KROHNE BM 100A Handbook - Manual (Page 49)

Handbook BM 100 A 49
4.3 Fault clearing
Event
Fault Action
General Operation
Local Display:
Status Marker
1 displayed
The High Frequency board is not sending a
pulse.
Reason: it may have been damaged by
electrostatic discharge. Contact a KROHNE-authorised
service centre*.
The electronics package may
need to be replaced.
The instrument has lost the level (marker 2)
or interface (marker 4) signal, has searched
in a pre-defined zone and has not yet found
the return pulse.
Reason: The product may have risen into
the dead zone and has dropped below the
threshold due to readings from the flange. Empty tank below dead zone
and check the measurement.
Local Display:
Status Markers
2 or 4 displayed
Reason: The product level may be at zero
(tank empty). Refill tank above minimum level
and check the measurement.
Local Display:
Status Markers
3 and/ or 5
displayed The display is frozen.
Reason: The pulse has dropped below the
threshold, whereupon the gauge opens a
search window / zone. If no reflection is
found, Status Marker 2 (or 4 for interface)
will be displayed.
Marker 3 is also displayed if PC-STAR is
connected and the F7 graphics function has
been selected. Empty tank below dead zone
and check the measurement.
If the signal is not detected then
modify the threshold as shown in
section 3.4.6 using user menu
function 1.5.1 for level and 1.5.4
for interface.
Tank height is not correct.
Check and re-enter tank height
in user function 1.1.1 if required.
Instrument is not
accurate when
working in DIRECT
mode with a
product that has a
high dielectric.
Deposit on the probe or operation in a
heavy dust environment. If the electronics pack has been
replaced, verify that factory
calibration parameters are still
the same. Ask KROHNE* for the
factory calibration sheet and
password for access to the
factory menu.
Electrical Connections and Communication Output
Instrument is wired to the wrong voltage :
fuses have blown. Replace the power supply fuse,
F1, as show in section 4.2.2. The display does
not work.
If the ambient temperature is below
–20°C / –4°F, the LCD does not work Consider using a PC equipped
with KROHNE PC-STAR
software if in a general purpose
area.
On connecting the
instrument to a
DCS unit, the
gauge output
current drops to
3.7 mA or lower. The load resistance in the active loop is
limited to 350Ω. If the DCS load is higher,
then the output current will drop Measure the output load with an
ohmmeter. Modify the load if this
does not conform with the output
option limits. See section 2.2.2.
Output remains at
the same value,
about 16 mA. A power supply has been connected to the
output terminal. The electronics package should
be sent to a KROHNE
authorised service center*.
* A list of KROHNE offices is supplied on the last page of this handbook