You are not registered yet. Please click here to register!


 
 
plc storereviewsdownloads
This board is for PLC Related Q&A ONLY. Please DON'T use it for advertising, etc.
 
Try our online PLC Simulator- FREE.  Click here now to try it.

New Here? Please read this important info!!!


Go Back   PLCS.net - Interactive Q & A > PLCS.net - Interactive Q & A > LIVE PLC Questions And Answers

Reply
 
Thread Tools Display Modes
Old May 18th, 2022, 09:23 AM   #16
Puddle
Member
United Kingdom

Puddle is offline
 
Join Date: Mar 2022
Location: UK - The Norf
Posts: 36
The screenshot is showing Fault code 4, which is undervoltage. Not sure if that's just been retained from the last time it powered down or if it's an active fault.

I've had a problem with Powerflex drives before where the whole panel has been turned off but the drive hasn't discharged fully and it's retained F004 on the screen, which stops it from running.
  Reply With Quote
Old May 18th, 2022, 11:05 AM   #17
Jackllx
Lifetime Supporting Member
United Kingdom

Jackllx is offline
 
Join Date: Feb 2021
Location: UK
Posts: 41
Quote:
Originally Posted by Puddle View Post
The screenshot is showing Fault code 4, which is undervoltage. Not sure if that's just been retained from the last time it powered down or if it's an active fault.

I've had a problem with Powerflex drives before where the whole panel has been turned off but the drive hasn't discharged fully and it's retained F004 on the screen, which stops it from running.
The drive thinks that it's running.



This looks like a faulty drive to me.



This being remote support is difficult, because you are relying on people telling you things, I've been caught out on this a few times, travelled to site only to find they didn't do the first thing I told them to do!
  Reply With Quote
Old May 18th, 2022, 11:19 AM   #18
iggy
Lifetime Supporting Member
United States

iggy is offline
 
iggy's Avatar
 
Join Date: May 2007
Location: FLORIDA
Posts: 194
We have had several of the 20hp PF523 do the same thing, replace the drive.
The drives were sent off to do an analysis and have not heard back yet.
__________________
I was doing some PLC Programming on my laptop while waiting on my grandmother to get ready to go out to lunch. She says she is ready, I tell her to hold on a sec I have to find a couple of bits, she reaches into her purse and pulls out a quarter for me.
  Reply With Quote
Old May 18th, 2022, 11:49 AM   #19
GaryS
Member
United States

GaryS is offline
 
GaryS's Avatar
 
Join Date: Aug 2003
Location: Lancaster Pa.
Posts: 1,767
Just a thought
I noticed before that the buss voltage was low
At the time I didn’t know what the fault 4 was
Somebody here said it was low buss voltage

It’s odd for 2 VFD’s with the exact same problem showing the exact same fault makes me wonder
Is there a line contactor in front of the VFD or a breaker inline
Check that the contactor or breaker is closing correctly (all 3 phases ) one may not be making full connection
A bad connection on one leg may cause the buss voltage to stay low the control may read it as high enough to run but too low to run correctly. I think that Power Flex drives use 2 incoming phases to power the controls if the third leg was low or missing I don’t know what would happen.
I have seen other drives run at reduced power with a single phase line input
I don’t know if they even check for incoming phase loss I know some drives don’t check or care.
And with some driver they give you the option to disable incoming phase loss fault
It think it would be worth it to check it out
  Reply With Quote
Old May 18th, 2022, 12:25 PM   #20
slp530
Member
United Kingdom

slp530 is offline
 
Join Date: Feb 2007
Location: newcastle
Posts: 42
I've had a similar fault with a low DC bus voltage, I found one of the phases going through the input line filter had failed
  Reply With Quote
Old May 18th, 2022, 03:05 PM   #21
IanM8040
Member
United States

IanM8040 is offline
 
Join Date: Sep 2021
Location: omaha
Posts: 190
The bus voltage wouldn't be low if the set voltage was 460v

460v x 1.414 gives pretty close to the output of 456v.

If it's supposed to be 480v, then I'd say it's low. but that doesn't appear to be the case if that's the setting it's at.





some testing you cold do. aside from double checking all the parameters for the motor nameplate, and ensuring those are accurate. and double checking incoming and outgoing drive voltage with a meter.

go to parameter 495 - Drive OL Mode, and set it to 0 (disabled). and then test again, see if it's automatically limiting itself due to an overload condition on ramp up. Just make sure to change it back once it's tested.
  Reply With Quote
Old May 18th, 2022, 03:12 PM   #22
IanM8040
Member
United States

IanM8040 is offline
 
Join Date: Sep 2021
Location: omaha
Posts: 190
Quote:
Originally Posted by GaryS View Post
Just a thought
I noticed before that the buss voltage was low
At the time I didn’t know what the fault 4 was
Somebody here said it was low buss voltage

It’s odd for 2 VFD’s with the exact same problem showing the exact same fault makes me wonder
Is there a line contactor in front of the VFD or a breaker inline
Check that the contactor or breaker is closing correctly (all 3 phases ) one may not be making full connection
A bad connection on one leg may cause the buss voltage to stay low the control may read it as high enough to run but too low to run correctly. I think that Power Flex drives use 2 incoming phases to power the controls if the third leg was low or missing I don’t know what would happen.
I have seen other drives run at reduced power with a single phase line input
I don’t know if they even check for incoming phase loss I know some drives don’t check or care.
And with some driver they give you the option to disable incoming phase loss fault
It think it would be worth it to check it out
it's a definitely good thing to check and ensure that the wiring is accurate.





Story time -

I was helping support over the phone a customer who had a bad PF527 drive, and they attempted to replace it. it was being run as a motion axis in the program, and was using safe torque off over ethernet, etc... all the things.

every time it was tried to run it would fault for overload. Well the first thing up was to tell them to take the U-V-W leads off and check the motor and ensure it's spinning freely (if possible), do a quick check of resistance on the motor, make sure it's not bad... I was told it was good to go, and they put it back on.

I was remote connected in and attempting everything I could to see why this was failing. nothing had changed that we knew of, and nothing programmatically changed so it made no sense at all. We even called up and double remote supported with rockwell over the phone and their guy couldn't get to the bottom of it.

Until Finally, they had another drive they wanted to try, and I said of course, go ahead and throw it in, and what do you know, over the phone I can hear ... "Hey, who hooked this up!?!? they wired it up backwards!".


for almost 2 days of support time, they had a "throw away" tech doing the hand work, while the supervisor was relaying the info for troubleshooting, and he was relaying it back through. Apparently he had hooked up the L1-L2-L3 and U-V-W backwards, and it didn't blow the drive up...It didn't even fault until you tried to run!!!!!

They swapped the leads around and it took off no problem. After being told to check the connections multiple times, and having them remove them multiple times, and not a single time did anyone realize they had wired it wrong because it powered up every time...
  Reply With Quote
Old May 23rd, 2022, 11:21 AM   #23
JankyPLC
Member
United States

JankyPLC is offline
 
Join Date: Sep 2016
Location: WI
Posts: 30
Stories like these make me think those old folks might have been onto something with a simple contactor.

Troubleshot a different drive one time faulting on OL when trying to run. Voltages, wiring etc all checked fine with drive idle... Then checked input voltage while trying to run. One phase would dip to almost nothing every time. Other two were fine. Bad contact in the MCB was creating enough resistance that under load the voltage on that phase would drop enough to (I'm guessing? cause the DC Bus voltage to dip, or overload the other two phases rectification enough to) cause the drive to fault on OL, but not enough to cause weird voltage readings with no current draw. Never forget to check that now.

As for this drive, found a new one(miracle in itself), swapped in, works perfect! In the end, original drive died, and a bad used replacement part was the diagnosis.
  Reply With Quote
Old May 23rd, 2022, 02:55 PM   #24
Nova5
Member
United States

Nova5 is offline
 
Join Date: May 2013
Location: Northern Snowball
Posts: 561
Quote:
Originally Posted by IanM8040 View Post
it's a definitely good thing to check and ensure that the wiring is accurate.


......
They swapped the leads around and it took off no problem. After being told to check the connections multiple times, and having them remove them multiple times, and not a single time did anyone realize they had wired it wrong because it powered up every time...

I had never checked nor imagined you could power it up from the output side of the VFD.
__________________
Problems that go away on their own mystically are not solved. They will return.
  Reply With Quote
Old May 23rd, 2022, 03:32 PM   #25
alan_505
Lifetime Supporting Member
Australia

alan_505 is offline
 
Join Date: Feb 2007
Location: Melbourne,Victoria,Australia
Posts: 750
Some drives will power up, some will let the magic smoke out.
  Reply With Quote
Old May 23rd, 2022, 06:48 PM   #26
ganutenator
Lifetime Supporting Member
United States

ganutenator is offline
 
ganutenator's Avatar
 
Join Date: May 2002
Location: kansas
Posts: 1,418
I know for a fact if you hook up Line voltage to the Motor leads on a Schneider drive it will make a nice boom.
I'm actually waiting for a bad drive so I can demonstrate this to the new guys at work.
  Reply With Quote
Old May 23rd, 2022, 06:50 PM   #27
ganutenator
Lifetime Supporting Member
United States

ganutenator is offline
 
ganutenator's Avatar
 
Join Date: May 2002
Location: kansas
Posts: 1,418
shout out to Ken Roach. You are the shiz dizzle.
I hope you never burn out.
Love your posts.
I haven't worked w/ AB in decades, but kinda almost wishing I was w/ your awesome support.
  Reply With Quote
Old May 23rd, 2022, 09:44 PM   #28
jraef
Member
United States

jraef is offline
 
jraef's Avatar
 
Join Date: May 2006
Location: Northern California
Posts: 2,109
Quote:
Check that the contactor or breaker is closing correctly (all 3 phases ) one may not be making full connection
A-B drives do not have phase loss detection based upon actual phase voltages, they only cares about DC bus ripple. So if a line contactor or breaker was not conducting through one phase, the VFD would not know or care until the load current increased enough to cause bus ripple.

Now if there is a LOAD contactor, i.e. a safety contactor and it is open, then the VFD would not know right away, if ever. If the drive was in SVC mode it would eventually throw a fault on "Load Loss" if programmed as such (check parameters A490 and 491 to see if it is enabled). But if it is in V/Hz mode, even with those enabled it may not know or care.

Barring that though, this sounds like a bad power module. So the thing is, TWO of them in the same installation? That sounds like maybe a problem in the motor or circuit taking out the transistors too fast for the VFD to detect it. That can happen from a phase to phase short in the windings or the motor leads. It might be high resistance enough that it doesn't show up easily when connected across-the-line, but it's enough to take out the transistors. Before hooking up a new drive, I would be doing a lot of testing on that motor with a MEGGER, not just a DMM. But also keep in mind that a basic megger test is usually just looking for phase to ground faults, you have to do a different test to find phase to phase. It's not simple.

Last edited by jraef; May 23rd, 2022 at 09:48 PM.
  Reply With Quote
Old May 23rd, 2022, 10:18 PM   #29
seth350
Member
United States

seth350 is offline
 
seth350's Avatar
 
Join Date: Jul 2011
Location: Over yonder
Posts: 373
Just sharing my experience with a 7.5HP 525.
We upgraded from PF40s and did motor/gearbox upgrade.
First power up, set the accel/decel as needed, SVC, then started.
Drive started, but motor did not move. Checked speed setpoint, it was 60Hz.
Tried again, no rotation. Checked amps, very little.
I ran autotune, tried again, the motor ran.
__________________
“Did the Lord say that machines outta take the place of livin’, and what’s the substitute for bread and beans? Do engines get rewarded for their steam?” -John Henry
  Reply With Quote
Old May 24th, 2022, 01:07 PM   #30
Nova5
Member
United States

Nova5 is offline
 
Join Date: May 2013
Location: Northern Snowball
Posts: 561
Quote:
Originally Posted by alan_505 View Post
Some drives will power up, some will let the magic smoke out.
I would fully expect the latter.
__________________
Problems that go away on their own mystically are not solved. They will return.
  Reply With Quote
Reply
Jump to Live PLC Question and Answer Forum

Bookmarks


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Topics
Thread Thread Starter Forum Replies Last Post
CompactLogix to PF525 GraemeTownsend LIVE PLC Questions And Answers 6 April 11th, 2017 11:54 PM
Motion head scratcher. moosehunter LIVE PLC Questions And Answers 13 September 14th, 2010 07:17 PM
Bubbler method to measure solution height in tanks manmeetvirdi LIVE PLC Questions And Answers 13 November 23rd, 2007 12:20 PM
AVG and AutomationDirect Head to Head zmanvortex LIVE PLC Questions And Answers 2 February 14th, 2005 08:46 AM
A Head Scratcher ndzied1 LIVE PLC Questions And Answers 24 November 9th, 2002 01:01 AM


All times are GMT -4. The time now is 11:55 PM.


.