Emerson Series 3000 MVD User Manual

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Low pickoff voltage can be caused by several problems. See Table 22-13.

Two core processor procedures are available:

•

You can check the core processor LED. The core processor has an LED that indicates different 
flowmeter conditions. See Table 22-14.

•

If an A026 alarm is present, you can perform the core processor resistance test to check for a 
damaged core processor.

To check the core processor LED:

1. Maintain power to the transmitter.

2. Remove the core processor lid. The core processor is instrinsically safe and can be opened in 

all environments. Do not disconnect the 4-wire cable between the core processor and the 
transmitter.

3. Check the core processor LED against the conditions described in Table 22-14 (standard core 

processor) or Table 22-15 (enhanced core processor).

4. To return to normal operation, replace the lid.

Wrong K1 characterization constant for sensor

Re-enter the K1 characterization constant. See 
Section 7.3.3.

Polarity of pick-off reversed or polarity of drive reversed

Contact Micro Motion.

Slug flow

Verify flow tubes are completely full of process fluid.

Foreign material caught in flow tubes

Purge flow tubes.

Faulty wiring runs between the sensor and core processor

Verify wiring. See Section 22.11.2.

Process flow rate beyond the limits of the sensor

Verify that the process flow rate is not out of range of the 
sensor.

Slug flow

Verify flow tubes are completely full of process fluid.

No tube vibration in sensor

Check for plugging.

Verify power to transmitter.

Ensure sensor is free to vibrate (no mechanical binding).

Verify wiring. See Section 22.11.2.

Test coils at sensor. See Section 22.20.

Moisture in the sensor electronics

Eliminate the moisture in the sensor electronics.

The sensor is damaged

Contact Micro Motion.