direction rotation. Then you match that terminal sequence with the same sequence on your phase conductors.

As an aside, does anyone know if there is a way to check rotation with a battery while watching analog voltmeter deflection, or am I misremembering?


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## buddhakii (Jan 13, 2011)

I've never had a problem bumping them with the ratchet in place. I don't think they want us tearing apart their motor to check rotation.


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## Jlarson (Jun 28, 2009)

I love it when someone looses a lineshaft pump. We and our well company will go fishing for it for a large sum of money in return. :laughing:





Big John said:


> As an aside, does anyone know if there is a way to check rotation with a battery while watching analog voltmeter deflection, or am I misremembering?


That's for determining winding polarity if the leads aren't marked anymore.


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## micromind (Aug 11, 2007)

Jlarson said:


> That's for determining winding polarity if the leads aren't marked anymore.


Yep, winding coils need to be arranged in the proper sequence, and if the leads are not marked, you can get it right with a battery and an analog meter.


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## SteveBayshore (Apr 7, 2013)

Was called out to check on a problem with a 100 hp submersible pump a few years ago. 3/0 bugs in JB on top of well casing were pulled into the port going down the casing and stuck. Check valve had failed and pump and motor unthreaded with the backflow. After the well contractor pulled the 200' long riser pipe, the 8" diameter by about 18' long pump and motor was gently pulled up by the 200'(+-) power cables. Installation now includes external straps welded across the threaded couplings. We just rebuilt the station last year and the pump is now 200 HP.


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## frenchelectrican (Mar 15, 2007)

Jlarson said:


> I love it when someone looses a lineshaft pump. We and our well company will go fishing for it for a large sum of money in return. :laughing:
> 
> 
> 
> ...


 
Just try moi I allready went thru with that one and that did set me back 6000 Euros for that freaker thing ( the cuprit was one of my guys hook the generatour leads wrong and did not test the connection before engerized that thing on. )

The turbine section was a good 275 meter down and have to slowly pull it back up with a guide cable in choker set up with large crane to lift it up.

The antirotation cam did not work so after we get the turbine back up and got the correct verison.

That was a full day work on that.

Merci,
Marc


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