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 out-
lined 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 flowing
forwards through the pipe.
Measured value reading fluctu-
ates 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 standstill and the measur-
ing 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 Endress+Hauser service
organisation.
Remedial measures
1. Check wiring → Page 35.
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" measuring 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 Endress+Hauser 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 Endress+Hauser
The procedures on Page 8 must be carried out before you return a flowmeter
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 Instruc-
tions.
Replace transmitter electronics
Components in the measuring electronics defective
→
part Page 88
9 Trouble-shooting
→
Increase value
→
Increase value
→
Order spare
85