VEGA VEGABAR 20 - Manual (Page 21)

VEGABAR 20 21
Diagnosis
5 Diagnosis
5.1 Maintenance
VEGABAR process pressure transmitters are
maintenance free.
5.2 Failure removal
Fault signals
VEGABAR provides high reliability with its
self-test and continuous self-monitoring. If
however malfunctions occur, VEGABAR diag-
nosis distinguishes between atypical proc-
ess conditions and faults in the VEGABAR.
Atypical process conditions
Exceeding or not reaching the measuring
range limits (fault signal extinguishes when
the value is again in the measuring range).
Failure in VEGABAR
Failure in the electronics, interferences or
damages in the measuring cell.
The following table assists in analysing the
fault signals.
Reason Fault signal via
DOT-matrix Bargraph Current
Digital indication output
Clearly “OPERATE Bargraph 0 %
outside ???? or 100 % Current
measuring bar“, Digital value value
range no adjust- flashes, tendency 3,6 mA
ment indication or
possible active >21,6 mA
Overload Bargraph 0 %
range or 100 %,
of the for digital value
measuring four segments
cell flash
Failure in “Defect“, all segments
VEGABAR no adjust- flash
ment
possible, no
measuring
function
On instruments with menu-guided adjustment
with additional functions, possible reasons
are displayed under the menu point “Diagno-
sis no.“ in case of failure.
Diagnosis no. Meaning
1 No frequency from C/f-converter
2 Frequency signal of the capacitor
outside the limit values
3 Frequency signal of the reference
capacitor outside the limit values
4 Frequency signal temperature outside
the limit values
7 Communication erro to EEPROM
9 Error in EEPROM CRC-checksum
Troubleshooting
If the indicated value does not correspond to
the level in the vessel or to the process pres-
sure, the following measures must be carried
out:
- check the pressure compensation (only
with overpressure measuring ranges)
- check the electrical connection.
Checking pressure compensation
Open the housing of VEGABAR. The meas-
ured value should not change. However if the
indicated value changes, compensation of
the atmospheric pressure is not ensured and
the measured value will be affected. Check
the breather facility on the VEGABAR-hous-
ing.