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SITRANS LC500 – OPERATING INSTRUCTIONS
7ML19985GE04
Appendix A
Upper Sensor Limit
The Upper Sensor Limit (USL) is the upper of two limit settings. Whenever the PV value
(Menu Level 0) rises above the upper limit setting, the measurement is considered at fault
and the LCD displays ooL, alternating with PV.
If the display mode is in %, this selection is disabled and the LCD displays - - - -. The
transmitter variable on which this menu selection operates is chosen in Menu 01.
The increment/decrement step size is subject to the setting from Menu 09.
1. Set the rotary switch to C.
2. Press the RED (+) or BLUE (–) button to increase or decrease this value.
or: Press and hold a button to start a repeat function.
or: Press and hold both buttons simultaneously to take the current PV reading as
the new setting.
Delta Range Setting
The Delta Range Setting allows you to commission the unit for overfill or underfill
protection where it is impossible to bring the product to those levels in normal process
conditions. This feature is not normally used for the SITRANS LC500.
Overfill protection is used in applications where the probe is normally uncovered. Delta
Range Setting adds the minimum span to the Lower Range Value: the result is used to
update the Upper Range Value. If the process level exceeds the new URV, a fault is
signalled.
Underfill protection would be used in applications where the probe is normally covered.
In this case, Delta Range Setting subtracts the minimum span from the Upper Range
Value and uses the result to update the Lower Range Value. If the process value drops
below the new LRV, a fault is signalled.
The loop-current control must be in 2-state mode (Menu 07) for Menu 0D to display the Delta
Range Setting. When the loop-current control is in Analog mode, Menu 0D displays - - - -.
Menu
Item
Affected
by:
Rotary
Switch
Position
Left Arrow Description
Values
0C
01, 09
C
Off
Upper Sensor Limit
3300 to 0
Factory setting
3300