Process Errors Without Messages - Endress+Hauser PROline prosonic flow 90 Operating Instructions Manual

PROline Prosonic Flow 90
Endress+Hauser
9.4

Process errors without messages

Symptoms
Note:
You may have to change or correct certain settings in functions in the matrix in order to rectify faults. The
functions outlined below, such as DISPLAY DAMPING, for example, are described in detail in the
"Description of Device Functions" manual.
Flow values are negative,
even though the fluid is flow-
ing forwards through the
pipe.
Measured value reading
fluctuates even though flow
is steady.
There are differences
between the flowmeter's
internal totalizer and the
external metering device.
Measured value reading
shown on display, even
though the fluid is at a stand-
still and the measuring tube
is full.
The current output signal is
always 4 mA, irrespective of
the flow signal at any given
time.
The fault cannot be rectified
or some other fault not
described above has
occurred.
In these instances, please
contact your E+H service
organisation.
Remedial measures
o
1. Check wiring Page 33.
If necessary, reverse the connections at terminals "up" and "down".
2. Change the setting in the "INSTALLATION DIRECTION, SENSOR"
function accordingly
1. Check the fluid for presence of gas bubbles.
2. "TIME CONSTANT" function (current output)
3. "DISPLAY DAMPING" function
This symptom is due primarily to backflow in the piping, because the
pulse output cannot subtract in the "STANDARD or SYMMETRY" measur-
ing modes.
The following solution is possible:
Allow for flow in both directions.
1. Check the fluid for presence of gas bubbles.
2. Activate the "LOW FLOW" function, i.e. enter or increase the value for
the switching point.
1. Select the "BUS ADDRESS" function and change the setting to "0".
2. Low flow cut off too high. Reduce the corresponding value in the "LOW
FLOW CUTOFF" functions (ON-/OFF-VALUE).
The following options are available for tackling problems of this nature:
Request the services of an E+H service technician
If you contact our service organisation to have a service technician sent
out, please be ready with the following information:
– Brief description of the fault
– Nameplate specifications (Page 9 ff.): Ordering code and serial
number
Returning devices to E+H
The procedures on Page 8 must be carried out before you return a flowm-
eter requiring repair or calibration to Endress+Hauser.
In all cases, enclose a fully completed "Declaration of contamination"
form with the flowmeter. You will find a preprinted form at the end of these
Operating Instructions.
Replace transmitter electronics
Components in the measuring electronics defective
o
part Page 82
9 Trouble-shooting
o
Increase value
o
Increase value
o
Order spare
79