20
MAN-100414
SITRANS TCSC - Operating Instructions
55492-EN-170907
7 Maintenance and fault rectification
7.1 Maintenance
If the device is used properly, no special maintenance is required in
normal operation.
7.2 Rectify faults
Maximum reliability is ensured. Nevertheless, faults can occur during
operation. These may be caused by the following, e.g.:
•
Measured value from sensor not correct
•
Voltage supply
•
Interference in the cables
The first measure to be taken is to check the input and output signals.
The procedure is described as follows. In many cases the causes can
be determined this way and faults can be easily rectified.
Depending on the reason for the fault and the measures taken, the
steps described in chapter "Set up" may have to be carried out again.
Cause
Rectification
Sensor not connected
correctly
•
In Ex systems, make sure that the Ex protection
is not influenced by the measuring instruments
used.
•
Measure the current and voltage on the connec-
tion cable to the sensor
•
Faults in the sensor causing a current change to
below 3.6 mA or over 21 mA lead to a fault signal
in the signal conditioning instruments.
•
The terminal voltage must be inside the specified
range. You can find this voltage range in the oper
-
ating instructions of the connected sensor.
Sensor delivers no (cor-
rect) switch-on pulse
•
Use sensor with switching-on pulse
•
Deactivate switch-on pulse monitoring
Causes of malfunction
Fault rectification
Reaction after fault recti-
fication
Red fault LED lights up
