Siemens SITRANS F MAG 8000 Standard Operating Instructions Manual page 88

Troubleshooting/FAQs
9.2 Built-in functions
Insulation test
Insulation measurement is working like the normal measurement by excitation of the magnetic
coils in the sensor. Value is checked against a limit of 1.25 mm/s. A value above this limit
results in a failure report.
Measurement will NOT stop if an insulation fault occurs.
Flow value is freezed during insulation test.
Insulation test interval according to register "Insulation Test Interval". Minimum 1 day between
tests.
The insulation test can be enabled/disabled with register "Insulation Test".
When the insulation test is enabled the test starts immediately. All following insulation tests
will start at 00:00:00 (midnight).
Duration of insulation test is 2 min 42 sec (1024 samples @ 6.25 Hz)
Insulation test will always be made with an excitation frequency of 6.25 Hz.
Note
Insulation test cannot be enabled in the MAG 8000 and MAG 8000 CT basic version.
Coil-current test
When H-bridge is turned and just before making samples (4 times each measurement), the
coil current is checked via a comparator. If the coil current is not settled, a failure is reported.
During coil current failure the flow value is forced zero.
Amplifier test
Overload is possible both from the AD conversion of sensor signal and from the pre-amplifier.
These checks are made at each sample and if one of the sample fails with an overload, this
measurement is cancelled and a failure is reported.
During overload detection the coil current is held OFF and the flow value is forced zero.
Checking facilities
The MAG 8000 and MAG 8000 CT are equipped with checking facilities of types P, I, and N.
(2.5.5 in OIML R49). The automatic checks are performed without operator intervention.
Type P permanent checking facilities are automatic checks performed constantly during meter
operation. They include:
● Coil current test
● Amplifier test
● Empty pipe test
● Flow overload
● Pulse overload
88
Operating Instructions, 11/2018, A5E03071515-AE
SITRANS MAG 8000