ABB ACQ810 - Page 242

242 Parameters
Reg bypass PID controller bypass mode.
The signal selected by parameters 28.01…28.04 is used as
the reference. The automatic starting and stopping of direct-
on-line pumps is related to this actual value instead of the
output of the PID controller.
This setting can be used in applications with a low number of
sensors and low accuracy requirements.
Example: The capacity of the pumping station (outlet flow)
follows the measured inlet flow.
2
In the diagram below, the slopes of the lines describe the
relation between the control signal (selected by parameters
28.01…28.04) and the speed of the controlled pump in a
three-motor system. At full control signal level, all pumps are
operating at maximum speed.
No. Name/Value Description FbEq
M
3~
M
3~
M
3~
3
3
3
3
3
3
Measured inlet flow = Reference for the pumping station
P3
P2
P1
P1
P2
P3
Inlet
pipe
Outlet
pipe 1
Outlet
pipe 2
Sewage
tank
Contac-
tors
3-phase
supply
Drive
Outlet
pipe 3
Control signal (%)
No aux. mo-
tors ON
Stop speed 2
Max. speed.
Start speed 2
Start speed 1
Min. speed.
Speed (rpm)
33% 66% 100%
Stop speed 1
1 aux. motor
ON
2 aux. mo-
tors ON