West Control Solutions ProVU 4 - Manual (Page 76)

ProVU4 Controller, Profiler & Recorder/Controller - Product Manual
59407, Issue 1 – March 2008 Manual Tuning Page 75
5. Follow the instructions in the diagram below. At each stage, allow sufficient settling time
before moving on to the next stage. P.Pb is the Primary Proportional Band, Int.T is the
Integral Time Constant.
Table 26. Manually Tuning Valve Control
Time
Process Variable
T
b
Time
Process Variable
T
a
START
Apply Power to
the load.
Does the
PV
continuously
Oscillate?
Note the time
interval T
a
Set P.Pb = 0.8%
Set Int.T = T
a
Are the
Oscillations
decaying to
zero?
Multiply P.Pb
setting by 1.5
END
Note the period
of the decaying
oscillations (T
b
)
Multiply P.Pb
setting by 1.5
Set Int.T = T
b
2
No
Yes
Yes
No
The controller is now tuned.
Fine-tuning may be required
to optimise the controllers
response