Emerson Rosemount OCX 8800 Reference Manual page 116

Foundation Fieldbus
Table 7-3: Descriptions of PlantWeb Alerts
Alerts Alarms
Sensor Heater Transducer block:
Over Tempera- 1. O
ture Very High
2. Comb Temp.
Very High
3. SB Temp. Very
High
Sensor Heater Transducer block:
Temperature Var- 1. O
iance Low
2. O
High
3. Comb Temp.
Low
4. Comb Temp.
High
5. SB Temp. Low
6. SB Temp.
High
Calibration Error Transducer block:
1. O
Failed
2. Comb Calibra-
tion Failed
3. Calibration
Warning
106
(continued)
AMS tab
T/C Heater Alerts
Cell Temp.
2
T/C Heater Alerts
Cell Temp.
2
Cell Temp.
2
Calibration Alerts
Calibration
2
What does the Recommended
alert indicate? action
This alert indi- Check heater wir-
cates a very high ing, check ther-
heater tempera- mocouple wiring,
ture; temperature or replace the
is rising too fast. electronics stack.
This alert indi- Allow instruments
cates a sensor several minutes to
heater tempera- reach proper tem-
ture that is too perature or check
high or too low. power supply.
This alert indi- Check the calibra-
cates that the tion gas supplies
slope and con- and connections.
stant values de-
termined from
the calibration did
not fall within an
acceptable range.
Description
A heater over-
temperature/out
of control prob-
lem is generally
cause by the in-
ability of the de-
vice to limit pow-
er to the heater.
This could be
caused by a shor-
ted triac on the
power supply in
the electronics
stack.
Cell temperature
may become er-
ratic for the fol-
lowing reasons:
1. Temperature
is settling dur-
ing startup.
2. Large varia-
tions in proc-
ess tempera-
ture or flow.
3. Fluctuations
or noise in the
power sup-
plied to the in-
strument.
Make sure the
oxygen concen-
trations of the cal-
ibration gases
match the con-
centration values
in the device. If
the calibration
has been per-
formed correctly,
this alarm may in-
dicate that the
sensor requires
replacement. Re-
fer to Section 8.2
for details.
OCX 8800