Overload Protection - Siemens SIWAREX WL230 SB-S CA Manual

Application planning

4.4 Overload protection

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 load 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
The output signals of the individual load cells correspond to the load distribution.
Compensate for the differences in height as described in the section Compensating differences
in height (Page 24).
4.4 Overload protection
NOTICE
Irreparable faults and damage to the load cells
If load cells are used beyond the maximum working load or the maximum transverse load, this
can cause irreparable faults and even fracturing of the load cell or the compact mounting unit.
● When using load cells with small rated loads, always provide overload protection in order
Overload protection in the measuring direction
You protect load cells against vertical overload by placing a stop screw under the point where
force is introduced. The stop screw limits the measuring path of the load cell.
For load cells with high rated loads, the risk of an unintentional overload is not as great. Take
into consideration possible additional loads when dimensioning the load cells.
Another method for protecting load cells from an overload is to over-dimension the load cells.
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to protect the load cells from becoming damaged. You need overload protection for both
the measuring direction and the transverse direction.
SB-S CA
Manual, 06/2019, A5E47600142-AA