Allen Bradley Power Flex 40 Issues

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aelectricalman

aelectricalman

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Has anyone ever had this fault and what does it mean? The A/C drives are a Power Flex 40 by Allen Bradley. The fault code is F111 Enable Hardware. Could an automatic capacitor bank cause this across multiple drives? Thanks for any help.
 
F111 Enable Hardware DriveGuard Safe-Off Option (Series B) board is installed and the ENBL enable jumper has not
been removed.
Remove the ENBL enable jumper. Cycle power.
DriveGuard Safe-Off Option (Series B) board has failed.
Remove power to the drive. Replace DriveGuard Safe-Off Option (Series B) board.
Hardware Enable circuitry has failed.
Replace drive.

from the manual
 
petersonra said:
F111 Enable Hardware DriveGuard Safe-Off Option (Series B) board is installed and the ENBL enable jumper has not
been removed.
Remove the ENBL enable jumper. Cycle power.
DriveGuard Safe-Off Option (Series B) board has failed.
Remove power to the drive. Replace DriveGuard Safe-Off Option (Series B) board.
Hardware Enable circuitry has failed.
Replace drive.

from the manual
Click to expand...

Yeah, I found that, but the drive has operated for years. It doesn't explain the symptoms or why its doing what its doing. Suddenly there is a slew of them going bad.
 
if what the manual says is not helpful it is likely time to call tech support.

I did not see anything in the KB that gave any other answers, but my AB KB search skills suck.

by any chance has anything changed recently?
 
petersonra said:
if what the manual says is not helpful it is likely time to call tech support.

I did not see anything in the KB that gave any other answers, but my AB KB search skills suck.

by any chance has anything changed recently?
Click to expand...
Like updated firmware in all the drives maybe?

I imagine that anything that causes a high voltage transient on the input to the drives could be causing the same component (board B) to fail in all of them. And a poorly designed PFC bank switch could well be doing that.

Scope or monitor the power line close to the capacitor bank. You might need to add surge/transient suppression or input reactors to protect the drives.
 
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petersonra said:
if what the manual says is not helpful it is likely time to call tech support.

I did not see anything in the KB that gave any other answers, but my AB KB search skills suck.

by any chance has anything changed recently?
Click to expand...

We installed an 1800kVAr capacitor bank about 3 months ago. I don't believe it is related to the bank but I want to quickly rule out or investigate.
 
are you able to clear the fault?

how many drives do this? any commonality in when the faults occur or in the drives that fault? what size drives are having the issue?

the safe off board is powered from the drives internal 24VDC so it seems unlikely that a power line capacitor upstream could cause this kind of issue. but one never knows.
 
GoldDigger said:
Like updated firmware in all the drives maybe?

I imagine that anything that causes a high voltage transient on the input to the drives could be causing the same component (board B) to fail in all of them. And a poorly designed PFC bank switch could well be doing that.

Scope or monitor the power line close to the capacitor bank. You might need to add surge/transient suppression or input reactors to protect the drives.
Click to expand...

Are you suggesting maybe a zero voltage closing switch controller might help in lieu of to TVSS or reactors?
 
petersonra said:
are you able to clear the fault?

how many drives do this? any commonality in when the faults occur or in the drives that fault? what size drives are having the issue?

the safe off board is powered from the drives internal 24VDC so it seems unlikely that a power line capacitor upstream could cause this kind of issue. but one never knows.
Click to expand...

Yes. It has not happened for the first three months, but when it happened it happened at

2:25pm on Wednesday
2:25pm on Thrusday
2:25am on Friday

It appears to the customer that there is some sequence of a 12 hour cycle. I'm not sure at all what this has to do with anything other than just a coincidence.
 
aelectricalman said:
Yes. It has not happened for the first three months, but when it happened it happened at

2:25pm on Wednesday
2:25pm on Thrusday
2:25am on Friday

It appears to the customer that there is some sequence of a 12 hour cycle. I'm not sure at all what this has to do with anything other than just a coincidence.
Click to expand...

Does not seem like something random like a PFC system.

Is it the same drive or multiple drives?
 
Do you have the Safe Torque Off boards installed in all of the drives? If so, they are supposed to be used in safety relay circuits, so the safety circuits are going to be external wires to the drive. Given the surprising regularity of the trips, I'd start looking at the safety circuit wiring. For example maybe someone added a time clock to something and mistakenly wired it into the safety interlock system.
 
GoldDigger said:
It does sound like it might be a tap change or a PFC system that is switched in and out by POCO at particular predictable, scheduled times.
Click to expand...

I suppose it is possible but why did it start after the OP installed his PFC system?

In any case, the safe off board is powered from the internal 24VDC so I am not seeing how it gets affected by whatever is on the power line. I would think the drive would trip on something else first.

Unfortunately, we have little information to go on and the OP wants us to play 20 questions trying to dig up whatever might be going on.

Best bet is to get someone with some experience on site and look closely at what is actually going on and talk to the people there directly, and then get in touch with tech support once there is some certainty that he knows what is really happening.

Maybe install some power monitoring equipment first and see if there is some disturbance on the power lines.

I am curious how they know the exact time the drives tripped. Are the trips monitored by some kind of SCADA system so we know that is the actual time or are we relying on someone's memory?

It would help to know a lot more about the actual application, the plant they are installed in, and a lot of other things like whether the drives were even running at the time the trips occurred.

if there is a SCADA involved, a printout of the alarm and information logs for a few days on either side of these alarms might give us some clues. it is quite possible there are other trips that happen at this time on a regular basis as well that we don't know about.

if this just started recently, and there is some belief that it is power line related, a chat with someone at the POCO might be in order. They may well have records of what was going on at those times that could be helpful.
 
GoldDigger said:
Like updated firmware in all the drives maybe?

I imagine that anything that causes a high voltage transient on the input to the drives could be causing the same component (board B) to fail in all of them. And a poorly designed PFC bank switch could well be doing that.

Scope or monitor the power line close to the capacitor bank. You might need to add surge/transient suppression or input reactors to protect the drives.
Click to expand...

Golddigger,
Of all the comments posted, yours seem to be the most on the mark.
We recently investigated an incident that caused (37) 48VDC rectifier modules (200A, 480VAC 3-phase input) to be damaged simultaneously by a faulted Power Factor Correction Capacitor Bank (PFCCB) on the POCO 12KV line feeding this phone company central office. Ironically we met up with a power tech from another phone building in the area while having coffee who reported that he was having problems with all of the motor drives in his building that same morning. Something about having to reprogram them all.
For more details, I have attached a condensed version of the 4 page field service report we provided to the customer.
 

Attachments

  • 13075 FSR Condensed.doc
    32 KB · Views: 5
ATSman said:
I suggest that the OP disconnect the PFCCB in the process of elimination.
Click to expand...


We have run into at least 30 other situations where cutomer's cap banks were the direct cause of other equipment malfunctions.

Our "smart customers" will now turn off their caps if they have to run a critical process or meet production quotas for that month.

What they save in some cases on their utility bills demand penalty reduction is much less then their lost production costs etc.
 
ghostbuster said:
We have run into at least 30 other situations where cutomer's cap banks were the direct cause of other equipment malfunctions.

Our "smart customers" will now turn off their caps if they have to run a critical process or meet production quotas for that month.

What they save in some cases on their utility bills demand penalty reduction is much less then their lost production costs etc.
Click to expand...

sounds like someone should write a paper on this. if one PE has 30 documented cases where these kind of cap banks are creating havoc, that suggests it is a widespread issue.

OTOH, these kind of cap banks are pretty common so one would think this problem would be well known.

I have never been a big fan of this style of PFC. I like the idea of putting them at the motor. However, that introduces the potential for circulating currents between the the PFC caps and nearby VFDs that is avoided by having the PFC on the utility side.

It might be that the real problem is the PFC is improperly controlled or does not have sufficient granularity, possibly in an attempt to reduce costs. It suggests to me that if one decides to get a utility side PFC system that maybe some external monitoring of how it is operating and the potential effects on power quality are included, and that the vendor of the PFC system should not be involved in providing that monitoring.
 
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petersonra said:
sounds like someone should write a paper on this. if one PE has 30 documented cases where these kind of cap banks are creating havoc, that suggests it is a widespread issue.

OTOH, these kind of cap banks are pretty common so one would think this problem would be well known.

I have never been a big fan of this style of PFC. I like the idea of putting them at the motor. However, that introduces the potential for circulating currents between the the PFC caps and nearby VFDs that is avoided by having the PFC on the utility side.

It might be that the real problem is the PFC is improperly controlled or does not have sufficient granularity, possibly in an attempt to reduce costs. It suggests to me that if one decides to get a utility side PFC system that maybe some external monitoring of how it is operating and the potential effects on power quality are included, and that the vendor of the PFC system should not be involved in providing that monitoring.
Click to expand...

Bob,
Did you read the attached report I sent earlier?
 
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