SMAR LD291, Инструкция по эксплуатации и техническому обслуживанию

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Maintenance Procedure
5.3
•
Check the terminal interface connection of the configurator.
•
Check if the interface is connected to the wires leading to the transmitter or to the terminals [ + ]
and [
-
].
•
Check if the interface is models IF3 (for Hart protocol).

Transmitter Connections
•
Check if connections are according to wiring diagram.
•
Check if there is resistance in the 250 Ω line.

Power Supply
•
Check output of power supply. The voltage at the LD291 terminals must be between 12 and 45
Vdc, and ripple less than 500 mV.

Electronic Circuit Failure
•
Locate the failure by alternately testing the transmitter circuit and the interface with spare parts.

Transmitter Address
•
Check if the transmitter address is compatible with the one expected by the configurator.
Symptom: CURRENT OF 21.0 mA or 3.6 mA
Probable Source of Trouble :

Pressure Tap (Piping)
•
Verify if blocking valves are fully open;
•
Check for gas in liquid lines or for liquid in dry lines;
•
Check the specific gravity of process fluid;
•
Check process flanges for sediments;
•
Check the pressure connection;
•
Check if bypass valves are closed;
•
Check if pressure applied is not over upper limit of transmitter's range.
Sensor to Main Circuit Connection
•
Check connection (male and female connectors).

Electronic Circuit Failure
•
Check the sensor circuit for damage by replacing it with a spare one.
•
Replace sensor.
Symptom: INCORRECT OUTPUT
Probable Source of Trouble :

Transmitter Connections
•
Check power supply voltage.
•
Check for intermittent short circuits, open circuits and grounding problems.

Noise Measurement Fluid
•
Adjust damping

Pressure Tap
•
Check for gas in liquid lines and for liquid in steam or gases lines.
•
Check the integrity of the circuit by replacing it with a spare one.