Instruction manual

89
MODEL Xmt-P SECTION 10.0
TROUBLESHOOTING
10.2 TROUBLESHOOTING WHEN A FAULT OR WARNING MESSAGE IS SHOWING
Fault message Explanation See Section
RTD Open RTD measuring circuit is open 10.2.1
RTD Ω Overrange RTD resistance is outside the range for Pt 100 or 22k NTC 10.2.1
Broken Glass pH sensing element in pH sensor is broken 10.2.2
Glass Z Too High pH glass impedance exceeds programmed level 10.2.2
ADC Read Error Analog to digital converter failed 10.2.3
Ref Z Too High Reference impedance is too high 10.2.4
EE Buffer Overflow EEPROM buffer overflow 10.2.5
EE Chksum Error EEPROM checksum error 10.2.6
EE Write Error EEPROM write error 10.2.7
Warning message Explanation See Section
pH mV Too High mV signal from pH sensor is too big 10.2.8
No pH Soln GND Solution ground terminal is not connected 10.2.9
Sense Line Open RTD sense line is not connected 10.2.10
Need Factory Cal Transmitter needs factory calibration 10.2.11
Ground >10% Off Bad ground 10.2.12
10.2.1 RTD Open, RTD Ω Overrange, Temperature High, Temperature Low
These messages usually mean that the RTD (or thermistor in the case of the Hx338 and Hx348 sensors) is open or short-
ed or there is an open or short in the connecting wiring.
1. Verify all wiring connections, including wiring in a junction box, if one is being used.
2. Disconnect the RTD IN, RTD SENSE, and RTD RETURN leads or the thermistor leads at the transmitter. Be sure to
note the color of the wire and where it was attached. Measure the resistance between the RTD IN and RETURN leads.
For a thermistor, measure the resistance between the two leads. The resistance should be close to the value in the
table in Section 10.8. If the temperature element is open (infinite resistance) or shorted (very low resistance), replace
the sensor. In the meantime, use manual temperature compensation.