14
®
User Instructions Logix 520MD - LGENIM0520-01 11/09
Blink
Code
Description
Recommendations
YYYG
SUPPLY PRESSURE LOW WARning
(user set) indicates that the
supply pressure is below the user set warning limit. Low supply
pressure can cause poor valve response or positioner failure.
The minimum recommended supply pressure is 30 PSI (2.1 bar)
for proper operation. The unit will fail at less than approximately
17 PSI (1.2 bars). Low supply pressure indications can also be
caused by pneumatic leak.
Regulate the supply pressure at the positioner above 30 PSI (2.1 bar). Reca-
librate pressure sensors. Ensure system air/gas supply is adequate. Repair
kinked supply tubing. Check the pressure sensor board connections and replace
pressure sensor board if necessary. Check for pneumatic leaks in the actuator
and actuator tubing. See DTM screen: Health Status/Actuator Health. This
indicator can be disabled.
YYYY
ACTUATiOn RATiO WARning
(user set) indicates a decreased
ability of the system to actuate the valve. It is based on the ratio
of available force to required force to actuate. It is affected by the
process load, friction, spring force, and available supply pressure.
Increase the supply pressure. Reduce the friction. Check the actuator spring.
Resize the actuator. Adjust user set limits. See DTM screen: Health Status/
Actuator Health. This indicator can be disabled.
YRGG
PiLOT RELAY RESPOnSE WARning
(user set) indicates that the
pilot relay is sticking or slow to respond. This affects the respon-
siveness, increases the chance of limit cycling and excessive air
consumption. The pilot relay is part of the inner loop and con-
sists of the driver module assembly with piezo (I-P relay) which
is coupled to the poppet. The value of this indicator corresponds
with inner loop lag. Delayed response can be caused by a partial-
ly clogged piezo or debris, oil, corrosion or low supply pressure.
Check response of the valve. If OK, adjust Pilot Relay Response limits. Check
supply pressure. Replace the piezo or driver module assembly. Maintain a clean,
water-free air/gas supply. See DTM screen: Health Status/Positioner Health.
This indicator can be disabled.
YRGY
FRiCTiOn LOW WARning
(user set) indicates the friction has
passed below the user set limit.
Low friction is usually an indication of improperly loaded packing or seals in the
valve and actuator. See DTM screen: Health Status/Valve Health. This indicator can
be disabled.
YRGR
PnEUMATiC LEAK WARning
(user set) indicates that the positi-
oner has detected a leak in the actuation assembly. Leakage from
the actuator can cause decreased responsiveness and excessive
air/gas consumption. Low supply pressure can also trigger this
warning.
Repair pneumatic leaks at the tubing junctions and actuator seals. Ensure proper
supply pressure. See DTM screen: Health Status/Actuator Health. This indicator
can be disabled.
YRYG
FRiCTiOn HigH WARning
(user set) indicates the valve/actuator
friction has passed the user set limit. 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/actuator mechanical issues.
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 ob-
struction, loosen the packing, clean the stem, repair or replace the actuator. Highly
localized friction or very jerky travel can indicate internal galling. Repair or replace
internal valve components. See DTM screen: Health Status/Valve Health. This
indicator can be disabled.
YRRY
ELECTROniC inAbiLiTY TO FAiL SAFE WARning
indicates that
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 and air-to-open valve held in the
open position.
If alarm persists for more than 30 minutes, the Piezo assembly is damaged and
should be replaced. This indicator can be disabled.
YRRR
PnEUMATiC inAbiLiTY TO FAiL SAFE WARning
indicates that
upon loss of air supply, the valve may not move to the fail-safe
position. The spring alone is not adequate to overcome the fric-
tion and process load in the system. The failsafe spring may have
failed, or it was not sized properly for the application. Friction or
process load may have increased.
Check for high friction. Repair or replace actuator spring. Reduce process load.
This indicator can be disabled.
RGGY
FEEDbACK READing PRObLEM DURing CALibRATiOn ALARM
indicates that during calibration, the range of motion of the positi-
on feedback arm was too small for optimum performance, or the
position sensor was out of range.
Check for loose linkages and/or adjust the feedback pin to a position closer to
the follower arm pivot to create a larger angle of rotation if the feedback rotation
is less than 15 degrees for the total valve travel and recalibrate. Briefly pushing
the quick-cal button acknowledges this condition and the positioner will operate
using the current short stroke calibration if otherwise a good calibration. If the
condition does not clear then adjust the positioner mounting, linkage or feedback
potentiometer to move the position sensor back into range then restart the cali-
bration. This error may be cleared by briefly pushing the quick-cal button, which
will force the positioner to use the parameters from the last good calibration.
RGGR
innER LOOP OFFSET TiME OUT ALARM
during calibration the
Inner Loop Offset value did not settle. This could result in less
accurate positioning.
Repeat the stroke calibration to get a more accurate ILO value. To proceed using
the less accurate ILO value, this error may be cleared by briefly pushing the
quick-cal button. Lowering the gain setting may help if the actuator is unstable
during the calibration. Gain settings can be physically adjusted on the device. A
lower letter represents lower gain.
RGYG
nOn-SETTLE TiME OUT ALARM
indicates that during calibration,
the position feedback sensor did not settle.
Check for loose linkages or a loose positioner sensor. This error may be cleared
by briefly pushing the quick-cal button, which will force the positioner to use
the parameters from the last good calibration. This error may appear on some
very small actuators during the initial calibration. Recalibrating may clear the
problem.
