Emerson 818-9010, Installation And Operation Manual

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8 Valve
Calibration
Feature
The calibration mode feature allows the user to set a
time schedule to calibrate the HPV and/or BGV fully open
100 % or 0% closed to keep valve position accuracy
during long period runtime. The calibration mode feature
also has a monitoring parameter set by user to track when
to initiate calibration if valve position is within a percent-
age range to reduce system disruption.
In calibration mode, the High Pressure CO2 control-
ler will send a signal of 100% to the XEV20D drive and a
10 volt analog output to calibrate open or a 0% to the
XEV20D drive and a 0 volt analog output to either of the
HPV and/or BGV. There is also a status display on both
the Visograph and E2 to show if the calibration mode is
initiated.
There are two parameters that will enable the valve
calibration mode feature. The calibration parameters are:
1. Cal Time - is the hour of day the calibration mode
will be initiated.
2. Cal Day - is the interval days of when the calibration
mode will be initiated.
3. Cal T Frame - is the time period to monitor and wait
for when the PID sets the valve percentage equal to or
exceed the Cal Min Valve % before initiating calibration
mode to minimized system disruption.
4. Cal Min Valve % - is the value for when the valve
percentage has to equal to or exceed before executing cali-
bration mode IF Cal T Frame value is greater than 0.
5. Direct - is the direction the calibration mode will be
initialize the valve fully open or closed.
Cal Time and Cal Day values have to be greater than 0
to enable calibration mode.
Examples:
Table 8-1 - Cal Time and Day Values
HPV Cal Time 22
HPV Cal T Frame 1
HPV Cal Min Valve % 20
HPV Direct Closed
For my HPV valve, the calibration mode will take
place every day because HPV CAL Day = 1 and it will
start at 10:00PM since HPV CAL Time = 22. The calibra-
tion mode then looks at the HPV Cal T Frame and since it
is 1, the calibration mode will wait 1 hour for the valve
percentage to equal HPV CAL Min Valve % = 20 or below
to initiate the valve closed. If the valve percentage does
not equal HPV CAL Min Valve % = 20 or below in 1 hour,
then the calibration mode will initiate. If HPV CAL Min
Valve % = 0, the calibration mode will skip this parameter
and initiate every day at 10:00PM closed.
Figure 8-1
- Valve Calibration Parameters