Metek 920, Operator'S Manual With Essential Health And Safety Requirements

Page: 245 / 278

Maintenance and Troubleshooting
|
5-69
MS Code MStatus Alarm Type Condition / Description and Suggested Corrective Action
2 2 Fault f On-board ADC
One or both of the discrete analog-to-digital converters (ADC) is
not responding.
Corrective Action:
Take appropriate safety precautions, open the Electronics Enclo-
sure, and:
• Replace the Microcontroller board. Contact AMETEK to verify
operation before removing this board.
4 3 Fault
f On-Chip ADC
Two possible errors may be occurring, either:
• The Microcontroller board’s internal analog-to-digital (ADC)
converter is not responding.
and/or
• One or more of the RTDs has failed, causing its temperature
zone to read “ 181.4 °C ”.
Upon detection of this fault, the analyzer will automatically switch
to Backpurge mode until the alarm has been corrected.
Note: A temperature zone can indicate “ 181.4 ºC ” but not trigger
this alarm if its Set Point is set to ‘ 0 ’ (typical for a spare
temperature zone).
Corrective Action:
Take appropriate safety precautions, open the Electronics Enclo-
sure, and:
• Replace the Microcontroller board.
and/or
• Check the current temperature ( Show MAI screen) for each
temperature zone and compare it to its Set Point tempera-
ture ( TStPt screen). If a heated external probe is used, press
F1 – 3..4 to check the Probe Temperature (low/high) alarm set
point values.
From RUN mode, press F6 8 and then press 1..8 to check the
current temperature for each temperature zone (including the
External Probe, if used).
• Using an Ohm meter, measure the resistance of the RTD for
the zone which caused the alarm (view the
TType
screen to
determine sensor type). Test it for an open circuit. If the RTD is
faulty, contact AMETEK for assistance.
• Replace the Temperature Daughter board. Contact AMETEK
to verify operation before removing this board.
• Replace the Termination board. Contact AMETEK to verify
operation before removing this board.

(Show MAI) RUN

F6 8

1..8
(TStPt) RUN

F4 0

1..4
(PTPara) RUN

F1 –

3..4
(TType) RUN

F4 4

1..4