°
C = supplement in accordance with ISO 13855:
•
If it is not possible to reach over the protective device: C = 850 mm
•
If it is possible to reach over the protective device, the value C
RO
must be
used for C in accordance with ISO 13855, provided that this is greater
than 850 mm: C ≥ 850 mm and C ≥ C
RO
The reach/approach speed is already included in the formula.
!
"
§
S
Figure 8: Minimum distance from the hazardous point
!
Height of the light beams above ground
"
Hazardous point
§
Depending on the application and distance, persons must be prevented from standing
behind the protective device.
Example calculation
Machine stopping time = 290 ms
Response time after interruption of the light path = 20 ms
T = 290 ms + 20 ms = 310 ms = 0.31 s
S = 1,600 mm/s × 0.31 s + 850 mm = 1,346 mm
4.3.3
Minimum distance from reflective surfaces
Overview
The light beams from the active unit may be deflected by reflective surfaces and disper‐
sive media. This can prevent an object from being detected.
Therefore, all reflective surfaces and objects (e.g., material bins, machine table, etc.)
must maintain a minimum distance (a) from the light beams. This minimum distance
(a) must be maintained on all sides of the light beams. This applies in horizontal, verti‐
cal and diagonal directions as well as at the end of the protective device. The same
area must be free of dispersive media (e.g., dust, fog, or smoke).
The minimum distance (a) depends on the distance (D) between active and passive
unit.
PROJECT PLANNING
4
8024802/2020-07-17 | SICK
O P E R A T I N G I N S T R U C T I O N S | deTem4 LT Muting A/P
21
Subject to change without notice
