ABB ACQ580, Firmware Manual

Page: 65 / 422

Program features 61
Smooth pump transitions
The figure below shows the smooth pump transitions with different ramp times.
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 ( 76.55 Start delay ) is
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 (page 274 ).
3. The new pump then accelerates along IPC smooth ramp time defined with
parameter 76.62 IPC smooth acceleration time .
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.
Frequency (Hz)
Time (t)
Starting
speeds
(
40.01 )
Start
delay
(
76.55 )
Magnetizing
delay
Start level
Quick ramp 1/2
(
82 Pump pro-
tections )
IPC smooth
acceleration
time (
76.62 )
Normal ramp
Process PID output
of the current master