Rice Lake EL204 Signal Trim - Manual (Page 2)

2 EL-204 Installation Instructions
Wiring the Junction Box
The EL-204 junction box has been designed to connect and trim up to four load cells per board. For applications
that use more than four load cells, use the expansion port on the main board to connect an additional junction box.
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 opening. 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 Figure 4 for the
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.)
JP4 PT4 PT3
JP3
JP2 PT1
1
EXP
PT2 JP1
1
CELL4
1
CELL1
1
CELL3
1
CELL2
1
IND
-EX
-SI
SHD
+SI
+EX
M
-SI
S2C
+SI
+EX
-EX
-SI
SHD +SI
+EX
-EX
-SI
SHD
+SI
+EX
+SI
-SI
-EX
SHD
-EX
SHD
+EX
+SE
-SE
1
EXP
1
IND
-SI
+SI
-EX
SHD
+EX
+SE
-SE
Wires to the indicator
If the expansion port is not
used to connect to another
j u n c t i o n b o x , i n d i c a t o r
connections can be made on
either terminal block.
Wires to load cells (both sides)