Masoneilan SVI3 Installation and Maintenance Manual
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© 2021 Baker Hughes Company. All rights reserved.
Table 20 outlines some effects of parameter changes.
Step Two
Run Autotune again after ensuring the:
Other Issues That Affect Autotune
Valve oscillating fast:
•
P
term too high: reduce
P
by ½ and try again
• Booster too hot (aggressive) open by-pass on booster and try again
Valve oscillation slow
-
friction:
• Increase
I
term by 20-25%
• Add
Dead Zone
– try 0.25%
Valve moves too slowly:
•
P
term too low
,
try increasing by 25%
• Stroking time set to non-zero value.
If Actuator is very large
:
Table 20: Rough Guide to Effects of Changing PID Values
Parameter
Rise Time
Overshoot
Settling Time
Increase
Value
Decrease
Value
Increase
Value
Decrease
Value
Increase
Value
Decrease
Value
P
Decrease
Increase
Increase
Decrease
Small Effect
Small Effect
I
Small Effect
Small Effect
Decrease
Increase
Decrease
Increase
D
Small Effect
Small Effect
Decrease
Increase
Decrease
Increase
• Air supply is sufficient and there are no
air leaks.
• Valve does not have excessive friction.
Add some
Dead Zone
(0.25).
•
Mounting kit components / turnbuckle/
take off rod
are not loose or in an
improper position.
• Mounting is installed correctly
.
• Alarms are cleared.
• Magnet is not out of position.
• Boosters are not too aggressive.
• Solenoid in supply line should have a Cv
that is higher than SVI3 capacity (.6).
• Is the booster by-pass valve closed?
Open by-pass valve ½ turn from closed
and Auto- tune again
