Mettler Toledo IND500x Installationsanleitung Seite 36

When using the terminal with one or more analog load cells, load cell connections are made to the connector
located on the analog load cell option board as shown in the figure below.
Figure 25: Analog Scale Interface (left), installed (right)
The analog load cell option board of the terminal is designed to power up to four 350-ohm load cells (or a
minimum resistance of approximately 87 ohms). To confirm that the load cell load for this installation is within
limits, the total scale resistance (TSR) must be calculated.
To calculate TSR:
TSR =
Ensure that the TSR of the load cell network to be connected to the terminal has a resistance greater than 87
ohms before connecting the load cells. If the resistance is less than 87 ohms, the terminal will not operate
properly.
In addition, the maximum cable distance must be reviewed. The table below provides recommended maximum
cable lengths based on cable gauge and correct operation of the terminal.
Recommended Maximum Cable Lengths
TSR (Ohms)
One to four 350 Ω cells
The following figure shows the terminal definitions on the analog load cell terminal connector J1. Refer to the
manual of the load cell being collected to determine its color code. Color codes of some common platforms are
shown in the table below.
4-WIRE CELLS
LOAD CELL OR JUNCTION BOX
Figure 26: Load Cell Connection
28 Installation​ ​
Load Cell Input Resistance (Ohms)
Number of Load Cells
WARNING
The entity values for the scale base cable must be considered as a safety factor
in the installation. Refer to the Control Drawings #30595335 for entity values
for scale base cables.
24 Gauge (meters/feet)
60 / 200
NOTES:
1. Use 6-conductor shielded wire from home-run
cable.
2. Single 4-wire cells: jumper +EXC to +SEN and
jumper –EXC to –SEN at IND500x terminals.
3. Multiple 4-wire load cells: Jumper +EXC to
+SEN and jumper –EXC to –SEN at junction box
input terminals.
4. Wire size: 16 AWG (1.31 mm2) max., 24
AWG (0.205 mm2) min.
20 Gauge (meters/feet) 16 Gauge (meters/feet)
182 / 600 304 / 1000
6-WIRE CELLS
NOTES:
1. Use 6-conductor shielded wire from
home-run cable.
2. Wire size: 16 AWG (1.31 mm2) max.,
24 AWG (0.205 mm2) min.
LOAD CELL OR JUNCTION BOX
IND500x