VAT Series 651 Installation, Operating, & Maintenance Instructions page 27

3.10.2.3 Setpoint ramp adjustment
Setpoint ramp effects:
• Undershoot of pressure
• Response time
Default value for S is 1. Adjustment range for S
RAMP
This parameter affects 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.
S
= •
RAMP
t P
START
P
SFS
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.
('Control View', 'Control Performance Analyzer' or
Do configuration in menu 'Setup / Control Parameter'.
VAT Vakuumventile AG, CH-9469 Haag, Switzerland
Tel +41 81 771 61 61 Fax +41 81 771 48 30 CH@vatvalve.com www.vatvalve.com
Installation, Operating & Maintenance Instructions
Series 651 DN 320-400 (I.D. 12" - 16"), Logic
t ramptime [s]
P
SFS
P
S
−
RAMP
END
P
START
P
END
Local operation:
'Service Box 2')
is from 0 to 10 s.
RAMP
With setpoint ramp optimizing
sensor full scale pressure
setpoint ramp [s]
pressure start
pressure end
Note: It's not possible to do 'Interface configuration'
t
Remote operation:
via remote operation.
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2008-02-26
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