ABB ACQ580 Firmware Manual page 65

Smooth pump transitions
The figure below shows the smooth pump transitions with different ramp times.
Frequency (Hz)
Start level
Starting
speeds
(40.01)
The timing diagram of Smooth pump transitions shows the pump starting steps. In
this case, the process PID output of the current master has exceeded the start level
(76.30...76.36).
1. The IPC system starts a new pump after the start delay time
elapsed.
2. After the motor is magnetized and starts rotating, the new pump accelerates using
quick ramp 1/2 to obtain productive zone.
Note: This operation is effective only when quick ramp mode is enabled with
parameter 82.01 Quick ramp mode
3. The new pump then accelerates along IPC smooth ramp time defined with
parameter 76.62 IPC smooth acceleration
4. When a new pump is accelerating, the other pumps decelerate to maintain the
stable output of the system, shown as Normal ramp in the diagram.
5. After the new pump reaches the speed of the current master pump, the new pump
becomes the new master.
6. The new master and all the remaining pumps will start to follow the master drive
speed defined by the process PID of the master drive.
Start
Magnetizing
delay
delay
(76.55)
(page 274).
time.
Program features 61
Process PID output
of the current master
(76.55 Start
Normal ramp
IPC smooth
acceleration
time (76.62)
Quick ramp 1/2
(82 Pump pro-
tections)
Time (t)
delay) is