Kistler-Morse KM L-Cell Bolt-On - Manual (Page 34)

Chapter 4. L-Cell Installation on Horizontal Beams
4-9
Wiring L-Cells to Junction Box
Notes
1. Junction box PCB 63-1170-01 is used for L-Cell sets on beams.
Ensure you have this PCB in the junction box (see Figure 4-16).
2. The four small holes in the bottom of the junction box are for wiring
the L-Cells to the junction box.
1. Remove the junction box cover.
2. See Figure 4-15. Place a plastic washer on a watertight fitting. Thread the
L-Cell cable through a cap and watertight fitting. Leave an adequate length
of cable between the L-Cell and fitting to provide a drip loop.
(see Figure 4-16).
3. Spread a generous bead of sealant around the sides of the watertight fitting.
CAUTION
Only use Sikaflex 1A polyurethane sealant or Dow Corning RTV 739 or
RTV 738. Other sealants may contain acetic acid, which is harmful to
sensors and electronics.
4. See Figure 4-16. In the bottom of the junction box, locate one of the four
small holes closest to the terminal you will use for that L-Cell. Screw the
watertight fitting into the hole.
Note
TB3 terminal block has 12 terminals to accommodate up to four L-Cells
(two shear sets). Wire L-Cell A to terminal A and L-Cell B to terminal B. If
there are four L-Cells on one beam, wire L-Cell C to terminal C and L-Cell D
to terminal D.
Sensor position A and B give different signals if mounted on same side of
beam or back-to-back. Correct wiring is very important. See Step 7.
5. Estimate the required length of cable to the terminal strip, allowing a little
extra for strain relief. Cut the excess cable.
6. Strip back 3” (76mm) of the cable sheathing to expose the three wires inside.
Strip back
1 /
4
” (6mm) of insulation from the end of each of the wires.
7. Connect the wires from the left side of the load point and top of sensor
pointing toward load point to the selected TB3 terminals: black wire to B
terminal, white wire to W terminal, and red wire to R terminal. For second
sensor mounted on same side of web or at back side, right side of load point
and top of sensor away from load point, reverse wire: black wire to R
terminal, white wire to W terminal, and red wire to B terminal.
8. Perform Steps 2 through 7 for each L-Cell you wire to this junction box
(up to four).
9. Spread a generous bead of Sikaflex 1A polyurethane sealant or Dow Corning
RTV 739 or RTV 738 around the sides of the plug for each hole not being
used. Screw a plug into each hole.
10. Replace the junction box cover and screws if not ready to begin wiring the
junction boxes together, to ensure no moisture enters the junction box.
Figure 4-15. Inserting
L-Cell Cable through
Watertight Fitting and
Cap
L-Cell Cable
Watertight Fitting
and Cap
Small Hole
12
12
12
12
12
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Plastic
Washer
Sealant