Emerson Rosemount OCX8800A Manual page 224

Troubleshoot
December 2022
9.3.12 O2 TC Shorted
Oxygen sensor heater thermocouple shorted.
Potential cause
O thermocouple or thermocouple circuit shorted.
2
Recommended actions
Potential cause
Slow heat up during cold start.
Recommended actions
9.3.13 COe TC Shorted
Combustibles sensor heater thermocouple shorted.
Potential cause
Combustibles sensor thermocouple shorted.
Recommended actions
Potential cause
Slow heat up during cold start.
Recommended actions
9.3.14 SB TC Shorted
Sample block heater thermocouple shorted.
Potential cause
Sample block thermocouple or thermocouple circuit shorted.
224
1. Check O thermocouple and circuit wires for short circuit condition per
2
Figure 9-2 and Figure
2. Repair shorted wire or replace failed thermocouple.
3. Perform Reset to continue operation.
1. Perform Reset to continue operation.
2. If alarm persists, refer to
1. Check thermocouple resistance (lead to ground) of reference and active
thermocouples per
2. If either thermocouple is open or shorted to ground, replace
combustibles sensor.
1. Perform Reset to continue operation.
2. If alarm persists, refer to
10-8.
O2 Htr Failure.
Figure 9-2 and Figure
COe Htr Failure.
00809-0500-4880
10-9.
Emerson.com/Rosemount
Manual