3590EKR, 3590EXP, 3590EXT, 3590 EBOX, CPWE, CPWET series indicator E-AF03_05.01_14.07_EN_T.doc
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ANALOG OUTPUT CABLE
The maximum length of the analogue output cable in current is:
- 100 m with cable 2 x 0,25 mm
2
- 150 m with cable 2 x 0,5 mm
2
- 300 m with cable 2 x 1 mm
2
The maximum length of the analogue output cable in voltage is:
- 50 m with cable 2 x 0,25 mm
2
- 75 m with cable 2 x 0,5 mm
2
- 150 m with cable 2 x 1 mm
2
1.2 EARTHING SYSTEM
For the right earthing and the optimal functioning of the system, it is necessary to connect the indicator, the load cells, the
possible junction box and the weighing structure to the earth.
All earthing cables must have the shortest possible length in order to minimize their resistance.
INDICATOR
Connect the external earthing of the indicator to the earth through copper cables having at least a 16 mm
2
cross-section.
LOAD CELLS AND JUNCTION BOX
The earthing must be done by connecting the earthing cables to a ground bar with cables having a cross-section of at least
16 mm
2
and by connecting the ground bar to a ground pole with a cable having a cross-section of at least 50 mm
2
.
-
In the case the load cells are connected to the indicator through a junction box, it is necessary to connect the sheathing
both of cells cables and of indicator cable to the earthing of the junction box (refer to the junction box manual) and
connect this to the earth through copper cables having at least a 16 mm
2
cross-section.
-
If the load cells are connected directly to the indicator (without the use of the junction box), one should connect the
shieldings of the load cell cables to the grounding point (or earthing bar) inside the container.
-
If the weighing system concerns large and/or outdoor structures, like weighbridges, and the junction box is connected
to the indicator in a distance that is greater than 10 m, or in the presence of noise, the cable shield must be earthed
both in the junction box and in the indicator, and the two ground leads must be connected with an earth cable having a
cross-section of at least 16 mm
2
.
WEIGHING STRUCTURE
Connect the weighing structure and the possible connected structures (for example silos that release material on the
weighing structure) to the earth through copper cables having at least a 16 mm
2
cross-section.
Furthermore it is necessary that for each cell, one connects the upper part with the lower part of the load cell through a
copper braid section not less than 16 mm2; the upper part must be short-circuited with the surface of the weighing structure
and the lower part must be grounded through a copper braid section not less than 16 mm2.
CONNECTED SERIAL CABLES AND INSTRUMENTS
Connect the shield of the serial cable at the grounding point (or grounding bar) inside the container (on the end of the cable
toward the indicator) and at the earth connection of the connected instrument (on the end of the cable toward the indicator),
and ground the earth connection of the connected instrument, through a copper cable section not less than 16 mm
2
.
To avoid possible side effects, the earth references of the connection and power supply cable of the indicator and of the
connected instrument
must be at the same potential
.
