Emerson Rosemount OCX8800 Instruction Manual page 198

Instruction Manual
IM-106-880C, OI
SB TC Open (Sample block heater thermocouple open)
Probable Cause
Sample block thermocouple or
thermocouple circuit open
O2 TC Shorted (Oxygen sensor heater thermocouple shorted)
Probable Cause
O thermocouple or thermocouple circuit
2
shorted
Slow heatup during cold start
COe TC Shorted (Combustibles sensor heater thermocouple shorted)
Probable Cause
Combustibles sensor thermocouple
shorted
Slow heatup during cold start
SB TC Shorted (Sample block heater thermocouple shorted)
Probable Cause
Sample block thermocouple or
thermocouple circuit shorted
Slow heatup during cold start
O2 TC Reversed (Oxygen sensor heater thermocouple reversed)
Probable Cause
O thermocouple wires reversed
2
COe TC Reversed (Combustibles sensor block heater thermocouple reversed)
Probable Cause
Combustibles thermocouple wires reversed Check combustibles thermocouple wiring per
SB TC Reversed (Sample block heater thermocouple reversed)
Probable Cause
Sample block thermocouple wires reversed Check sample block thermocouple wiring per
Table continued on next page
Fault
Isolation
Recommended Corrective Action
Check sample block thermocouple and circuit wires for breaks or loose
connections per Figure 8-5
failed thermocouple. Perform Reset procedure in Section 3, Configuration and
Startup to continue operation.
Recommended Corrective Action
Check O thermocouple and circuit wires for short circuit condition per
2
8-5 and . Repair shorted wiring or replace failed thermocouple. Perform Reset
procedure in Section 3, Configuration and Startup
Perform Reset procedure in
continue operation. If alarm persists, refer to the O2 Htr Failure alarm
procedure.
Recommended Corrective Action
Check thermocouple resistance (lead to ground) of reference and active
thermocouples per Figure 8-5
ground, replace combustibles sensor.
Perform Reset procedure in
continue operation. If alarm persists, refer to the COe Htr Failure alarm
procedure.
Recommended Corrective Action
Check sample block thermocouple and circuit wires for short circuit condition
per Figure 8-5 and . Repair shorted wiring or replace failed thermocouple.
Perform Reset procedure in
continue operation.
Perform Reset procedure in
continue operation. If alarm persists, refer to the SB Htr Failure alarm
procedure.
Recommended Corrective Action
Check O thermocouple wiring per Figure 8-5 and . Check the wiring at the
2
sensor and inside the electronics housing. Correct reversed-wires fault. Perform
Reset procedure in Section 3, Configuration and Startup to continue operation.
Recommended Corrective Action
at the sensor and inside the electronics housing. Correct reversed-wires fault.
Perform Reset procedure in
continue operation.
Recommended Corrective Action
at the sensor and inside the electronics housing. Correct reversed-wires fault.
Perform Reset procedure in
continue operation.
and Repair breaks or loose connections or replace
to continue operation.
Section 3, Configuration and Startup
and . If either thermocouple is open or shorted to
Section 3, Configuration and Startup
Section 3, Configuration and Startup
Section 3, Configuration and Startup
Figure 8-5
Section 3, Configuration and Startup
Figure 8-5
Section 3, Configuration and Startup
Fault Isolation
April 2017
Figure
to
to
to
to
and . Check the wiring
to
and . Check the wiring
to
17
1