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DC Drive pulses enabled bit goes false?

Created by: Timmy at: 11/20/2012 12:51 AM (5 Replies)

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11/20/2012 12:51 AM	Rate (0)
Timmy Posts: 41 Rating: (0)	I have installed a 6RA80, 2000 AMP unit on a 1000 amp dc motor. I have had some issues with the drive but have been able to work through all of them except one. After running for (3 days the first time and 4 days the second) the drive begins to behave erratically. When the stand is hit with a load (billet) the RPM drops considerably and the drive does nothing to recover. The pulses enabled bit goes false in the status word but no other bits change state and it just sits there still drawing armature current until the load clears and then it recovers. I have attached an IBA photo of one of the examples. This example has a load that is near 100% of the motor rated current, but in the other instances it is as low as 70% and still doing the same thing. The current limit is set to92% of the driverated 2000 amps and it doesn't come close to thatvalue. The I2tcurrent limiting was disabled after the first running just to make surethat for some odd reason it was doing it and the RPM speed current limiting was also disabled. The RPM acutal vs setpoint faultwas also disabledduring commissioning for process reasons so it also isout of the picture. I don't get any alarms from the drive and the drive doesn'tfault out. It just runs like this until the process can no longer take it and they move the stand to another motor and run without it. I have checked the manual to try to back track from the pulses enabled bit but the generation of that signal is not documentedexpect for little bit of information in the operational flow chart.I have a call into siemens but they are still looking into it themselves. I am wondering what else to look at? Does anyone have any additional information about the pulses enabled bit generation so I may be able to use that as a clue and back track from there? Could this be a firmware or software issue? At this point I will take any and all ideas. Attached you will find a picture depicting what is going on. Let me know if there is any additional information that you will need. Thanks. Attachment Drive_Pulses_Enabled_False_11_19_12com.JPG (332 Downloads)
Timmy Posts: 41 Rating: (0)
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11/20/2012 6:43 AM	Rate (0)
PISCEAN 2010 Diamond Member Joined: 4/23/2010 Last visit: 11/23/2024 Posts: 8092 Rating: (880)	Timmy .... The RPM acutal vs setpoint faultwas also disabledduring commissioning for process reasons so it also isout of the picture. I don't get any alarms from the drive and the drive doesn'tfault out..... Thanks. I think that is why drive is not giving any alarm or fault even the speed drops & keeps on running.

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11/21/2012 7:52 AM	Rate (0)
KSN Platinum Member Joined: 8/25/2006 Last visit: 1/15/2025 Posts: 2211 Rating: (280)	Hello. Is yourthreadabout the same problem or not? Check also torque and alpha limits when hitting the billet.

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11/21/2012 5:48 PM	Rate (0)
Timmy Posts: 41 Rating: (0)	KSN, Yes it is the same drive and I apologize I should have just added onto the existing thread (moderator help please). I have looked at the torque limits and they are no where in the picture. Some colleagues have brought up the line voltage and dips, but again no alarms so it is not dropping by that much. This then leads me to the alpha limits. Currently at 30 how far would you take this down? 25? 20? The largest value I can keep in the parameter p50150 to solve the problem I suppose....but any rules of thumb or experience based considerations would be most appreciated. Thanks.
Timmy Posts: 41 Rating: (0)
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11/22/2012 12:26 PM	Rate (0)
KSN Platinum Member Joined: 8/25/2006 Last visit: 1/15/2025 Posts: 2211 Rating: (280)	Check all limit bits (torque, current, alpha) in r53190 while billet hitting.

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10/16/2024 1:50 AM	Rate (0)
AutoGen_3543126 Member Joined: 8/8/2022 Last visit: 11/6/2024 Posts: 1 Rating: (0)	I AM FACING SAME ISSUE SPEED DROP WHILE LOAD BIT THE STAND ANY SOLUTION MY DRIVE IS 2Q

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