32 / 76
The Operating Mode (parameter 1-1-2-3) has to be set to
Operation on frequency inverter
and the Frequency Control Type (parameter 1-1-2-5) has to be set to
Single-pump
operation
. Pump Groups (parameter 1-1-2-6) has to be set to
Pump-group control
. The
Frequency Inverter Type (parameter 1-1-2-4) has to be selected.
8.3 SVP system
SVP system
This speed-controlled system controls the pump sets in such a way that the discharge
pressure is maintained at the setpoint. Pump sets are started up and stopped when the
bandwidth limits around the setpoint are exceeded. A smaller bandwidth around the setpoint
can therefore be set.
If only one pump is running, another pump set is started up when the first pump set runs at
maximum speed and the current discharge pressure falls below the setpoint minus half the
bandwidth. The first pump set will keep running at full speed; only the newly started pump
set is speed-controlled in accordance with the setpoint. When the speed-controlled pump set
is running at minimum speed and the current discharge pressure exceeds the setpoint plus
half the bandwidth, the pump set will be stopped that has been running the longest at
maximum speed. The last pump set is stopped by the No-flow Detection function. The
Operating Mode (parameter 1-1-2-3) has to be set to
Operation on frequency inverter
and
the Frequency Control Type (parameter 1-1-2-5) has to be set to
Single-pump operation
.
Pump Groups (parameter 1-1-2-6) has to be set to
Pump-group control
. The Frequency
Inverter Type (parameter 1-1-2-4) has to be selected.
8.4 General settings
8.4.1 Setpoint, bandwidth
Setpoint, bandwidth
The pressure booster system starts up and stops the pump sets and controls the speed of
the pump sets in such a way that the discharge pressure corresponds with the configured
Setpoint (parameter 2-1-1) and is within the configured Bandwidth (parameter 2-1-2).
Pump sets are started up or stopped when the discharge pressure deviates from the
setpoint by plus or minus half the bandwidth.
8.4.2 Alternative setpoint
Alternative setpoint
An Alternative Setpoint (parameter 2-1-3) can be activated either timer-controlled or via a
digital input by configuring the Alternative Setpoint Selection (parameter 2-1-4) accordingly.
The Alternative Setpoint Start Time (parameters 2-1-5 and 2-1-6) and Alternative Setpoint
Stop Time (parameters 2-1-7 and 2-1-8) for activating the alternative setpoint have to be set
accordingly. If a digital input is to be used for activating the alternative setpoint, a digital
input has to be assigned to the alternative setpoint (one of parameters 1-3-3-1 to 1-3-3-18).
8.4.3 Additional setpoint increase
Additional setpoint
increase
For pressure booster systems operated on a frequency inverter, Additional Setpoint
Increase (parameter 2-1-9) can be used to increase the setpoint immediately before the last
pump set is stopped to fill an accumulator with a higher pressure.
8.4.4 Dynamic pressure setpoint compensation
Dynamic pressure
setpoint
compensation
To compensate any pressure losses in the piping Dynamic Pressure Setpoint Compensation
can be Enabled (parameter 2-4-7-1). The Maximum Discharge-side Pressure Deviation
(parameter 2-4-7-2) added to the setpoint is reached at Maximum System Load (parameter
1-1-4). Starting from a pump load of "zero" the current setpoint is increased quadratically
until the setpoint plus maximum discharge pressure deviation at maximum system load is
reached.
