13849-1:2008. The actual speed of the main saw blade
shall be compared with the selected speed continuously.
If the actual speed exceeds the selected speed by more
than 10 % the main saw blade shall stop automatically.
This stop shall be a category 0 stop according EN 60204-
1:2006, 9.2.2. In addition, the following measures against
loss or falsification of data shall be taken:
a) measures against loss of the data for main saw blade
or milling tool selected speed stored in the machine
control if stored data result in an automatic selection of
the intended main saw blade/milling tool speed:
1) safety related data for the machine tools shall be
stored either in 2 independent memory chips or
stored two times in one single chip (one time
inverse);
2) after input of the safety related data for the tools the
data shall be confirmed by the operator;
3) the two data shall be compared automatically at
each switching on of the isolator, at each fetch of the
data, at least once per shift. If the two data are not
identical it shall be impossible to start the spindle
motor or if running the spindle motor shall be
stopped and a warning signal shall be given;
4) for monitoring of failures the processor comparing
the data shall have a watch dog function;
b) measures against falsification in data transfer between
manual control, data stored in the machine control,
display for the data and control of the inverter:
1) selected spindle speed shall be stored in the control
of the inverter or in the unit which monitors the actual
speed;
2) selected speed transmitted to the control of the
inverter or to the unit which monitors the actual
speed shall be read back and monitored on the
display for checking by the operator.
Where a circular saw bench has the facility for grooving
with a milling tool, it shall be possible to operate at a
grooving tool cutting speed of at least 40 m s
-1
with the
allowed tool diameters defined in the instruction manual.
Verification: By checking relevant drawings and/or circuit
diagrams, calculation, inspection of the machine and
relevant functional testing of the machine.
NOTE For the components characteristics a confirmation from
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