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Old April 9th, 2003, 10:11 AM   #1
weekev
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Rockwell Ultra servo series motors

Anyone got comments on the Control Logix Ultra Servo Motors.
We've replaced 4 already on a machine purchased 6 months ago.

Rockwell refuse to attend site without an order number and say the application must be wrong, I've had 2 independents say
it ain't. Specifically motor MPL-A310F-HK22A.

Talk locally is the Rockwell servo drives & motors just don't
provide the reliability you expect.

any/all comments appreciated
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Old April 9th, 2003, 10:26 AM   #2
kamenges
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Do all the motors have the same failure or have all four motors failed from a different cause. While we haven't used alot of this motor series and never this exact motor, we haven't had any problems with the ones we've used.

Keith
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Old April 9th, 2003, 10:36 AM   #3
weekev
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Rockwell servo motors

The most recent has been motor thermo. failure and temperature filter
alarms from the ultra drive.
Experience has shown us not to trust the drive alarms, as loose
cables etc effect what the drive "thinks" is the problem
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Old April 9th, 2003, 02:22 PM   #4
olias
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What drive are you using? Are all failures heat related? Also check your accels and decels to make sure you're not telling the motor to move faster than capable. I'm currently using the bigger drives and motors so I am curious in whats happening. Keep us posted.
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Old April 10th, 2003, 05:25 AM   #5
weekev
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Rockwell servo motors

We are using a 1398-DDM-019 drive on the motor in question.
Operator interface allows for entry of Accel & Decel setpoints
of 0-100%, but the drive itself has been setup correctly thus
accel / decel setpoints should'nt be an issue
as confirmed by 2 independent visiting engineers)

Not all faults are temperature related, and I don't believe the
faults are temperature related at all, simply that the drive is interpreting the feedback from the motor as such.

I'm told the motor in question is "new" to the range.
Perhaps my problems are specific to this motor ...
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Old April 10th, 2003, 06:41 AM   #6
rsdoran
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Quote:
Experience has shown us not to trust the drive alarms, as loose cables etc effect what the drive "thinks" is the problem
Lost me with that statement!
You cant trust the drives alarm because a loose cable effects it? A loose cable should affect it and create an alarm. Loose connections are the bane of industrial electrical devices. They can cause arcing, wiring to overheat, motors to overheat. Loose connections can burn wire that isnt visible but will derate the wires capacity.

You should definitely verify that no conditions like loose wiring exists. May help to verify the motor is rated properly for the application. Verify the parameters are properly established with the drive to match your motor.

You may want to "trust" the drive alarms a little more to isolate ANY possible issues that could create motor problems. Maybe jams, long runs at slow speeds (many motors can get too hot if run for long periods at real slow speeds with load).
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Old April 10th, 2003, 06:43 AM   #7
Steve Bailey
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Have your consultants reviewed the analysis of the load profile that these motors see?

Most servo motors carry a torque rating for continuous duty and a higher torque rating for intermittent duty. Usually this is expressed as continuous torque and peak torque. They can run all day without trouble as long as the torque remains within the continuous duty rating.

If you load them above the continuous duty rating you need to analyze the load pattern over time to make sure that the RMS torque is within the continuous duty rating. Briefly, whenever the load exceeds the continuous duty level, you need to run the motor at less than max continuous torque for some period of time to allow it to cool down.
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Old April 10th, 2003, 07:30 AM   #8
donnchadh k
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ultra drives

Hi

I work for a Cork based company in Ireland and have used the ultra 100 and 200 with different size motors and I must say I had no problems.
We have set these up on our own with a little help from tech support,and never came across anything like what you are getting.

How are you so sure that the motor was sized right first day,did you the motion cd to size it or did rockwell size them for you.

Could you give a little more detail on what load,speed and a little more info on the machine itself.


Donnchadh K.
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Old April 10th, 2003, 07:40 AM   #9
Steve Etter
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Ok. Maybe its time to look at this a little differently.

If you were to pay Rockwell to be on site, what would you be paying them for? I should imagine that they would give you, in writing, a list of what will be accomplished. If they will not, or if they do and it does not include identifying the actual problem (IMHO "your application is wrong" aint good enough), then there is no point to paying the price.

If they will agree to identify the problem, then maybe it would be worth the visit. After all, they should know their equipement and its limitiations better than anyone else. Perhaps that would be your most cost effective approach.

Just be sure to get it in writing up front.

Steve
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Old April 10th, 2003, 08:04 AM   #10
Rick Densing
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Have you measured the temp of the motors? Did you touch them? How do you know that the errors are not real?
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Old April 10th, 2003, 08:12 AM   #11
weekev
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Rockwell Motors

The latest news is that our distributor will pay for the
visit from Rockwell.
What I hoped to gain in advance were any other "scary stories"
from all you out there. This does'nt seem to be the case.

My fear was that Rockwell would/will attend site with the pre-opinion
that the equipment CANNOT be at fault , and will look for any
minor application problem and blame it.

The enviroment may be the problem , the machine is a film sealer
for food trays just before a freezer at -40c.
After production sanitation clean the machine with water at +60c.
Rockwell have never enquired about this though (all knowing I suppose)

Perhaps the application has problems (that both independent guys
could'nt see) , but the Rockwell attitide here has left me
considering another supplier.

thanks in advance for all the comments.
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Old April 10th, 2003, 12:16 PM   #12
olias
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Just checked all my references and can't find how to match an MPL series motor and a Ultra 100. I've used an Ultra 100 with a F series motor, and a Ultra 3000 with an MPL series motor. My copy of Motion Book may not be the latest. Just a thought.

Good Luck,
Olias
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Old April 16th, 2003, 10:18 AM   #13
Steve Wood
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Ultra 100 drives

I am using Ultra 100 series drives with H series motors (8 in all) and have am experiencing some problems with encoder noise on 1 axis (according to the controller fault message).

The problem seems to come and go and does not seem to be related to the amplifier or motor as I have changed them both. The problem gets more frequent the faster the motor runs. I have no problems with the other axis which have been set up in exactly the same way and all cables are shielded correctly.

If anybody has any ideas as to the cause I would be grateful.

The PLC system is an SLC504 with HSRV motion controller card.

Thanks
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Old April 16th, 2003, 10:35 AM   #14
craigsimon
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I have almost the same setup and have come up with similar problems. I am using F series motors with Ultra 100 drives and HSRV cards. One one axis, the faster we went the more the motor would fault out on encoder noise. It is only happening on one system that has four motors, four Ultra 100s, and four HSRVs. We replace the Ultra with no success. We then ran new encoder and power cable in the open, and that did nothing to the problem. We then replaced out the motor in question and it fixed that problem. As soon as that axis was fixed the same problem jumped to another axis. I am wondering if by having 4 cards in the same rack, there is a timing problem. If we slow the axis in question down, the problem goes away. I am wondering if the problem has to do with processor timing. Our other systems have only 2-3 axis and they are not having a problem. We have not resolved our problem yet.
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Old April 16th, 2003, 10:43 AM   #15
Steve Wood
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Ultra 100 problem

Sorry, I said 8 axis in all but I forgot to say they are on 4 identical machines. Each machine has 2 axis of motion but the problem you have is definately the same. I too got the problem to switch axis once by changing the motor but it did not happen when I tried it again. I am running a VERY big program so you may be correct about PLC scan timing but I would have thought it would happen on one of the other machines. I am going to fit a brand new motor in a couple of weeks so I will let you know if the problem disappears.


Thanks for your help

Steve
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