23
System malfunctions
- continued -
Fault finding list for troubleshooting system faults
LED 1 and / or LED 2 – 4 are flashing slowly
Fault:
Sensor line interrupted or interruption in temperature sensor.
Short circuit in temperature senor.
Remedy:
Check sensor lines. Check whether the temperature sensor gives correct readings (see
table “Basic values of measuring resistors” in the installation manual TRV 5-40).
If the readings are not correct replace the measuring insert.
Fault:
Admissible temperature limit in temperature transmitter housing exceeded.
Remedy:
Check place of installation of the temperature transmitter.
LED 1 and / or LEDs 2 – 4 are flashing quickly
Fault:
The
temperature transmitter
and the
control unit
cannot communicate with each other.
Remedy:
Check 24 V bus supply, wiring, configuration of the low level electrodes (wire links), node
ID, baud rate setting and terminating resistors. If modifications have to be made, switch off
mains voltage and switch it on again after about 5 seconds.
Fault finding list for troubleshooting system malfunctions: Control Unit
LED bus status is flashing slowly
Fault:
Faulty communication in the CAN bus system.
Remedy:
Check 24 V bus supply, wiring, configuration of the limiter, node ID, baud rate and
terminating resistors. If modifications have to be made, switch off mains voltage and
switch it on again after about 5seconds.
Fault:
No or faulty communication with limiters. The fault occurs at long intervals.
Remedy:
There is a source of interference in the surrounding area. To suppress interferences provide
contactors and actuators with RC combinations in accordance with the specifications of
the manufacturer. Take action against high frequency interference.
LED Power is flashing slowly
Fault:
Bus supply voltage below 18 V DC. The power supply unit of the controller is overloaded.
Remedy:
Mount and connect a safety power supply unit (e. g. Siemens SITOP Power 05).
Fault:
Bus supply voltage below 18 V DC. Faulty wiring (short circuit).
Remedy:
Check wiring. Switch off mains voltage and switch it on again after about 1 second
(the equipment restarts).
