Rice Lake EL204 User Manual
EL-204
Installation Instructions
For PN 73428
The EL-204 is a signal trim junction box that can accommodate up to four load cells.
It has an ABS molded enclosure and molded-in nylon compression cable fittings that provide an extra waterproof
Figure 1 illustrates the EL-204 junction box with its six-screw attachment lid removed.
seal.
Figure 1. EL-204 Junction Box
EL-204 Junction Box Mounting Procedure
Mount the junction box in a location convenien t for servicing and away from standing water. Try to mount the
enclosure in a location so that the load cell cables need not be cut, nor length added. Load cell output is
temperature compensated for the supplied cable length. Altering that length can change the cell’s signal output.
Depending on the mounting surface, the EL-204 enclosure can be attached using two pan-head screws, bolts or
other suitable fasteners. Figure 2, below, shows the dimensions for mounting the enclosure.
Figure 2. EL-204 Enclosure Dimensions
January 2007 98088
Wiring the Junction Box
The EL-204 junction box has been designed to connect and trim up to four load cells pe r board. For applications
that use more than four load cells, use the expansion port on the main board to connect an additional junction box.
EXP
IND
If the expansion port is not
used to connect to another
junction box, indicator
connections can be made on
either terminal block.
1
+EX
+SE
Wires to the indicator
-EX
-SE
+SI
-SI
1
SHD
+EX
-EX
+SI
-SI
SHD
SHD
-SI
+SI
-EX
+EX
CELL1
1
1
M
CELL4
JP1
PT1
EXP
IND
+EX
+SE
-EX
-SE
+SI
-SI
1
SHD
JP4
PT4 PT3
CELL2
JP2
PT2
1
JP3
+EX
-EX
+SI
-SI
1
SHD
SHD
-SI
+SI
-EX
S2C
1
CELL3
+EX
Wires to load cells (both sides)
Figure 3. Expansion Board Wiring Location
After determining the wiring pattern, route the load cell cables through the cord grip assemblies and leave the grips
loose until final closure. Before connecting the load cell wires to the terminals, strip the wire insulation back 1/4"
to expose the wire. The spring loaded terminals will accommodate 12 to 28 gauge wire. To connect the load cell
wires to the appropriate connectors, push in the quick-connect level with a small screwdriver. While holding the
lever, insert the appropriate wire into the exposed wire open ing. Release the screwdriver to allow the spring-loaded
gate to close and lock the wire into place.
The indicator terminal strip, which is located on the expansion port is used to connect the main home run cable to
the indicator. Determine the indicator’s load cell input connections from the indicator operating manual. Run a
cable from the indicator into the junction box through the larger cord grip and connect to the indicator terminal
strip.
Trimming Procedure
Trimming is a process of equalizing the output from multiple individual load cells. If needed, load cell output can
be individually trimmed with potentiometers.
Whenever a substantial amount of trim (more than 5% of normal output), seems necessary to equalize output check
for other possible problems. The best trim is always the least amount of time. When all errors except cell mismatch
and cable extensions or reductions have been corrected, continue with the trimming.
Use the following steps to properly trim the EL-204 junction box.
1. Determine the number of load cells needed.
2. Make sure the jumpers are in place to enable trimming of the desired cells corresponding to each load cell
in use. If you have any unused cells, remove the jumpers corresponding to those cells. See
location of jumpers JP1, JP2, JP3, and JP4.
3. Set all potentiometers fully clockwise to give maximum signal output from each cell. (See the location of
the potentiometers in
Figure 4.)
Figure 4 for the
2 EL-204 Installation Instructions
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