Malfunctions / Fault Finding - Burkert 8626 Instructions De Service

4

MALFUNCTIONS / FAULT FINDING

Problem
Power LED does not light
LED "Sensor fault" lights
green Power-LED lights
LED "Sensor fault" lights
Power-LED does not light
LED „Overflow-Y" lights
No flow present
Instantaneous value varies
Setpoint value w= 0, valve
closed, no flow;
analogue output erroneous-
ly indicates a small flow
Controller tends to oscillate
46
Possible causes
No power supply
Sensor faulty or power
supply to it interrupted
Device in communication
mode due to excessive
interference
Supply pressure absent or
too low
Installation wrongly
dimensioned
Set value within zero-point
disconnection
No proper PE connection
Controller must continuously
compensate disturbances
from an unstable pressure
supply
Operating pressure
distinctly higher than
calibration pressure
(⇒ enhanced natural
convection)
Operating pressure is far
below the pressure at which
the last autotune has been
taken place (e. g. at factory
calibration)
Calibration medium and
operating medium and their
thermal properties differ
substantially
Remedy
Check the electrical
connections
Send the equipment to the
manufacturer
Reset the device by
switching it off and on;
forthcoming interferences
may be blocked by short-
circuiting pins 5 and 8 at
the 9-pole Sub-D connector
Provide adequate pressure
supply
Correct the performance
data of the fluid compo-
nents (if necessary, also
those of the MFC)
Increase the set value to
> 2% Q
nom
Connect PE to the earthed
conductor point
Install a suitable pressure
regulator upstream
Reduce operating pressure,
alternatively factory
recalibration at the actual
operating pressure
Run autotune to adapt the
device to the actual opera-
ting conditions
Recalibration for the actual
operating medium at the
manufacturer
Type 8626