YOKOGAWA UT55A - Page 94

6-29
IM 05P01C31-01EN
MonitoringandControlofRegularOperations
6
Manual PID Tuning Procedure
(1) In principle, auto-tuning must be used.
(2) TunePIDparametersintheorderofP,I,andD.Adjustanumericslowlyby
observing the result, and keep notes of what the progress is.
(3) Graduallyreduce
Pfromalargervalue.WhenthePVvaluebeginstooscillate,stop
tuning and increase the value somewhat.
(4) Alsog
raduallyreduceIfromalargervalue.WhenthePVvaluebeginstooscillate(with
long period), stop tuning and increase the value somewhat.
(5) Grad
uallyincreaseDfromasmallervalue.WhenthePVvaluebeginstooscillate(with
short period), stop tuning and lower the value slightly.
ReferenceValues
forManualTuningofTemperature,Pressure,andFlowRate
Setting range
(reference)
Initialvaluefortuning(reference)
Pressure
P 100to300% 200%
I 5 to 30 s 15 s
D OFF OFF
Flow rate
P 100
to240% 150%
I 8 to 30 s 20 s
D OFF OFF
Temperature
(electric
furnace)
P 1to20% 5%
I
180 to 600 s 240 s
D 1/4 to 1/6 of I 60 s
6.4AdjustingPIDManually