Despatch P1400+ Temperature Controller - Manual (Page 61)

55
6. Follow the instructions in the diagram below. At each stage, allow sufficient settling time
before moving on to the next stage.
Table 15. Manually Tuning Valve Control
Time
P
ro
c
e
s
s
V
a
ri
a
b
le
T
b
Time
P
ro
c
e
s
s
V
a
ri
a
b
le
T
a
START
Apply Power to
the load.
Does the
PV
continuously
Oscillate?
Note the time
interval T
a
Set Pb_P = 0.8%
Set ArSt = T
a
Are the
Oscillations
decaying to
zero?
Multiply Pb_P
setting by 1.5
END
Note the period
of the decaying
oscillations (T
b
)
Multiply Pb_P
setting by 1.5
Set ArSt = T
b
/2
No
Yes
Yes
No
The controller is now tuned.
Fine-tuning may be required
to optimise the controllers
response