7
Optimized layout for A4 print.
i
USER_MAN_ENG_6116EVO
Earthing of the system
For correct earthing and optimal system operation, the load cells, junction box, if any, and weighing structure must be earthed.
LOAD CELLS AND JUNCTION BOX
The connection must be made by connecting the earth wires to the earth bar (cables that must have a cross-section of at least 16 mm
2
);
finally, connect the earth bar to the earth post with a cable having a cross-section of at least 50 mm
2
.
EXAMPLES:
•
If the load cells are connected to the board through a junction box, the cable shield from the board and the cell cable shields must be
connected to the earth socket of the junction box (refer to the junction box manual) and the junction box must be earthed using a copper
cable with a cross-section of not less than 16 mm
2
.
•
If the load cells are connected directly to the board (without using the junction box), the cell cable shields must be connected to the
earthing point (or earth bar).
•
If the weighing system involves large and/or outdoor structures (weighbridges, silos, etc.) and the distance between the junction box
and the weight board is greater than 10 m, connect the cell cable shields to the earth socket in the junction box.
WEIGHING STRUCTURE
Earth the weighing structure and/or any unconnected structures (e.g. silos that release material onto the weighing structure) using cables
with a cross-section of not less than 16 mm
2
.
Also connect the upper part with the lower part of each cell by means of a copper braid with a cross-section not less than 16 mm
2
(refer
to the
earthing examples on page 12 and page 13
)
.
SERIAL CABLES AND CONNECTED INSTRUMENTS
Connect the serial cable shield to the earthing point (or earth bar) inside the panel. To avoid any undesired effects, the earth reference
of the connection cable, power supply and transmitter must be at the same potential.
PC
The 6116EVO is earthed through the power cable.
WARNING: Check that the power supply socket to which the 6116EVO Industrial PC will be connected has an earth line.
GENERAL NOTES:
•
All earth wires must be of suitable length, so as to obtain an overall resistance of the earthing system of less than 1 Ω.
•
If the weighing system involves large and/or outdoor structures (weighbridges, silos, etc.):
- the earth connection must be made by connecting the earth wires to an earth bar and the earth bar to the earth post with
a cable having a cross-section of not less than 50 mm
2
;
- the thickness of the cables must be greater (50 mm
2
instead of 16 mm
2
and 100 mm
2
instead of 50 mm
2
), because the
voltages at stake are greater (e.g. lightning);
- the earth post must be placed at a distance of at least 10 m from the structure.
•
If the load receiver is more than 10 m from the transmitter, we recommend using the SENSE line and load cells equipped
with a (SENSE) compensation circuit.
