PowerFlex 525 Start/Stop question.

[tjoneill]

Hi all.

Having a problem with a PF 525 TermBlk 5 input.
I came across the drive the other day and not sure how its running.
Both the Enable, and run/fwd is hot all the time (Term 1,2), but when Input Terminal 5 is hot, the motor stops, when its not, the motor starts. That is how they are starting/stopping the motor.
Setpoints are:
P046,48 Start Source 1,2 are both DigIn TrmBlk
P047.49 Speed Reference 1,2 Drive Pot
T065 DigIn TermBlk 05 is set too 7 preset Freq.
I am going to have to change the PLC Program to start and stop from terminal 2 and jog manual from Terminal 5 but not sure how it is even running the way it is. Any input is appreciated. Thanks again.

Sorry...PowerFlex 523

 

[thefatcontroller]

It sounds like it is set to run all the time, and terminal 5 sets preset speed to zero, so stops the motor.
I cannot imagine why anyone would do that.

I suggest read the manual and check every parameter, and configure with improved start and jog controls as you say.

 

[tjoneill]

That is exactly what was going on. Finally found 1 sentence in the manual that said Terminal 5 (t065)is set to 7, then the default for F010 is 0 hz.
So someone was using a Output from the plc (controlled by a sensor) to Terminal 5, set to Preset Zero, with a speed of 0 hz.
Damn.

 

[jraef]

That is exactly what was going on. Finally found 1 sentence in the manual that said Terminal 5 (t065)is set to 7, then the default for F010 is 0 hz.
So someone was using a Output from the plc (controlled by a sensor) to Terminal 5, set to Preset Zero, with a speed of 0 hz.
Damn.

Maybe a fail safe attempt? If the PLC ever failed, the VFD would continue to run at whatever the last commanded speed was which, depending on the application, might be the desired result.