71
Logix
®
520MD+ and 510+ Digital Positioners FCD LGENIM0105-15-AQ – 05/16
flowserve.com
YRGR
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FRICTION HIGH WARNING
Description: The valve and actuator friction has passed the user set lim-
it. High friction can cause loop oscillations, poor position control, jerky
motion, or valve sticking. It can be caused by build-up from the process
on the stem, trim or seat , by a failing bearing or guides in the valve
and actuator, galling of the trim or stem, excessively tightened packing,
linkages, or other valve or actuator mechanical issues.
Possible Solutions: Determine if the friction is significantly interfering
with the valve control. If not, consider increasing the friction warning
limit. Consider the following to reduce friction: Stroke the valve to clear
off build-up. Clear any external mechanical obstruction, loosen the
packing, clean the stem, repair or replace the actuator. Highly local-
ized friction or very jerky travel can indicate internal galling. Repair or
replace internal valve components.
YRYY
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BACKLASH WARNING
Description: The amount of detected backlash has passed the user set
warning limit. This may affect valve stability.
Possible Solutions: Check the stem and actuator for loose components.
YRYR
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PNEUMATIC LEAK WARNING
Description: The positioner has detected a leak in the actuation assem-
bly. Leakage from the actuator can cause decreased responsiveness
and excessive air/gas consumption.
Possible Solutions: Repair pneumatic leaks at the tubing junctions and
actuator seals. Check spool valve for excessive wear.
YRRG
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LOW BATTERY WARNING
Description: The battery for the real time clock is low. The battery is
designed for a 15+ year life with the positioner unpowered. The battery
is not required for the positioner to control properly, but is used only to
maintain the time and date upon loss of power. The time and date affect
the time stamps of alarms, warnings and other events. This warning
could be caused by rapidly power cycling the positioner.
Possible Solutions: The battery is not replaceable. Verify or reset the
time and date. Replace the main board if the problem persists for
several days.
YRRY
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PIEZO VOLTAGE HIGH WARNING
PIEZO VOLTAGE LOW WARNING
Description: If the voltage to the piezo is too high, this could indicate an
error with the relay or the main board. This may result from an extend-
ed period of inactivity, but in this case should not persist for more than
30 minutes when the valve is controlling. The positioner may still be
functioning, but have reduced performance under some circumstances.
If the voltage to the piezo is too low, the piezo may be damaged. This
may prevent the proper failure position upon loss of signal/power. This
condition may occur briefly on an air-to-close valve that is held for long
periods of time in the closed position, or an air-to-open valve held in the
open position.
Possible Solutions: Ensure the supply pressure is not low. If alarm
persists for more than 30 minutes, the Piezo assembly is damaged.
Replace the pilot relay.
YRRR
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SPRING UNABLE TO FAIL SAFE WARNING
Description: Upon loss of air supply, the valve may not move to the fail-
safe position. The spring alone is not adequate to overcome the friction
and process load in the system. The system is relying on pneumatic
force to actuate in the direction the spring is pushing. The failsafe
spring may have failed, or it was not sized properly for the application.
Friction or process load may have increased.
Possible Solutions: Repair or replace actuator spring. Check for high
friction. Reduce process load.
RGGG
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COMMAND INPUT BELOW ADC RANGE
COMMAND INPUT ABOVE ADC RANGE
COMMAND INPUT RANGE TOO SMALL
Description: During Command Loop Calibration, the signal was out
of the Analog to Digital Converter (ADC) range, or difference between
the signal at 0% and the signal at 100% was too small. The system is
designed to accept a difference greater than 5 mA and between 10 and
4085 ADC.
Possible Solutions: Recalibrate making sure to use valid command
signal values.
