Powerflex 525 PID Controll for a Pump in a Hot Water Set

[Dravik]

You probably want a small deadband around your pressure setpoint as well. Assuming it isn't critical to be right on the money.

 

[rupej]

+1 on the deadband, there is a parameter for that. Also, think about failure mode. If the pressure sensor fails, and thr drive sees 0mA on the input, do you want the VFD to go full speed or to stop? If you want it to stop, you may want to invert the control action, and also invert the pressure transmitter signal (many IFMs can do that). Otherwise there is a parameter in the drive to disable itself if the analog input falls below an adjustable level.

 

[travisroberts88]

+1 on the deadband, there is a parameter for that. Also, think about failure mode. If the pressure sensor fails, and thr drive sees 0mA on the input, do you want the VFD to go full speed or to stop? If you want it to stop, you may want to invert the control action, and also invert the pressure transmitter signal (many IFMs can do that). Otherwise there is a parameter in the drive to disable itself if the analog input falls below an adjustable level.

Any idea off hand what that parameter is to disable itself if the input falls below? Other than that I have it all good to go just was wanting to have that ability for if the IFM dies.

 

[Dravik]

97 for the ma signal.