PaulKim1003

PowerFlex 755 F12 (HW OverCurrent)

4 posts in this topic

Hello

I have a few of powerflex 755 and a couple of them are getting F12.

We did not get this fault before and all of sudden, we are getting it.

Can anyone tell me why i am getting this fault?

Thank you :)

Share this post


Link to post
Share on other sites

If they've been in service for quite a while and are just now starting to get these faults, the real question is, what changed? If you have saved and off-line project somewhere in Drive Executive or CCW, I'd run a compare tool first to check the known good files against those on the drives. If you do not have drive tools software, use the HIM on the front of the drive and navigate to the parameters of the main control board. You will see a list that gives options like, "linear list, file groups, changed, access level". Selected changed parameters and this will show all the parameters that have been changed to something other than the default values. Write them down and compare against those in the drive that are not faulting. This will ensure that nobody has changed the parameters pcmccartney referenced above.

If this doesn't produce any meaningful results, then you want to work your way through the mechanics of the system to see if you've got an actual excess load (bad bearings, worn gear boxes, etc), loose wires anywhere in the system, excessive environmental temperatures, etc. If you have several drive that have just started doing this, it has to be something that is common to all of those drives.

Share this post


Link to post
Share on other sites

You may also want if conditions permit and you have two identical drives, one experiencing the F12 and on not, to swap their positions and their programming.  See if the problem stays with the Drive Hardware or the controlled mechanical system.  And then troubleshoot accordingly.

Share this post


Link to post
Share on other sites

F12 on a 755 is caused by 2x drive rated current outputted for longer than 8 us. It is important to know when this occurs. On start or while running. If there's and encoder installed, try running open loop. A failing encoder may cause this. Also, starting into a rotating load without flying start on. This is also caused by motor winding shorts, but probably not your case if you have many drives doing this. 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now