Burkert Type 8709 User Manual
Page 44

44
Maintenance, Troubleshooting
problem
possible cause
remedial action
No flow-rate available
The set-point value is below the limit for
the zero point shut-off.
Increase set-point value to > 10% of the
nominal flow-rate.
The device is in an operating state other
than standard controlled operation.
Check operating state, see also Chapter
8.3. Functions of the LFC / LFM.
The pipelines have been sized too large
or may not yet have been completely
deaerated.
Deaerate lines.
Change pipe size.
Actual value fluctuates
FE connection not correct.
Connect FE to the earthing point (as
short as possible, wire at least 2.5 mm²).
The controller is continuously correcting
malfunctions in an unstable pressure
supply, e.g. by pumping.
Connect suitable pressure controller
upstream.
Install buffer tank to absorb pressure
fluctuations.
The residual ripple of the power supply
voltage is too high.
Use power supply with a smooth output
voltage at the required power.
Set-point value = 0%,
flow-rate still available
The operating pressure is above the
maximum operating pressure of the valve.
Reduce the operating pressure.
Return device to the manufacturer to
have the fault repaired.
Set-point value = 0%,
valve is closed,
no flow-rate available;
however, actual value
output indicates a low
flow-rate
The mounting position of the device is
incorrect.
Install LFC in the calibrated mounting
position and run an Autotune function to
adjust to the operating conditions.
A fluid is used other than that designated
by the calibration.
Return device to the manufacturer for
recalibration for the operating fluid.
Set-point value is not
reached
The filter is blocked.
Clean or replace filter.
The primary pressure is too low.
Increase primary pressure to calibration
pressure.
The back pressure is too high.
Check system components for soiling on
output side and if required clean.
Malfunctions
Table 10:
english
Type 8718, 8719 / 8708, 8709