Startup For 4195Kb And Kc Series Controllers; Calibration Of 4195Kb And Kc Series Controllers - Emerson Fisher KC Series Instruction Manual

4195KA, KB, KC, and KS Controllers
Startup for 4195KB and KC Series
Controllers
Perform the prestartup checks and, if necessary,
calibrate the controller prior to this procedure.
When performing the startup
procedures, keep in mind that the
initial settings are guidelines. They
will vary depending on the actual
process being controlled.
1. Be sure the supply pressure regulator is
delivering the proper supply pressure to the
controller.
2. For controllers with:
Manual set point:
Move the set point indicator to the desired set point.
Remote set point:
a. See figure 2-5 for the location of the remote
set point connection. Connect an adjustable
pressure source to the remote set point
connection.
b. Adjust the pressure source until the set point
indicator reaches the desired set point.
Remember: Increasing the remote set point
pressure increases the set point.
3. Set the reset adjustment to 0.05 minutes per
repeat for fast processes. Set it to 0.5 minutes per
repeat for slow processes. For controllers with rate,
set the rate adjustment to OFF.
4. Set the proportional band to 100 percent for fast
processes. For slow processes, calculate the
proportional band percentage from the equation
below:
P.B. + 200
For example:
200
2.1 bar
5. If the controller is used in conjunction with a
control valve, return the control valve to service by
slowly opening the upstream and downstream
manual control valves in the pipeline. Close the
manual bypass valve, if one is used.
6. Tune the various controller actions.
4-4
Note
Allowable Overshoot
Pressure Span
0.14 bar
^ 13%
Tuning proportional action: Create a load upset
by momentarily changing the set point. Check for
system cycling. If the system does not cycle, lower
the proportional band setting (thus raising the gain)
and disturb the system again by changing the set
point. Continue this procedure until the system
cycles. At this point, double the proportional band
setting (proportional band setting ×2).
Tuning reset action: Disturb the system. If the
system does not cycle, speed up the reset by
changing the setting to a lower value (faster reset).
Disturb the system again. Continue this procedure
until the system cycles. When the system cycles,
multiply the reset time setting by a factor of three
(reset setting ×3) and slow down the reset by
changing the reset setting to the higher value. The
reset is now tuned.
Tuning rate action: For a controller with rate
(4195KC Series), adjust the rate toward the higher
setting until cycling occurs. When the system cycles,
divide the rate value by a factor of three (rate setting
÷3) and decrease the rate by changing the setting to
the lower value. The rate is now tuned.
7. Check the stability of the recommended
proportional band setting by introducing a
disturbance and monitoring the process.
8. Once stable control is attained, the process
pointer and set point indicator should be in line. If
they are aligned, return the set point to the desired
value. If they are not, readjust the set point to the
desired control point and proceed with step 9.
9. If the process pointer is within 5 percent of the
set point indicator, turn the link 3 adjustment (see
figure 6-13 or 6-21 for location) until the process
pointer aligns with the set point indicator. Turn the
link 3 adjustment screw clockwise to increase the
process indication or counterclockwise to decrease
it. If the process pointer is misaligned with the set
point indicator by more than 5 percent of the scale
span, perform the calibration procedures for 4195KB
and KC Series controllers.
Calibration of 4195KB and KC Series
Controllers
WARNING
To avoid personal injury or property
damage resulting from the sudden
release of pressure, do not exceed the
operating limits given in this manual.
Instruction Manual
Form 5207
April 2007