AB PowerFlex 4 F5 Fault

What would be the main reason for getting a F5 fault on a Powerflex 4 drive. Our supply voltage is 509 VAC , P 031
Motor NP Volts is set at 460 , A 088 Max. Voltage is set at
460. As soon has I start it is faults out on F5. I know F5 is
overvoltage. Is there a parameter that I can increase like P 031 , A 088 , etc.

We have been down for 2 months and I have 4 drives all the same type fans , and all 4 want to fault out on F5. All 4 worked fine before shutdown , motors turn free , and our voltage is usally at this level. Any ideas.

Thanks in advance

Rob S.

the quick start manual says that F5 is an overvoltage fault.
Auto-reset/run type fault. Configure with parameters A092 and A093.

what is the distance you are now running to the motors? you may have to put in load filters.
something may have changed in your wiring that is causing transient voltages either on the line /load / both sides.

if you goto the ab website, you can download the manuals.

regards,
james

Thanks for the response. I have the auto restart tries to 6 ,
and then I get a F33 fault - Unsuccessful reset.

All 4 worked fine before shutdown

Click to expand...

SOMETHING changed. Input voltage, parameters, output wiring, motors? There's going to be something common to all 4.

Most of the time, when we get F5 - Over Voltage faults on our Powerflex 4, it's due to trying to slow down a motor too fast.

The problem is , it never gets started.

What if I increase P031 and A088 from 460 to about 480 or 490.

If the parameters are set the way they were before the shutdown (when they worked) then leave them alone.

You will need to identify what has changed externally. The specifications say that a 460 volt drive normal input range is up to 528 volts. The notes on 'Overvoltage' that it occurs at a DC bus voltage of 810V (equivalent to 575VAC incoming line).

Check each incoming phase to frame ground for balanced readings.

Overvoltage is a fixed protective limit on the PowerFlex 4's.

The 380-460VAC supply models shouldn't trip until the bus voltage is 810 volts, which typically doesn't happen until the main voltage is at 575 VAC (that's right out of the QuickStart manual).

You can always measure at the DC+/DC- monitoring terminals to see what voltage is really present on the bus. Parameter 226 on the PowerFlex 40's will show you what bus voltage was present at the time of fault... I'm not certain that same parameter is on the PowerFlex 4.

Are you nominally a 480V plant that runs a little high ? Could the main voltage be higher than usual because your large loads are offline coming out of shutdown ?

If the fault occurs while the drive is idle (powered up but the output is not active) then the fault is certainly due to an input power condition.

At 509VAC measured on the mains, that doesn't leave much headroom for glitches and noise spikes to reach the 528V limit. Every very fast spikes can cause the drive to fault.

The other possibility, depending on how the CE filter reacts to unbalanced power to ground voltages, can be a floating or corner-grounded input supply. Sudden shifts in the network-to-ground voltages can also cause faulting in some drives.

The solution is the same for both sources---a drive isolation transformer. You can use a single transformer to feed all four drives if they are reasonable close together. Get one with an electrostatic shield between the primary and the secondary. Also, specify one with at least 5% and preferably 5 and 10% downward taps. The secondary must be wound for 277/480V and be sure to ground the center of the wye.

The transformer will surely eliminate the faulting and will also greatly reduce the voltage and current harmonics in your power network.

I wouldn't spend too much time trying to identify with precision just what changed or what is causing the faulting. Under the conditions you describe, the transformer should be done in any case.

Thanks for all your responses and recommendations. The DC Bus is 727 VDC Ground to Phase is A 297 B 292 C 295
Phase to Phase is A-B 509 A-C 508 B-C 507

I will consider the transformer. Thanks

Similiar Problem

I didn't know if I should start a new thread or put this here. But, you can see what I decided.

We have been running 2 powerflex drives for about two years in the same application. Recently, both drives, which run simultaneously, have started to get nuisance faults for overvoltage on the weekend or when the rest of the complex is "down". It is common for these to be the only thing running.

I have pulled the common mode jumpers to "help" eliminate the possibility of picking up transiet voltages from ground currents, although it is a grounded dist sys. The sawmill however has a resistive ground and has proved troublesome when ground faults are not addressed quickly.

I believe the problem is the incoming voltage from utility.
Both sides of mill down = 530 vac phase to phase 303 vac phase to ground drive dc bus (idle) = 751 vdc


Planer Running = 500 vac phase to phase 290 vac phase to ground drive dc bus (idle) = 701vdc



Sawmill Running = 492phase to phase
285 vac phase to ground drive dc bus (idle) = 688 vdc

at 530vac and 751vdc it doesnt leave much room on the bus for regen. Braking resistor are installed and work well even with tight decel of .2 sec. We do not want to change decel.

We use line/load reactors pretty exclusively. But I am wondering if we should use isolation transformers and if they could alleviate this problem. I tend to think they would still provide high voltage to the drive if incoming power is high?

So after all this my question is will a isolation transformer help this problem or am I at the mercy of the utility comp to keep voltage regulated?

I would ask the utility to tap down your transformer. Even when your plant is loaded your voltage is still high. A 40V swing from no load to full load also suggests that your feeders are too small.

An isolation transformer won't fix your voltage swings.

Thanks for the reply allscott. We are in the process of contacting the utility now.

I have a panel with maybe 50 small drives in them controlling small conveyors. When we shut down and come back up, we typically get several F0005 faults, which can sometimes be cleared on a given drive. The typical approach here in the past has been to replace the drives.

Being relatively new here, I can see several problems. Most notably is the motor leads are THHN and are all going into a wireway before going into a conduit run to the motor itself along with 120V control circuits. With the leads removed from the drive, I've read 30V to ground in the past. Reactors were not installed in line with the drives. Could this be the source of the overvoltage fault?

From what I've read in this post, they are looking at supply voltage. The supply voltage to the drives is 490V.

The conveyors are going to be shut down a lot more often in the near future, so I'm trying to get ahead of the game.

Thanks in advance.