Emerson Rosemount Oxymitter 4000, Reference Manual, Page: 119 / 198

8.5 Identify and correct alarm indications
For a transmitter with a membrane keypad, four diagnostic or unit alarm LEDs indicate
faults. A pattern of repeating blinks defines the problem. There is a condensed table of
errors and the corresponding blink codes on the inside right cover of the electronics
housing.
Table 2-8 also identifies the blink code and fault status of each LED as well as the output of
the 4-20 mA signal line and a fault number that corresponds to the troubleshooting
instructions provided in this section.
For a transmitter with the optional LOI, alarm messages are displayed on the LOI display
window, and you can access the alarm status display via the LOI menu.
Table 8-2 displays a
list of alarm/fault messages and the related fault status descriptions and numbers.
Table 8-2: Alarm Messages
Message Status Fault number Self clearing
O2 T/C Open Heater thermoucouple open 1 No
O2 T/C Shorted Heater thermocouple shorted 2 No
O2 T/C Reversed Heater thermocouple polarity reversed 3 No
ADC Error A/D communications error 4 No
O2 Heater Open O
2
heater open 5 No
Very Hi O2 Temp Very high process temperature 6 No
Board Temp Hi Electronics overheated 7 Yes
O2 Temp Low Low process temperature 8 Yes
O2 Temp Hi High process temperature 9 Yes
O2 Cell Open O
2
cell open 10 Yes
O2 Cell Bad O
2
cell failed 11, 13, 14 Yes
EEprom Corrupt EEprom Failed 12 No
Calib Failed Last calibration failed 15 Yes
Line Freq Error Incorrect line frequency detected on power up ` No
8.5.1 Fault 1, Open Thermocouple
The figures below show the electronic assembly for a transmitter with a membrane
keypad and a transmitter with an LOI. The membrane keypad figure also shows J1 and test
points TP1 through TP6, located on the microprocessor board, below the membrane
keypad or the LOI module.
Fault 1, membrane keypad
The
HEATER T/C
LED flashes once, pauses for three seconds, and repeats.
Reference Manual Troubleshoot
00809-0100-4340 October 2019
Rosemount Oxymitter 4000 119