# Powerflex 525



## electricfishery (Apr 4, 2016)

I have a powerflex 525 running a sump pump, every once in a while it faults out on 002 auxiliary input, and I have to manually reset it by pressing the Stop button. Not sure what is causing it, as it doesn't happen consistently. Was wondering if anyone else has encountered this problem.


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## JRaef (Mar 23, 2009)

There is only one thing that can make that kind of fault take place. You have something wired to an input, and that input is programmed as an Aux Fault (a setting of "12" on the programming of that input), meaning an EXTERNAL device is tripping and you want the drive to stop. Nothing else will result in an F002 fault.

It's purpose is to allow for some sort of external protection device to be wired into the drive; for example an external OL relay, a thermal sensor, a vibration monitor, flow switch, something like that. You wire it to an input of the VFD so that when it trips, you would (ostensibly) know why the drive is not running by seeing that F002 Aux fault on the drive display. 

A very common use of that feature by the way is when you have an external local disconnect switch down close to the motor. If you do, it's highly recommended that you use an Early-Break Aux Contact of the disconnect switch wired back to this input of the VFD so that if someone tries to open the disconnect under load, the Aux Fault input turns the VFD off before the main contacts of the disconnect finish opening. You do this to prevent blowing up the drive's transistors from opening the disconnect under load, because no matter how many signs you put on it telling people not to do that, they will eventually do it.

In your case, someone has apparently failed to document whatever that external device was clearly enough for you to not have to wonder what is going on. Assuming you don't have a schematic diagram, you can look at the input wiring and trace the wires back to whatever is connected to them, then figure out what that device is and why it is tripping. On a 525, there are 6 digital inputs on terminals 2, 3, 5, 6, 7 and 8. Alternatively you can look at the programming of t062, t063, 65, 66, 67 and 68 to see which one (or more) is programmed to a value of 12, “Aux Fault”. The way it works is that the input must be High all the time, so if the circuit OPENS, it triggers the fault.

Another possibility by the way is if someone is using a N.O. contact that is Held Closed when in the active state, meaning no fault, and drops out when there is a fault. The problem with doing it that way is that you can set up a little race when power is first applied as to which system acts first; if the VFD powers up faster than the external relay can close, you will get the fault. If it is set up like that, you might have to either change it or come up with a work-around. Report back if that's the case and we can walk you through that, otherwise it's overly complicated to try to describe it if you don't need to do it.


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