Siemens LC 500, Sitrans instruction manual Maintenance, Test function, Inspections

Maintenance

Maintenance

Test function

Auto Self-testing

SITRANS LC 500 continuously performs a variety of tests to verify that the device is functioning correctly. These include a test where a known capacitor is applied to the input of the device. The internal results must match the known capacitance value. If a deviation is detected the Fault/Failure can be flagged with a pre-set loop-current (user configurable) and as a status in each HART message.

Manual testing

In order to test the proper processing of signals in PLC/DCS equipment, SITRANS LC 500 allows you to invert the output signal status. In Menu 11, when both buttons are pressed simultaneously, the signal outputs switch to their opposite state. When the buttons are released, the outputs revert to the initial state.

Note: If a Fault or Failure is present, its signal will take precedence over the test function.

If no Fault/Failure is present and no buttons are pressed, the display for menu 11 alternates between two test patterns which together illuminate all the segments of the display. If the loop-current control is in analog mode the loop current will hold the last value, during this test.

Inspections

Under normal circumstances, the SITRANS LC 500 transmitter requires no maintenance. However, we recommend that you schedule periodic inspections of SITRANS LC 500.

The inspection can be subdivided into two parts:

1.Visual Inspection: confirm the following conditions:

a.Inside enclosure is clean and dry.

b.Enclosure sealing is intact and functioning properly (not hardened).

c.All screw connections are tight.

d.Ground connections inside the housing are solid.

e.Ground connections outside the housing are solid.

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