KROHNE OPTISWITCH 3300C NAMUR EN - Manual (Page 25)

7 Maintenance and fault rectification
7.1 Maintenance
When used as directed in normal operation, OPTISWITCH
3300 C is completely maintenance free.
7.2 Rectify faults
OPTISWITCH 3300 C offers maximum reliability. Nevertheless
faults can occur during operation. These may be caused by the
following, e.g.:
l
Sensor
l
Process
l
Power supply
l
Signal processing
The first measure to be taken is to check the output signal. In
many cases, the causes can be determined this way and the
faults rectified.
?
OPTISWITCH 3300 C signals "covered" when the vibrating
element is not submerged (overfill protection)
?
OPTISWITCH 3300 C signals "uncovered" when the
vibrating element is submerged (dry run protection)
l Supply voltage too low
à
Check the power supply
l Electronics defective
à
Push the characteristics reversal switch. If the instru-
ment then changes the mode, the instrument may be
mechanically damaged. Should the switching function
in the correct mode still be faulty, return the instrument
for repair.
à
Push the characteristics reversal switch. If the instru-
ment then does not change the mode, the oscillator
may be defective. Exchange the oscillator.
à
Check if there is buildup on the vibrating element, and if
so, remove it.
l Unfavourable installation location
à
Mount the instrument at a location in the vessel where
no dead zones or mounds can form.
à
Check if the vibrating element is covered by buildup on
the socket.
Causes of malfunction
Fault rectification
Checking the switching signal
OPTISWITCH 3300 C - with NAMUR output 25
Maintenance and fault rectification
31358
-EN
-060830