Load Pick-Up - Siemens SIWAREX WL270 Operating Instructions Manual

Application planning

4.3 Load pick-up

4.3 Load pick-up
Mounting surfaces
For the mounting surfaces of the mounting plates, the following requirements apply:
● The positional and angular deviations of the mounting surfaces to each other should
● Ensure that the foundations are absolutely firm and free of depressions. In concrete
● The mounting surfaces must be vertical to the measuring direction and preferably in one
● A plane of ≤ 0.2 mm is required for the mounting surfaces.
More than three support points
For more than three support points, the load bearing implement is usually statically
indeterminate. With firm foundations and load bearing implements, the load is not evenly
distributed to all load cells. The same applies to unstable mounts such as a steel
construction. Two diagonal load cells bear the main load. The other cells only support the
load bearing implement.
There are two ways to take this into consideration:
● Over-dimensioning of the load cells
● Height compensation of the support points
Over-dimensioning of the load cells
The rated load of the load cells is calculated such that with, for example, four support points
the entire weight can be borne by two load cells.
This also prevents an overload of the load cells if depressions in the foundation have to be
taken into consideration, e.g. for racks in the steel structure.
Height compensation of the support points
With this method, the output signals of all of the load cells are attuned to each other under a
load. To ensure that all of the load cells receive approximately the same load, spacer plates
are used to compensate the heights.
The output signals of the individual load cells correspond to the load distribution.
Proceed as follows to measure the output signals:
1. Disconnect the load cell wires SIG+ and SIG-.
2. Supply the load cells with power from the power supply.
3. Measure the output voltage between SIG+ and SIG- of each individual load cell.
4. Place spacing plates under the load cell bracket with the lowest value until the output
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correspond to the general tolerances for welded constructions in EN ISO 13920.
foundations, flat steel plates should be poured in so that the mounting plates can be
installed on them.
plane.
voltages are equal.
Operating Instructions, 04/2009, A5E02522341B
CP-S SA