ABB XFC Series Flow Computer Maintenance Guide

The real-time operating system running on XFC is based on object-oriented design and supports users to instantiated various "software objects" (Applications) as needed. The following are the most commonly used applications and their maintenance points.

5.1 Calculation of AGA3 Orifice Meter Run

Configuration points:

Enter the aperture of the orifice plate, the inner diameter of the pipeline, and the pressure tapping method (flange/corner joint/diameter distance).

Select gas composition parameters (AGA8 or NX-19).

Set upper and lower limit alarm values for differential pressure, static pressure, and temperature.

common problem:

Phenomenon: The flow calculation value is significantly larger or smaller.

Reason: Incorrect input of orifice plate parameters (such as reverse filling of aperture and pipeline inner diameter); Or incorrect selection of gas density calculation (e.g. wet natural gas should use AGA8 Detail instead of NX-19).

Solution: Verify the bid data and use PCCU32 to check and correct the object parameters.

5.2 Real time Data Logger

XFC defaults to storing 45 days of hourly and daily data, as well as 200 event records. Users can customize the recording frequency and triggering conditions.

Maintenance operation:

Regularly download historical data to avoid the coverage of critical events by circular buffers.

If abnormal storage data is found (such as recording gaps), check whether the lithium battery (3V) is depleted. This battery is used for SRAM data backup. If the main battery fails after power failure, the data will be lost.

5.3 Valve Control and Calibration

Suitable for pressure regulation or flow regulation circuits. XFC can execute PID control and output 4-20mA to the locator through the TFIO module, while reading valve feedback.

Valve calibration steps:

Create a 'Valve Control' object in PCCU32.

Set control mode (analog output or digital pulse).

Execute 'Auto Tune' or manually set dead zone and gain.

Troubleshooting: If the valve vibrates, the dead zone is usually set too small or the actuator responds too quickly; If the response is too slow, increase the gain or decrease the integration time.

Power management and battery maintenance

XFC relies on 12V DC lead-acid batteries for power supply and supports charging with solar panels, AC-DC power sources, or DC-DC converters.

6.1 Power consumption estimation

The XFC substrate (FC195) has extremely low power consumption, with a typical operating current of only 8mA (approximately 100mW). For every additional TFIO module added, there will be an increase of approximately 1-2mA. For remote sites that communicate only a few times a day, a 26Ah battery can support several months of operation.

6.2 Battery replacement steps

Warning: Before replacing the battery, it is necessary to ensure that there are no explosive gases on site. XFC is an Ex nA or Class I Div 2 device, and must comply with hazardous area regulations when operating with electricity.

Disconnect the external charging power supply.

Use PCCU32 to execute the 'Shutdown' command to put the device into a safe shutdown state.

Open the battery compartment cover (located below or on the side of the main electronic compartment, depending on the model).

Disconnect the battery connector (first negative, then positive).

Remove the old battery (note that lead-acid batteries are heavy to prevent them from falling).

Insert a new battery and connect the positive and negative poles.

Close the battery compartment cover and reconnect the charging power source. The device will automatically start.

Charger parameters:

Solar panel: nominal voltage 16-18V, power selected according to the sunlight conditions of the site (usually 10-30W).

External DC: 16-18V, current limited.

Fault diagnosis:

Phenomenon: The voltage display is below 11.5V, and the device frequently resets.

Reason: battery aging; Or insufficient charging (solar panel obstructed, charger damaged).

Check: Measure the voltage at the charging end. If there is no charging voltage during the day, check the diodes inside the solar panel and junction box.

Phenomenon: The voltage is normal but the device cannot start.

Reason: The internal fuse (PTC positive temperature coefficient thermistor) broke due to instantaneous overcurrent. After power-off cooling, it can be restored on its own. If it trips repeatedly, it is necessary to check for external wiring short circuits.

Common alarm codes and their handling

XFC outputs alarm information through local LCD display and remote communication. The following are the most common alarms and their countermeasures:

Alarm code/information meaning processing measures

Check if the internal flat cable is loose due to communication interruption between the XIMV Comm Fail main CPU and XIMV sensor; Power off and restart; If it still fails, XIMV needs to be replaced (requiring factory calibration).

DP Zero Out of Range: If the differential pressure zero point exceeds the acceptable range, check whether the pressure pipe is blocked or leaking; Perform zero point adjustment; If the alarm continues, the sensor may be damaged.

Battery Low: Check the charging system if the battery voltage is below 11.0V; Replace the battery.