Emerson OCX 8800 Instruction Manual page 108

OCX 8800
ADC Failure (Voltage to digital conversion could not complete)
ADC Ref Error (Voltage to digital conversion not accurate)
Probable Cause
Incorrect wiring between electronics and sensor
housings
Electronics package failure
O2 Htr Failure (Oxygen sensor heater could not reach final temperature)
Probable Cause
O heater circuit wiring open
2
O heater open
2
Heater electronics failure
COe Htr Failure (Combustibles sensor heater could not reach final temperature)
Probable Cause
COe heater circuit wiring open
COe heater open
Heater electronics failure
SB Htr Failure (Sample block heater could not reach final temperature)
Probable Cause
Sample block heater circuit wiring open
Sample block heater open
Heater electronics failure
Sensor housing exposed to high wind and/or
extreme cold temperatures
8-6
Recommended Corrective Action
Check all wiring between the electronics and sensor housings per Figure 8-3. Correct
wiring faults.
Replace electronics package.
Recommended Corrective Action
Check O cell heater circuit for broken wire or loose connection per Figure 8-3 and
2
Figure 7-4. Repair broken wire or loose connection.
Check resistance of O heater per Figure 7-4. Normal O
2
Ohms. Replace O heater if heater is open or has a large resistance.
2
Check heater fuse F3 in electronics housing per Figure 8-1. If open, locate and correct
cause of overload. If F3 is not open, or if cause of overload cannot be found, replace
electronics package.
Recommended Corrective Action
Check COe heater circuit for broken wire or loose connection per Figure 8-3 and
Figure 7-5. Repair broken wire or loose connection.
Check resistance of COe heater per Figure 7-5. Normal COe heater resistance is 97.7
Ohms. Replace COe heater if heater is open or has a large resistance.
Check heater fuse F3 in electronics housing per Figure 8-1. If open, locate and correct
cause of overload. If F3 is not open, or if cause of overload cannot be found, replace
electronics package.
Recommended Corrective Action
Check sample block heater circuit for broken wire or loose connection per Figure 8-3
and Figure 7-4. Repair broken wire or loose connection.
Check resistance of sample block heater per Figure 7-4. Normal sample block heater
resistance is 36.4 Ohms each (18.2 Ohms with both heaters in parallel). Replace
sample block heater if heater is open or has a large resistance.
Check heater fuse F4 in electronics housing per Figure 8-1. If open, locate and correct
cause of overload. If F4 is not open, or if cause of overload cannot be found, replace
electronics package.
If above probable causes are not causing the SB heater failure, install flange insulator
(PN 6P00162H01).
Table continued on next page
Instruction Manual
IM-106-880, Rev 1.0
January 2007
heater resistance is 62.5
2