Panametrics CTF878, Service Manual

Page: 48 / 67

Chapter 5.
38 Model CTF878 Service Manual
5.1.2 Replacing the Fuse
If it has been determined that the fuse in the CTF878 requires replacement, complete the following steps:
WARNING!
The main power to the CTF878 must be disconnected before proceeding.
1. Open the cover on the electronics console. Remove the two mounting screws and lift the clear plastic shroud out
of the electronics console.
2. Locate the black plastic fuse holder that is mounted on the printed circuit board between the power terminal
block TB1 and the RS232 terminal block. As shown in Figure on page 43, the fuse holder extends below the main
aluminum shroud, and the fuse holder cap is located on the bottom of the fuse holder.
3. Using a small standard screwdriver, turn the fuse holder cap counterclockwise about 1/4 turn. The fuse holder
cap, with the captive fuse, will be ejected from the fuse holder.
4. Replace the defective fuse with a new one of the same rating and type. Use only 1-1/4” x 1/4” Slo-Blo fuses, having
a rating as indicated in Table 1 below and on the wiring diagram label.
5. Press the new fuse into the fuse holder cap and insert the fuse into the fuse holder. While applying a slight
pressure with the screwdriver, twist the fuse holder cap 1/4” turn clockwise.
6. Place the clear plastic shroud over the standoffs in the electronics console and secure it in place with its two
mounting screws. Close the cover on the electronics console.
The CTF878 flowmeter may now be placed back into service. Reconnect the main power and resume taking
measurements.
Note: Be sure to record the fuse replacement in Appendix A, Service Record.
Table 1: Line Voltage & Fuse Rating
Line Voltage Fuse Rating
85-264 VAC 1.0 A, Slo-Blo