Powerflex 700 Aux Input Fault

[Electromatic]

I have a drive for a 140HP pump motor that stopped working this past weekend. The drive is within an AB factory-assembled cabinet. When you try to start it (for testing: via HAND on the selector switch), it immediately stops with an F2 AUXILIARY INPUT FAULT. Digital IN5 is setup up with the Aux Fault parameter. I DO have voltage on that input when trying to start.
Looking at AB wiring examples, that seems correct: I want a voltage/input/(1) on that channel for normal operation. I don't understand why it's registering as a fault.
On a side note: Can anyone confirm if it's usual for this input to be used as shown in the attached diagrams (basically running through a phase loss relay and a couple of thermostats)? I usually think of AUXILIARY as equipment outside of the drive/motor starter.
Thanks.

 

[Teaser2]

Transformer thermostat and bridge thermostat are in series; sometimes they are used for temperature monitoring? Schematics shows EA13, terminal 2 and 3, N.O. is used and the note says set time to 2 seconds. I take that as timer relay to give you a delay for your fault?
Also, double check to see what parameter 365 is set to. it says 365=3. I do not have the manual available at the moment for Power Flex 700.

 

[Jraef]

Because this is an 18 pulse drive, they need to monitor the transformer and bridge rectifier heat sink temperature, because those are EXTERNAL to the actual drive itself. Using Input 5 was standard for the 18 pulse PF700 designs.

Then they also put that in series with the phase monitor relay (not standard, so someone asked for that), so one of those 3 things is likely tripping, but it's going to take some sleuthing to figure out which one. Jump them out one at a time and run it briefly to see which one was tripped, then figure out why.

My money is on the transformer thermostat. 15 years old, the transformer might be getting dirty and not cooling as well as it used to.

 

[Electromatic]

It turns out the control power--including the drive input--is routed through a UPS to allow automatic restarting on power loss. We called in some outside help, and with an oscilloscope found the UPS was dropping its output voltage for one cycle(Hz) on a run command.

 

[Jraef]

It turns out the control power--including the drive input--is routed through a UPS to allow automatic restarting on power loss. We called in some outside help, and with an oscilloscope found the UPS was dropping its output voltage for one cycle(Hz) on a run command.

Ouch!

 

[Syed Kazmi]

Hello everyone,

My VFD PowerFlex 70 is not powering up, but I am trying to repair it. Removed the blown IGBT and applying the DC voltage on Bus. But still VFD is not powering up. anyone can help?
Pre-charge circuit is good.

 

[Jraef]

Hello everyone,

My VFD PowerFlex 70 is not powering up, but I am trying to repair it. Removed the blown IGBT and applying the DC voltage on Bus. But still VFD is not powering up. anyone can help?
Pre-charge circuit is good.

You really shouldn’t tag into another post, but in general, a blown IGBT is usually the final straw in a series of cascading failures. So it’s likely that something else was critically damaged first, or at the same time. If you have DC on the bus, but the drive is not powering up, most likely the power supply board that feeds the control boards was damaged by the same thing that took out the IGBT. You can try replacing that too, but be aware that it too may not be the only thing.