Siemens SITRANS LVL200E Operating Instructions Manual page 25

1 Filling the vessel up to
the switching point
MAN-100411
1 Filling the vessel up to the switching point
If this does not cause any problems, you can fill the vessel up to the
switching point and monitor the correct sensor reaction.
2 Dismounting of the sensor and immersion in the original
medium
You can dismount the sensor for test purposes and check its proper
functioning by immersing it in the original product.
3 Short interruption of the supply line to the sensor
The recurring proof test according to IEC 61508 can be carried out
through a short interruption (> 2 seconds) of the supply line to the
sensor. This starts a test sequence.
The correctness of the subsequent switching conditions on the indi-
cations of the SPLC must be monitored. The sensor must neither be
dismounted nor triggered by filling the vessel.
•
Short interruption of the power supply
You can carry out the function test with the outputted current values
also directly via a safety PLC or a process control system.
4 Pushing the test key on the signal conditioning instrument
SITRANS SCSC, SITRANS TCSC
A test key is lowered in the front plate of the signal conditioning instru-
ment. Push the test key for > 2 seconds with a suitable object. Hence
a test is started. The sensor must neither be dismounted nor triggered
by filling the vessel.
With an SPLC (safety-oriented PLC) the correctness of the subse-
quent switching conditions must be monitored via the two LEDs on
the signal conditioning instrument as well as the connected devices.
•
SITRANS SCSC, SITRANS TCSC - by simply checking the failure
LED
With the SITRANS SCSC or SITRANS TCSC signal conditioning
instrument, the test result can be checked directly on an LED on the
signal conditioning instrument.
This is the most comfortable and simple way to carry out the test.
If this does not cause any problems, you can fill the vessel up to the
switching point and monitor the correct sensor reaction.
Procedure
1. Carry out the function test according to the above description (1
Short interruption of the supply line to the sensor.
Separate the instrument briefly (> 2 s) from voltage supply or
push the test key.
Check the results of the test.
Make sure the connected downstream devices are activated dur-
ing the function test.
2. Push the mode switch (min./max.) on the signal conditioning
instrument.
SITRANS LVL200E - Operating Instructions
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