Siemens SITRANS LG250 Operating Instructions Manual page 28

Function test
28
Function test not required
If the parameter check was successful, the adjustment is locked auto-
matically and the instrument is again in safe operating state.
Setup is then finished.
Function test required
Should a function test be necessary, the following message is
displayed on the display and adjustment module. The adjustment
software also signals that a function test is required.
If a function test is required, the switching point or the range must
be controlled with the original medium. For this purpose, you have to
decide for your application which condition is potentially critical.
During a function test, you have to test the safety function of the
instrument in the vessel with the original medium.
For this purpose, you should know the filling height of the vessel as
well as the min. and max. levels respectively for 4 and 20 mA. You
then can calculate the respective output current.
Measure the output current of SITRANS LG250 with a suitable multi-
meter and compare the measured output current with the calculated
output current.
If you have to interrupt the function, you can leave the SITRANS
LG250 in the respective situation.
As long as SITRANS LG250 is powered, the display and adjustment
module remains in the currently set adjustment menu.
To interrupt the function test, you have to push the button "ESC".
If you carry out the function test by means of the "PACTware" soft-
ware, you can store the previously performed tests and continue from
there later on.
If you click to "Complete", the adjustment of the instrument is locked,
but not yet verified. After conclusion of the function test, you have to
restart the adjustment.
If a function test is necessary, please proceed as follows:
Mode overfill protection/dry run protection
Select the respective safety function (overfill protection/dry run pro-
tection) for your application.
1. Raise the level to directly below the switching point
Keep a holding time of 1 minute for each level before you com-
pare the measured value.
2. Lower the level to directly above the switching point
Keep a holding time of 1 minute for each level before you com-
pare the measured value.
Result
SITRANS LG250 - Operating Instructions PBD-51041387