8. If you are not replacing other electronics, replace the end caps and security latches
(requires a 3 mm Allen wrench). If required, install the security seal wire into and
through one of the two holes in the end cap. Choose holes that minimize
counterclockwise rotation of the end cap when the security wire is taut (maximum
wire diameter .078 inch; 2.0mm) (see Figure 3-19).
9. Adjust the security wire, removing all slack and thread into the lead seal.
10. Cut wire ends to remove excess wire.
11. Apply power to the meter.
This completes the fuse replacement procedure.
3.6.3 Replace Backplane, I.S. Barrier or Power Supply board
The following sections detail removal of the Backplane board, the I.S. Barrier Board and the
Power Supply Board.
Replace the Backplane
1. If replacing the Backplane board, remove power to the meter.
2. Disconnect the Transmitter Electronics Enclosure security seals, loosen the end cap
security latches (3mm Allen wrench required) and remove both end caps (see
Figure 3-19).
3. Remove the CPU Module and the Optional I/O Module (if installed). See Figure 3-17
for board locations and associated terminal blocks.
4. Use a Phillips head screw driver and remove the four Backplane board screws and
captive star washers from the enclosure standoffs.
5. Pull the Backplane board out of the enclosure. This disconnects the I.S. Barrier
Board. Lay the Backplane board down with the Acquisition Cable still attached (the
Power Supply board may remain attached to the Backplane when you remove it
from the enclosure).
Meter repairs
Maintenance and Troubleshooting manual 73