Lenze drive fireworks

hotrod

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• Dec 10, 2005

• #1

Ok, what I got is six drives lenze servo drives, it started out with one drive blowing the top contact block off of while the machine was running, so we checked the wiring and the motor but nothing showed up bad. Then we replaced the drive with another one and replaced the fuses, powered the panel up and reset the system and boom, a drive that we hadn't messed with decided to blow the bottom terminal strip cover off, once again checked everything to no avail, how could a drive be sending out voltage without an input signal?. these drives and mitsubishi plc's seem daunting to troubleshoot, I'm still wet behind the ears. thanks.

 

Pego

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• Dec 10, 2005

• #2

Have you checked the incoming power to the panel?
If you have a 3-phase with neutral, a star or wye, u can get a higher voltage to the drives if you use phase and neutral to power the drives and the neutral is not there.

 

hotrod

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• Dec 10, 2005

• #3

alright why would there be a neutral lost, I have 480 powering the panel, checked brake resistors, drives appear ok too.

 

hotrod

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• Dec 10, 2005

• #4

Anybody familiar with lamnea bruk machinery??

 

hotrod

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• Dec 10, 2005

• #5

500 ac volts incoming to panel

 

jstolaruk

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• Dec 10, 2005

• #6

I commissioned 10 AC Tech (division of Lenze) drives recently (5 drives per machine) and continue to have firmware problems that Lenze has not been supportive toward fixing. You can bet in the future this company and their products will be at the bottom of my servo drive list. I'm confident my customer is thinking the same thing.

As far as your problem, I would make sure you having proper grounding of the drive's enclosures. Use a disk sander to strip the paint off of the mounting surface of the drive enclosure and the back plate that they are bolted to. It cured some difficulties we were experiencing.

 

Last edited: Dec 10, 2005

rsdoran

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• Dec 10, 2005

• #7

If you are using a true RMS meter that you know is accurate then 500vac may be too high. I know some of the servo drives are rated 400-480 to work with European and US voltages and this does not allow you to exceed 480vac by very much, if at all. You may need to use a step down transformer to condition the voltage and maintain it around 420.

I have had issues with Lenze drives etc with high voltage.

I hate seeing an AC Tech VFD, my personal experiences with these has been ALL bad.

 

darrenj

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• Dec 10, 2005

• #8

Agree with Ron on this one.. In canada our voltage is 600v AC tech drives used to be (Dont know if they changed but i doubt it) were rated at 575v so at 600v you were already at the upper end of the voltage limit..If the voltage climed to 615-620 as it sometimes does at nights when there is less load on the grid the drives blew or tripped on high bus voltage..

 

hotrod

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• Dec 11, 2005

• #9

ok, I'll put that info to work guys, the third shift mechanic said voltage was at 490 when checked this morning, I'm going back to the trenches, thanks guys!.

 

hotrod

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• Dec 11, 2005

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ok I made sure we had good ground coming to panel and through panel, but Affraid to power up the panel, maybe have another drive blow fire out of bottom of terminal again? any suggestions, would unhooking the leads out be better?

 

jstolaruk

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• Dec 11, 2005

• #11

A short list of things we've had to do in the last six months to resolve servo issues were to put in a isolation transformer and another installation required EMI/RFI filtering. The cures were definetly to address unknowns with the plant floor environment (power and/or neighboring equipment).

 

jstolaruk

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• Dec 11, 2005

• #12

hotrod said:

ok I made sure we had good ground coming to panel and through panel, but Affraid to power up the panel, maybe have another drive blow fire out of bottom of terminal again? any suggestions, would unhooking the leads out be better?

Click to expand...

Depending on what you need, AB makes some supplemental motor protection devices that could help.

http://www.ab.com/industrialcontrols/products/supplemental_motor_protection/relays/809s.html

 

hotrod

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• Dec 11, 2005

• #13

well I'll approach my superior with that, will definetly research my application , thanks.

 

hotrod

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• Dec 11, 2005

• #14

Well that puts me in a better frame of mind.

 

hotrod

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• Dec 11, 2005

• #15

Update, I found that out of the three phases going to a motor on the machine only two of them had continuity, it was the original motor to trip the drive out,will check more in detail tomorrow, looks like a bad wire.