Burkert Type 8741 - Manual (Page 36)

36
Devicestatus/Troubleshooting
Type 8741
problem possible cause What to do?
Unstable measured value The functional earth (FE) is not properly
connected. Connect the functional earth with the shortest possible cable, cross-
section at least 2.5 mm².
The controller must compensate for irregularities
in an unstable pressure supply caused, for
example, by pumps. Install a suitable pressure regulator in front of the device.
Install a buffer tank to absorb the pressure fluctuations.
The residual ripple on the voltage supply is too
high. Use a suitable supply voltage. See technical data.
Setpoint at 0 % but operating
medium still flows The operating pressure is above the tight sealing
pressure of the proportional valve. Reduce the operating pressure.
To eliminate the defect, return the device to the manufacturer.
Setpoint value at 0 %, valve
is closed, no mass flow, but
a non-zero mass flow rate is
measured The installation position of the device is
incorrect. Install the device in the position indicated on the calibration plate or in
the calibration protocol and run the
AUTOTUNE function to adapt to the
operating conditions.
The device was not calibrated with the operating
medium used. Return the device to the manufacturer for recalibration.
Setpoint value is not reached The inlet filter is clogged. Clean or replace the inlet filter.
The inlet pressure is too low. Increase the inlet pressure to the calibration pressure value.
The outlet pressure is too high. Check whether the fluid connection pipes after the device are dirty and
clean if necessary.
Table 3: Troubleshooting
English