57
• Starting Procedure
6.2.3.1
Special Starting – Using DUAL Settings – Wiring Diagram
6.2.4
Choosing a Suitable Pump Curve (Centrifugal Pumps)
6.2.4.1
Starting Curve
•
Adjust Main Settings as necessary (Starter Current, Motor Current, etc.).
•
Set
Soft Starting Curve
,
Ramp UP Time
,
Current Limit
, and
Starting Voltage
to their default
values (curve 0, 10 sec., 400% and 30% respectively).
•
Start the pump while watching the pressure gauge as the pump starts and look for overshooting (“pressure surge”)
of the gauge needle above the target pressure. In case of over pressure, choose a peak torque reduction curve
(Soft Start Curve 1!!).
•
Set
Soft Start Curve
1!!,
increase
Ramp UP Time
to 15 seconds and reduce
Current Limit
to 350%.
Start the pump and watch the pressure gauge while the pump starts.
•
In most cases overshooting is reduced. If the overshoot persists, increase
Ramp UP Time
to 25 seconds (confirm
with the motor manufacturer) and try again.
•
If overpressure persists, increase the
Soft Start Curve
setting to
2!!
or
3!!
if necessary. Each increase in
the
Soft Start Curve
setting will reduce the peak torque, thus reducing the overpressure and preventing
“pressure surge” during start.
