VAT 653 Series Installation, Operating, & Maintenance Instructions page 53

Series 65
Setpoint ramp adjustment
Setpoint ramp effects: Undershoot of pressure, Response time
Adjustment range for Setpoint Ramp is from 0 to 10 s.
This parameter defines the time that is used to decrease / raise pressure between 2 setpoints. Especially
in pressure decrease situations at low flows pressure response can be improved much by adapting
setpoint ramp time.
Pressure chart
Without setpoint ramp optimizing
P
SFS
P
START
P
END
Choose the applicable formula depending on units you are familiar with.
t = Setpoint Ramp
Adjustment procedure:
1. Start with optimal gain factor and sensor delay time according to preceding tuning steps.
2. Control a typical pressure / flow situation.
3. Control a lower pressure.
4. Repeat from step 2 with longer setpoint ramps until best response is achieved.
5. Verify pressure control response for a setpoint raise situation.
Valve speed adjustment
Valve speed effects: Response time
Default value is 1.0. Adjustment range is from 0.01 to 1.0.
This parameter effects valve plate actuating speed.
Speed adjustment is effective for PRESSURE CONTROL and POSITION CONTROL.
982156EB
INSTALLATION
In case a long ramp time is required to get optimal performance for pressure
decrease situations it may be of advantage to apply different settings for decrease /
raise control situations.
Normally best pressure control response is achieved with max. valve speed. In
particular applications it may be of advantage to have a slower valve response.
OPEN and CLOSE are always done with maximum speed.
Edition 2019-06-05
With setpoint ramp optimizing
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