WIKA T15 - Page 25

EN
14139245.01 12/2015 EN/DE
WIKA operating instructions model T15 25
Fault tree
Current loop disconnected
Voltage supply connected
incorrectly (wrong polarity)
Transmitter not connected
Wrong sensor type
Wrong 2-, 3- or
4-wire connection
Wrong temperature
range
Wrong compensation
Sensor
= TE
Sensor
= RTD
l > 20 mA
l < 4 mA
Current value is correct, but a temperature
drift is noticeable while transmitter is heating
up or cooling down
Process temperature out of
measuring range
Sensor break or short circuit
Capacitive or inductive
coupling via the sensor
Capacitive or inductive
coupling via the current
loop
Current value falls while the measured
temperature rises (and the other way around)
Current value is okay at low values, but too
low at higher temperatures
Current value is unstable and changes within
seconds
4 mA < l < 20 mA
but wrong values
l = 0 mA
Sensor connected incorrectly
Wrong transmitter configuration
Wrong polarity of
thermocouple
Load too high
Electromagnetic
interferences
7. Faults