Loop Burnout Alarm (Not Supported For Position-Proportional Models.); Loop Burnout Alarm (Lba) - Omron E5AC-T User Manual

5-10 Loop Burnout Alarm (Not Supported
for Position-proportional Models.)

5-10-1 Loop Burnout Alarm (LBA)

• With a loop burnout alarm, there is assumed to be an error in the control loop if the control deviation
(SP - PV) is greater than the threshold set in the LBA Level parameter and if the control deviation is
not reduced by at least the value set in the LBA Detection Band parameter within the LBA detection
time.
• Loop burnout alarms are detected at the following times.
Set point
LBA
detection
time
(1)
If the control deviation is reduced in the area between 1 and 2 (i.e., the set point is approached) and
the amount the control deviation is reduced is at least equal to the LBA band, the loop burnout alarm
will remain OFF.
The process value is within the LBA level between 3 and 4, and thus loop burnout alarms will not be
detected. (The loop burnout alarm will remain OFF.)
If the process value is outside the LBA level between 4 and 5 and the control deviation is not
reduced by at least the LBA band within the LBA detection time, the loop burnout alarm will turn ON.
If the control deviation is reduced in the area between 5 and 6 (i.e., the set point is approached) and
the amount the control deviation is reduced is at least equal to the LBA band, the loop burnout alarm
will turn OFF.
If the control deviation is reduced in the area between 6 and 7 (i.e., the set point is approached) and
the amount the control deviation is reduced is less than the LBA band, the loop burnout alarm will
turn ON.
• If the LBA detection time, LBA level, LBA detection band, and PID settings are not appropriate,
alarms may be detected inappropriately or alarms may not be output when necessary.
• Loop burnout alarms may be detected if unexpectedly large disturbances occur continuously and
a large deviation does not decrease.
• If a loop burnout occurs when the set point is near the ambient temperature, the temperature
deviation in a steady state may be less than the LBA level, preventing detection of the loop
burnout.
• If the set point is so high or low that it cannot be reached even with a saturated manipulated
variable, a temperature deviation may remain even in a steady state and a loop burnout may be
detected.
• Detection is not possible if a fault occurs that causes an increase in temperature while control is
being applied to increase the temperature (e.g., an SSR short-circuit fault).
E5@C-T Digital Temperature Controllers User's Manual (H185)
Area where
LBA detection
LBA is not
time
detected
(2) (3)
(4)
LBA OFF
5 Advanced Operations
LBA band
LBA band
LBA detection
LBA detection
time
time
(5) (6)
LBA ON LBA OFF
LBA level
LBA level
LBA band
(7)
LBA ON
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