Emerson Rosemount OCX8800A Manual page 228

Troubleshoot
December 2022
Recommended actions
Potential cause
Sample block heater open.
Recommended actions
Potential cause
Heater electronics failure.
Recommended actions
Check heater fuse F4 in electronics housing per
•
•
Potential cause
Sensor housing exposed to high wind and/or extreme cold temperatures.
Recommended action
If above causes are not causing the SB heater failure, install flange insulator
(PN 6P00162H01).
9.3.22 Cal Warning or Cal Failed
Calibration warning or calibration failed.
Potential cause
Calibration gas supply low or gas connection leaking.
Recommended actions
228
1. Check sample block heater circuit for broken wire or loose connections
per Figure 9-2 and
2. Repair broken wire or loose connection.
1. Check resistance of sample block heater per
Normal sample block heater resistance is 36.4 Ohms each (18.2 Ohms
with both heaters in parallel).
2. Replace sample block heater if heater is open or has a large resistance.
If open, locate and correct cause of overload.
If F4 is not open or if cause of overload cannot be found, replace
electronics package.
1. Check calibration gas supplies and connections.
2. Adjust gas pressure and flow.
3. Replenish low calibration gas supplies and tighten or repair loose or
leaking connections.
4. When calibration gas supplies are adequate, recalibrate.
Figure 10-8.
00809-0500-4880
Figure 10-8.
Figure 9-1.
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