Flowserve 420 IOM - Manual (Page 38)

User Instructions - Logix® 420 Series Digital Positioners FCD LGENIM0106-06 12/13
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38
RRRY
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PIEZO VOLTAGE HIGH ALARM
Description: The voltage driving the piezo is above the alarm
limit. This could indicate an error with the relay or the main
board. The positioner may still be functioning, but have
reduced performance under some circumstances.
PIEZO VOLTAGE LOW ALARM
Description: 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.
RRRR
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POSITION DEVIATION ALARM
Description: The difference between the command and the
actual position has been greater than the user-set limit for
longer than a user-set time.
Possible Solutions: Review active alarms and warnings to
find root causes of this alarm. The deviation settings can be
changed in the Valve Health page of the DTM.