PF700 Parameters reset to default

Hey guys, have any of ever seen a PF700 reset its parameters to factory default on its own while running? I don't think it is possible, but I had one the other night go back to factory defaults and the terminal setup was wrong and the drive would not run. I talked to my 2nd shift electrician who had tried to troubleshoot the problem with no luck and he said he didn't do it (he is familiar with the HIM copycat which is in the same menu area). I think the drive had faulted out for something and the operator fat fingered it to reset the drive, but of course he would deny it.

BTW, there were no thunderstorms, power flickers, or any other external power problems that night.

I've had 2 AB vfd's (PF700 & PF755) magically reset to default. Both occasions the same maintenance person was involved and both times he swears that he didn't do it.

That's what I am thinking.

Two possibilities:

1) If you are using communications, make sure that when your PLC is trying to reset a FAULT via comms, that someone has not inadvertently used the "Reset to Factory DEFAULTS" command. It's happened...

2) There is no battery backup of the RAM memory used when the drive is running, so every time you cycle power, the drive loads the user programming from the non-volatile memory into the RAM to use it, where it stays until power is cycled. On older firmware versions (not sure when), there could occasionally be a situation wherein the drive lost the ability to retrieve the programming stored in its non-volatile memory into the RAM memory after a power cycle. The fix is to update your firmware to the newest version (that will work on your hardware series), they corrected that problem a long time ago.

There was a similar situation in the first versions of 750 series drives, but for different reasons. There is so much data to store that the drive compacts it to store it (like a .ZIP file) and in the earliest versions of firmware, the compacting could occasionally go awry and skip over some parameters. They fixed that in something like Rev 1.05 (I think they are at Rev 12 now).

1. This drive is hardwired, no communications at all.

2. This is a new drive, we put it in earlier this year. So the firmware should be newer than when the problem was.

The only other time I have seen this occur was when an operator thought he was smarter than maintenance and changed the parameters. He, of course, no longer works here due to many other issues.

Mark Snodgrass said:

1. This drive is hardwired, no communications at all.

2. This is a new drive, we put it in earlier this year. So the firmware should be newer than when the problem was.

The only other time I have seen this occur was when an operator thought he was smarter than maintenance and changed the parameters. He, of course, no longer works here due to many other issues.

Click to expand...

Not an uncommon problem...

I worked on installing new crane drives at Boeing years ago when the 777 line was being built, we suspected that someone in their swing shift crane maintenance crew were screwing with the VFD programming at night. Boeing security eventually caught the guy doing it once they knew to watch. Turned out he was apparently angry that we (as a contract integrator) got the work when he was given his notice of being laid off, because until we were finished and able to turn the system over to Boeing, they had over hired (the general contractor was a year behind schedule). Had he but asked, I would have hired him as a temp, then he would have been in great shape to return to Boeing once we were done. But he screwed himself...

By the way, just because you bought it new, doesn't mean it wasn't sitting on a shelf somewhere for a long time. The current rev of firmware for PF700-VC (Vector Control) Series B is 10.003. It should say on the label, right above the UL bug, or you can use the keypad and look under the Diagnostic screens for "Device Version".

I know what you mean about stuff sitting on a shelf. I will check the firmware rev next week when I get out to the location of the drive.

Have a great weekend!!!