SICK offers a stopping/run-down time measurement service in many countries.
4.3.1.1
Calculating minimum distance from the hazardous point
Important information
DANGER
Minimum distance from the hazardous point is too small
The dangerous state of the machine may not be stopped or not be stopped in a timely
manner due to a minimum distance that is too small.
b
Calculate the minimum distances for the machine in which the single-beam photo‐
electric safety switch is integrated.
b
When mounting the single-beam photoelectric safety switch, observe the minimum
distance.
Approach
The example shows the calculation of the minimum distance for an orthogonal (at right
angles) approach to the single-beam photoelectric safety switch. Depending on the
application and the ambient conditions, a different calculation may be required (e.g., at
a different angle to the direction of approach or an indirect approach).
1.
Calculate S using the following formula:
S = K × T + C
where:
°
S = minimum distance in millimeters (mm)
°
K = approach speed of 1600 mm/s
°
T = machine stopping time + response time of the protective device after
interruption in the light path in seconds (s)
°
C = adjustment factor that depends on the number of beams (1, 2, 3 or 4)
Table 2: Variables for calculating the minimum distance
Number of
beams
1
2
3
4
Height of the
beams above
ground in mm
750
400
900
300
700
1100
300
600
900
1200
Adjustment fac‐
tor C in mm
1200
850
850
850
The reach or approach speed is already included in the formula.
4
PROJECT PLANNING
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O P E R A T I N G I N S T R U C T I O N S | L25
8024678/2020-01-24 | SICK
Subject to change without notice