compumotor drive burning out

[rsdoran]

Well we have Six machines but each one has 2 drives. I know I said seven but one line has a brand new machine with hydr positioning on heads. I know of 6 drives in the last few weeks and suspect a couple more from things I've heard. The machines were moved to an addition to the plant 2 years ago. The addition has newer style swithgear on the highside and the entire lines are now feed from busduct (1 duct for 2 lines).

That is changes enough, I agree with Steve first and foremost check the ambient temp and cabinet temp BUT also may want to look at grounding issues and harmonics (I state this because of new machinery installs upline). I have had some major issues recently with power problems causing motor, drive and electronic equipment failure. The facility I am in is old and has some wiring issues BUT even new/moved lines can have issues if there is a weakness in the electrical system.

If you have any recording devices you may want to monitor voltage, current, spikes, sags etc on that BUS and/or the devices. Yes look at the machines first for problems but when its a line of machines look at the source too.

When I was young I got a push from a boss (an electrical engineer that was working as a chief carnival electrician). He told me some simple things, first and foremost...ALWAYS GOTO THE SOURCE. He taught me OHMS law but I didnt realize that is what it was. The difference between silver, brown and green on plugs and how to twist the wires when connecting male/female wires. You know the simple stuff but the foundation that starts a career in an electrical field. The major one tho being ....ALWAYS GOTO THE SOURCE.

 

[Terry Woods]

Rick, Line 6 (or, there abouts) of my posting says...

"HOME" should be a position between the "TOP" Position and the Physical Limit of the Upward travel.

I also showed...


HOME = 0
TOP = W
NEAR TOP = X
NEAR BOTTOM = Y
BOTTOM = Z
GRAB LIMIT = Z + ?


Home Position is shown outside of Normal Operating positions.

..just in case your comment was directed at a possible "faux pas" on my part. (That's NOT to say that I don't produce a "faux pas" now and then... in fact, I'm sure that I produce more than my share - I think I'm starting to develop a taste for Crow!.)

Steve raises some very good, "back to basic's" questions.

I have one more...
I understand that the Drive is getting unreasonably hot. Is the motor getting hot?

From Drew...
Now when i state desired position the plc will bounce between up and down slow until the half circle plate stays on these two eyes, But it only bounces when the drive is on its way out.

It seems that the drive is losing its holding power and can't stop the motor accurately from low speed. And I think this is where the drives are destroying themselves but i'm not sure what's causing the drive to start to weaken in the first place.

Something sounds fishy here... I know that you have had these systems running for a while and they have been OK....

But... your statement about "bounce" on its way "out" (what is out? I thought we were talking up & down).

... You need to be more descriptive of your half-circle-plate and eyes. Also, need better description of how you use the two eyes. If one eye is used to count the revs... what is the other one for? How are you using it?

At what angle do these eyes sit relative to each other?

How many RPM is SLOW?

I have the feeling that the system has always been operating "on-the-edge" of a small "window". And now, something has come along to say, that is not acceptable!

So... I agree with you that we shouldn't "mask" the problem. At the same time, we should get the operating point to the mid-point of the window! That will allow for a certain amount of unexpected degredation as well as a certain amount of enhancement!

It sounds like you might be operating "on-the-edge"!

 

[antwerp]

On decel what are you doing with the current are you dumping it in to a risistor bank or are you using capacitors if you are using risistors make sure that they are wired right you might have to much resistance or your caps. might be to small
4+4=8 4*4=16 8/16=2 This is for parallel cercuit
4+4=8 this is for a series cercuit
I hope this helps
Robert

 

[Rick Densing]

Sorry about that Terry. I guess I misread your post (twice).