FCI ST100A Series, Installation, Operation And Maintenance Manual

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ST100A Series Flow Meter MAINTENANCE
Fluid Components International LLC 91
Lithium Battery Replacement
A 3-volt lithium coin cell battery powers the ST80/ST80L real time clock (RTC). Typical service life of the battery is two years. Replace the
battery every two years with the CR2450N coin cell battery listed in Table 27 below.
Table 27 – Lithium Coin Cell Battery Summary
Qty FCI Assembly P/Ns Description Mfgr. P/N FCI P/N
1 025740-01 (Main Board)
3V Lithium battery type CR2450N,
540 mAh, temperature range: -40 °C
– +85 °C, Manufacturer: Renata
CR2450N 022038-01
Caution: Use only the recommended industrial spec battery listed above. A consumer grade battery will not fit well in the
holder and is prone to leakage or reduced performance or both when used in an industrial environment.
Disassemble the electronics to access the battery. Figure 68 below gives an exploded view of the instrument. Remove the instrument’s
blind lid (refer to instructions in Accessing the I/O Connectors , page 22 ) and follow the disassembly instructions below (skip steps 3
through 6 if unit has no display). The number callouts in the figure correspond to the numbered steps below.
Warning: Make sure system power is OFF before replacing the battery.
1. Remove all user cabling/wiring from the instrument connectors, and then pull all cable/wiring from the cable/wiring ports.
2. Using a 3 mm hex key, remove 2X M4 socket head cap screws securing electronics/cage assembly to housing, and 1X M4 socket
head cap screw securing ground wire to housing. Remove electronics/card cage assembly from housing.
3. Separate bezel/HMI sensor assembly from the cage by pulling straight out.
4. Remove HMI jumper cable from the pin socket at the top the bezel/HMI sensor assembly (
Figure 68 ).
5. Remove 3X 18-8 drive screws securing the display to the cage. Carefully pull the display assembly away from the cage to expose the
FFC (flat flexible cable) cable.
6. Open the FFC cable connector on the main board: Pull the FFC connector lock tab out and then up (away from the board). Once the
lock tab is opened, pull the FFC cable from the connector. Refer to the FFC connector detail in Figure 68. Carefully set aside the fully
detached display assembly.
7. Remove 2X nylon snap rivets securing electronics assembly to the cage, and then slide electronics assembly out to clear the cage.
8. Pull the lithium coin battery from its holder on the main board.
9. Install replacement battery type CR2450N in the coin cell holder with the positive (+) side facing the main board connectors. Use the
replacement battery listed in Table 27 above.
10. Reassembly is reverse of removal. (Make sure FFC display cable is fully inserted and square in connector before pushing the lock tab
back into closed position.)