Allen Bradley Powerflex 4 Failures

We have a number of Allen Bradley Powerflex 4 Freq. Drives in our plant. A maintenance man had powered down a panel to install some wires. When he powered the panels backup he took notice that 2 Powerflex 4 Freq. Drives did not power back up. Totally dead drives. We have had about a total of about 14 of these drives do the same thing within the last 4 years. Because of this , we have been replacing them with AC Tech drives. My question is , have any of you had close to the same problem with these drives ?

Thanks in advance,

Had the same thing happen at my plant but they were Reliance MD-60's(same thing).
Every one of them that was made before October 2005 failed at some point when the drive was powered down then back up. Found out too late that there was a return program for these defective drives. We lost more than a dozen drives.

I have seen many of these drives on ebay that have a date of mfg. before Oct. 2005 and just shake my head.

Scooter

NO not at all however I install line reactors on almost all new instalitons as I had one location with some incoming power problems and this solved the problem. I have one location in a blasting enviroment where the operator uses the drive enclosure for a storage cabinet and the drives are covered in blast meadia and still running right along with no failures in over 5 years while all the contactors beside them are replaced about every 6 mo.s due to stuff. Ive heard others talk about problems. I realy think IMO that they dont handle bad incoming power well at all.

Scooter ,

I love your "profile" picture. It looks like me when I was a kid. I was at a job fair looking for some technicians and I had this on my table and under it it said " If this was you at 5 years old , we are looking for you "

Thanks for the info , I think it is our incoming power causing alot of our problems.

It is not a power quality issue at all. You don't need to do anything about your incoming power because of this problem. You will be wasting your time and money if you try to solve this with changing your power.

It is a bad component in the drive that AB did a silent recall on. I'm pretty sure that it is long past due for them to take care of it, but you should still complain to AB.

Here is a thread where I wrote about it in 2006. Scooter is correct, it is only drives that were made before Oct 2005 as I detailed in post #19.

http://www.plctalk.net/qanda/showthread.php?t=25438&highlight=powerflex

As a side note, the AC Tech drives that I've dealt with have been a disappointment. They tend to fail at a much higher rate than the PF4 drives (minus the bad capacitor issue).

At a plant i worked at, we used to blow up about 3 or 4 drives every time we tried to run that section of the plant with the rest of the plant down. Our voltage was a little high, around 485V and also didn't have any line/load reactors. We got the power company to lower the voltage down and installed line reactors and it seemed to help.

Bruce is correct about AB's hushed recall. Some of the PF4's had a bad capacitor component (or something) and certain SNs were recalled. It's been several years ago but some of these drives may still be floating around. We had all affected drives replaced where I worked at the time. Your AB ditributor should know what recourse you may have through a warrany or lack of warranty.

Having said that, I have always had very good performance from the PF drives.

Power Flex Drives

AB did have a silent recall on these drives. I think the time limit may be up. We installed a whole line center control cabinet with 18 of these driving conveyors. after many dead units and replacements, our local AB distributor replaced them all.

I've had 2 out of 6 PF 4 drives go out on new(less than 1 yr old) die casting machinery at the company I work at. They were replaced under mfr warranty by the machine maker, but I didn't hear anything about this recall until now...interesting. I may have to go look at the mfr date on our drives, I don't think they are that old though.

Had the same thing so changed them for Mitsi, no problems since
Also we were going through PV+600 at a great rate; it seems they don't like powering down frequently (don't blame me it's an American machine & they seem to do this on many systems) so I powered the plc & HMI on a seperate supply (not through the E-stop) & put the output power through the safety & no problems since, we also have a number of other machines from the US with this kind of setup but these have Mitsi HMI's & PLC's & don't suffer the same fate.

I am still having significant failures on the PF4 and PF40 drives, fortunately I have found the BAD Capacitor and have had 100% success rate and have not seen even one of the 30-40 drive I have repaired fail. Anyone else still having problems?

We have had this problem on many of the powerflex drive and have replaced them with yaskawa (as they go bad), which in my opinion is a much more robust drive.

We have had more than 25 of the powerflex 4's go bad in my plant. Some of them were the ones that had the known problem and the rest of them are on 2 different stretchwrappers.The manufacturer installed a master control relay to kill the incoming power to the drives during an E-stop situation which i think is the wrong way to do it.(Drives don't like continuous power cycling)Our operators use the e-stop for everthing they do to the machine. We have preached and preached not to hit the e-stop unless it is an emergency.We added isolation transformer to the drives that has helped some but one day 2 summers ago on a real humid day we lost 8 drives on one of the machines.A drive would go bad and turning the power back on after replacing the drive we would here the POP of a dead short and another one would be toast, we never did figure that one out. We even sent them back to Rockwell for analysis but they couldn't find the reason for the failures.I'm in the process of replacing all future failures with the new Powerflex 525's

Rob S. said:

We have a number of Allen Bradley Powerflex 4 Freq. Drives in our plant. A maintenance man had powered down a panel to install some wires. When he powered the panels backup he took notice that 2 Powerflex 4 Freq. Drives did not power back up. Totally dead drives. We have had about a total of about 14 of these drives do the same thing within the last 4 years. Because of this , we have been replacing them with AC Tech drives. My question is , have any of you had close to the same problem with these drives ?

Thanks in advance,

Click to expand...

I have replaced these drives with brand new ones right out of
the box which did not work.

In an unrelated story, we used to have AB 1336 drives in a
panel which were never powered down for years. One day after
an extended power outage, none of these drives (10) would restart.
I used a heat gun to reheat the components in the drives, and all
of them restarted, and are still in use today.

Some info...

51276 - PowerFlex 4 and 40 drive, blank display on power up
Access Level: Everyone
Date Created: 04/15/2008 11:39 AM
Last Updated: 11/04/2013 09:04 AM

47981 - What is the expected (design) life of electrolytic capacitors in low voltage drives?
Access Level: Everyone
Date Created: 01/08/2008 12:07 PM
Last Updated: 08/21/2013 01:21 PM

18015 - Reforming AC drive capacitors
Access Level: Everyone
Date Created: 03/14/2000 10:05 AM
Last Updated: 10/03/2013 09:28 PM

Luckily, I've not had any PowerFlex 4 or 40 drives completely die on me before, but I have had a few pop their Run Fwd digital inputs. This happens if you supply a run signal to them from another 24VDC source other than the drives 24VDC supply. If when powering up, and the external 24VDC run signal is already applied to the drive, it can damage the digital input.

George