Flowserve Worcester Controls Electri-SAFE DataFlo - Manual (Page 11)

FCD WCAIM2048-01 Electri-SAFE DataFlo Digital Electronic Positioner 11
Flow Control
Worcester Controls
4.4.14 Electronic Positioner Rotation Limits (Electronic travel stops)
The display will alternately display yA and its position value.
yA is the electronic lower rotation limit for shaft position at
the start of the signal range. It can be set to a value from 0.0
to 100.0 in increments of 0.1 percent.
Press the UP switch to advance to the yE parameter screen.
The display will alternately display yE and its position value.
yE is the electronic upper rotation limit for shaft position at
the end of the signal range. It can be set to a value from 0.0
to 100.0 in increments of 0.1 percent.
If yA were set at 20.0 then the actuator shaft would never
rotate further CW than 20 percent open. If yE is set to 70
percent then the actuator shaft would never rotate further
CCW than 70 percent open. These electronic limits restrict the
range of actuator shaft rotation.
yA must always be less than or equal to yE. yE must always
be greater than or equal to yA.
4.4.15 Tight Valve Shutoff
The display will alternately display yCLS and its setting.
yCLS is how we specify whether tight valve shutoff is desired
when the input signal reaches the low end of its range. It is
significant when the yA function is set to a value other than
0.0 percent. The two choices are yES and no. As an example,
if the actuator/valve is controlling fuel flow to a burner, yA
might be set to 30 percent as a low-fire position, but between
4.1 and 4.2 mA the valve would fully close if yCLS is set to
yES to allow maintenance to be performed on the burner.
4.4.16 Full-Open Operation of Valve with Open Travel Limit Set
The display will alternately display yOPn and its setting.
yOPn is how we specify whether the valve will fully open
when the input signal reaches the upper end of its range. It is
significant when the yE function is set to a value other than
100.0 percent. The two choices are yES and no. As an
example, if yE is set at 70 percent and yOPn is set to yES,
then the actuator/valve would be 70 percent open at 19.8 mA,
but would open fully when the signal is increased to 19.9 mA.
4.4.17 Restore Factory Default Values
The display will alternately display PrSt and no.
If yES is selected instead of no then the factory default values
for all parameters will be selected. This flag is not a parameter
but must be edited the same way to select yES. This is a
momentary function and values can be altered after the default
values have been selected. After the factory default values have
been reloaded, the display will once again display no.
See Part 4.8 for a list of the default values.
4.4.18 Run Time Cycles for Maintenance
The display will alternately display CyS and the total number
of seconds for the valve to travel from full counterclockwise
to full clockwise then back to full counterclockwise. This
cycle time is measured in the cycle time calibration routine
which is performed after the feedback potentiometer
calibration routine.
The microprocessor converts run time into cycles.
The next screen displays accumulated cycles CyCn. The
number shown represents thousands of cycles. The display
can show up to 9.999 million cycles. Obviously at higher
resolutions, less resolution is available on the display. Only
whole cycles are displayed.
With CyCn displayed, the user can press the SEL switch and
the total will begin flashing. At that point, holding down the
DOWN switch for four seconds will clear the total.
Because the life of EEPROM is based on the number of write
operations, only every 100 cycles will cause the total to be
written to the non-volatile memory.
4.4.19 Alarm Functions
The DEVIATION alarm becomes active if the valve does not
move to the desired position within a certain time period. The
time period is 10 seconds plus either the ramp time for the
direction in which the actuator is moving, or the open/close
time from calibration, whichever is greater.
A means to set UPPER and LOWER rotation alarm limits on
the actuator/valve shaft position is provided. An alarm shall
occur if the positioner rotates beyond either the upper or
lower set limit. The range of rotation limits is from 0 to 100%.
An example of typical alarm limits would be 20% for LOWER
and 80% for UPPER.
An opto isolated open collector/open emitter alarm output will
be on whenever any alarm condition exists.
NOTE: For wiring of alarm outputs refer to diagram at right.
Two alarm parameters will be programmable:
Ahi: 0.0 to 100.0% For the upper rotation alarm.
Alo: 0.0 to 100.0% For the lower rotation alarm.
Load Specs. for Alarm Output:
Maximum Collector/Emitter Voltage is 50 Volts DC
Maximum Collector/Emitter Current is 100 mA
The AdE value is also shown with the programmable
parameters to show the deviation alarm time. This value
cannot be edited.