PowerFlex 700L - Any issues in the past with these drives

Good Morning ,

We have a bank of about 5 - PowerFlex 700L 300 hp drives.
We loose about 1 per year, sometimes one will not last 7 months. Cat # 20LD360N3NNNAN10WA Serial # MEAH9FR6. Have there been any 700L PowerFlex Drives that came out with issues
about 4+- years ago ? Rockwell says we have a dust issue , but there is very liitle dust I can see on these drives , and believe me , I have seen much much worse. I have seen drives caked in dust dust and are running 10 years.

Thanks in advance. Have a great day.

Rob,

I have not seen those drives - but some general thoughts:

How is the temperature doing?
Are the drives in a cabinet with forced air flow?

700L are liquid cooled drives, generally temperature issues are either non-existent or extremely evident. If the dust is slightly conductive however, that can be an issue. All Powerflex drives use conformal coated PC boards now, but 4 years ago that was not the case, it was optional. If they were not ordered with that option, any slightly conductive dust can wreak havoc on the board traces.

Also:
Your particular variant appears to be set up for 24VDC control and is the part number for a chassis mount unit, implying that someone built it themselves into a panel. One issue I have seen with the 24VDC versions is that if whomever built the panel also used 24VDC fans and powered them from the same 24VDC PSU, a simplistic problem in the fan can drop the control voltage and take out the control board. Likewise for any other equipment powered by that same PSU that can go awry. This is ESPECIALLY true of systems built by the lowest bidder who uses the absolute cheapest junk 24VDC power supply they can buy (Meanwell... the world's worst company name. "We don't have very good QC, but we mean well.").

The VFD control board is not very forgiving, I usually dedicate a PSU just for that sole purpose, because whatever is happening on the end of a 300HP motor is usually a LOT more critical than some fans or lights.
But you didn't say what the nature of your failures is, so that's just a SWAG.

Any idea where the failure is occuring in the Drive (input (caps, rectifiers?/output/control board)? I've had issues, with power flex drives in general if not on very clean power. if it doesnt have one may want to consider line reactors and look at the cabinet /site ground.

I had a situation with a remote site that was basically on the end of a power line.. and would lose drives every couple months, tried line reactors and isolating ground, got better but kept losing drives ending up swapping out to a Danfoss VFD (FC322), and have not had a failure since in over 2 years.

Now in a similar situation, with the exact same power flex drives, in another location with very stable power. I had only lost drives from lightening damage.
(but the last time i lost one i replaced it with a danfoss).

So far my best luck with drives have been with ABB, Danfoss and Square D.

Issues I have had with Square D drives is on surges they tend to report a false ground fault error, which can only be cleared by reseting power to the drive, which is not a big deal in some situations, but at unmanned facilities such as pump stations, it requires someone to go out and reset the drive before the pump will run again.