Operating Instructions

iTEMP TMT72 Diagnostics and troubleshooting
Endress+Hauser 35
9 Diagnostics and troubleshooting
9.1 General troubleshooting
Always start troubleshooting with the checklists below if faults occur after startup or
during operation. The checklists take you directly (via various queries) to the cause of the
problem and the appropriate remedial measures.
Due to its design, the device cannot be repaired. However, it is possible to send the
device in for examination. See the information in the "Return" section. .→  41
General errors
Problem Possible cause Remedy
Device is not responding. Supply voltage does not match that
specified on the nameplate.
Check the voltage at the transmitter
directly using a voltmeter and correct.
Connecting cables are not in contact
with the terminals.
Check the contacting of the cables and
correct if necessary.
Electronics unit is defective. Replace the device.
Output current < 3.6 mA Signal line is not wired correctly. Check wiring.
Electronics unit is defective. Replace the device.
HART communication is not
working.
Missing or incorrectly installed
communication resistor.
Install the communication resistor (250
Ω) correctly.
Commubox is connected incorrectly. Connect Commubox correctly.
Commubox is not set to "HART". Set Commubox selector switch to
"HART".

Check display (optionally in conjunction with head transmitter)
Problem Possible cause Remedy
No display visible
No supply voltage • Check the supply voltage at the head
transmitter, terminals + and -.
• Ensure that the display module
holders are correctly seated and that
the display module is properly
connected to the head
transmitter→  10.
• If possible, test the display module
with other suitable head transmitters,
e.g. an Endress+Hauser head
transmitter.
The display module is defective. Replace the module.
The electronics of the head
transmitter are defective.
Replace the head transmitter.

Local error messages on the display
→  37