GE PM880 Operations & Installation Manual page 174

August 2003
Table 9-2: Troubleshooting Guide for Common
Possible Cause
Sensor is contaminated
with conductive parti-
cles (refer to Appendix
A).
Sensor is corroded
(refer to Appendix A).
Sensor temperature is
greater than 70°C
(158°F).
Stream particles caus-
ing abrasion.
Symptom: Screen always reads the wettest (highest) programmed mois-
ture calibration value while displaying dew/frost point.
Probe is saturated. Liq-
uid water present on
sensor surface and/or
across electrical con-
nections.
Shorted circuit on sen-
sor.
Sensor is contaminated
with conductive parti-
cles (refer to Appendix
A).
Improper cable connec-
tion.
9-6
Problems (Continued)
System
Response
Probe reads Clean the sensor and the sensor
high dew point. shield as described in Aluminum
Oxide Probe Maintenance on
page A-9 in Appendix A. Then rein-
stall sensor.
Probe reads too Return probe to factory for evalua-
wet or too dry. tion.
Probe reads too Return probe to factory for evalua-
dry. tion.
Probe reads too Return probe to factory for evalua-
wet or too dry tion.
Clean the sensor and the sensor
shield as described in Aluminum
Oxide Probe Maintenance on
page A-9 in Appendix A. Then rein-
stall sensor.
Run "dry gas" over sensor surface. If
high reading persists, then probe is
probably shorted and should be
returned to the factory for evaluation.
Clean the sensor and the sensor
shield as described in Aluminum
Oxide Probe Maintenance on
page A-9 in Appendix A. Then rein-
stall sensor.
Check the cable connections to both
the probe and the PM880.
Action
Diagnosis and Troubleshooting