ABB ACH550-UH User Manual page 185

ACH550-UH User's Manual
Code Description
8121 REG BYPASS CTRL
Selects Regulator by-pass control. When enabled, Regulator by-pass control provides a simple control mechanism
without a PID regulator.
• Use Regulator by-pass control only in special
applications.
0 = – Disables Regulator by-pass control. The drive
NO
uses the normal PFA reference: 1106
1 = – Enables Regulator by-pass control.
YES
• The process PID regulator is bypassed.
Actual value of PID is used as the PFA reference
(input). Normally
reference.
• The drive uses the feedback signal defined by
4014 (or 4114) for the PFA frequency
FBK SEL
reference.
• The figure shows the relation between the control
signal 4014
FBK SEL
regulated motor's frequency in a three-motor
system.
Example: In the diagram below, the pumping station's
outlet flow is controlled by the measured inlet flow (A).
3
Mains 3~
3
ACH550
Inlet pipe
8122 PFA START DELAY
Sets the start delay for speed regulated motors in the system. Using the delay, the drive works as follows:
• Switches on the contactor of the speed regulated motor – connecting the motor to the ACH550 power output.
• Delays motor start for the time 8122
• Starts the speed regulated motor.
• Starts auxiliary motors. See parameter 8115 for delay.
WARNING! Motors equipped with star-delta starters require a PFA Start Delay.
• After the ACH550 relay output switches a motor on, the star-delta starter must switch to the star-connection and
then back to the delta-connection before the drive applies power.
• So, the PFA Start Delay must be longer than the time setting of the star-delta starter.
Group 81: PFA Control
Range
0, 1
2
REF SELECT
2 is used as the PFA
EXT REF
( 4114) and the speed
OR
Contactors
3
P1
P2
P3
A
Sewage
tank
0.00...10.00 s
PFA START DELAY
Resolution
1
f
OUT
f
MAX
.
P 8110
P 8109
P 8113
P 8112
f
MIN
A
A = No auxiliary motors running
B = One auxiliary motor running
C = Two auxiliary motors running
3
M
3
3~
3
P1 Outlet pipe1
M
3~
Outlet pipe2
P2
M
3~
P3 Outlet pipe3
0.01 s
.
1-181
Default
0 ( )
NO
P 4014
B C
0.50 s
Parameters
S
(%)