Endress+Hauser iTEMP PCP TMT 181 Mise En Service page 32

Maintenance, accessories, fault finding
30
Trouble shooting on RTDs (Pt100/Pt500/Pt1000/Ni100)
Fault Cause
Sensor defective
Incorrect RTD connection
Incorrect 2 wire connection
Current
No power supply on the 2 wire
(≤ 3.6 mA or ≥ 21 mA)
connection
Incorrect transmitter programming
(number of wires)
Programming
Head transmitter defective
Sensor is incorrectly installed
Heat dissipation via sensor
Incorrect transmitter programming
(number of wires)
Incorrect or inaccurate
Incorrect transmitter programming
measured value
(Scale)
Wrong RTD set up
Sensor connection (2 wire)
Sensor cable resistance not
compensated (2 wire)
Offset incorrectly set up
Trouble shooting for thermocouple connection (TC)
Fault Cause
Incorrect sensor connection
Sensor defective
Incorrectly set up
Current
(≤ 3.6 mA or ≥ 21 mA)
Incorrect 2 wire connection (current
loop)
No power supply on the 2 wire
connection
Head transmitter defective
Sensor is incorrectly installed
Heat dissipation via sensor
Incorrect transmitter programming
(scale)
Incorrect or inaccurate
Wrong thermocouple set up
measured value
Incorrect comparison set up
Offset incorrectly set up
Fault due to the thermo wire welded
to the well (interference voltages
incurred)
Action/cure
Check sensor
Connect the cables correctly (see
connection diagram)
Connect the cables correctly (see
connection diagram) (Polarity)
Check current loop; the supply
should be >8 V
Change parameter 'connection
mode' (see chap. Operation)
Thermocouple set up (see chap.
Operation). Change to RTD
Replace head transmitter
Reinstall sensor correctly
Monitor sensor installation
positioning
Change parameter 'connection
mode'
Change scale
Change parameter 'sensor type'
Monitor sensor connection
Compensate cable resistance
Monitor offset
Action/cure
Connect the sensor correctly (see
connection diagram) (Polarity)
Check sensor
Sensor type 'RTD' is set up. Set up
the correct thermocouple
Connect the cables correctly (see
connection diagram)
Check current loop; the supply
should be >8 V
Replace head transmitter
Reinstall sensor correctly
Monitor sensor installation positioning
Change scale
Change parameter 'sensor type'
See chap. 'Operation' and
'Technical data'
Check offset
Please use a sensor in which the
thermo wire in not welded