ABB ACS880 - Page 54

The speed reference is controlled automatically based on selected process variable.
For example, pressure, fluid level, flow, motor current.
You can pre-configure two different process control settings in the drive.
1. Each process control parameter set contains:
• Set point
• Transition dynamics
• Feedback signals selection
• PI controller settings
2. It is possible to switch between process 1, process 2 or manual mode at any
time.
In the figure below, the drive starts in manual mode following the user defined
pump speed reference. As delay time elapses, the automatic process control takes
over.
Speed reference
75.19
75.11
75.18
75.23
75.15
75.11
Speed reference
controlled by PI
controller
Time
Even if auto mode start delay is not in use, the actual automatic procedure is
activated only after the minimum production speed is reached.
In the figure below, the drive starts in manual mode following the user defined
pump speed reference. As speed reaches the minimum production speed value
defined by the user, only then the automatic process control takes over.
54 ESP program features