Chapter 5 Operating Instructions
C 4000 Standard/Advanced
38 © SICK AG • Industrial Safety Systems • Germany • All rights reserved 8 009 861/OE59/19-11-04
Installation and mounting
How to calculate the safety distance S according to EN 999 and EN 294:
The following calculation shows an example calculation of the safety distance. Depending
on the application and the ambient conditions, a different calculation may be necessary.
First, calculate S using the following formula:
S = 2000 × T + 8 × (d – 14) [mm]
Where …
T = Stopping/run-down time of the machine
+ response time of the protective device after light path interruption [s]
d = Resolution of the light curtain [mm]
S = Safety distance [mm]
The reach/approach speed is already included in the formula.
If the result S is ≤ 500 mm, then use the determined value as the safety distance.
If the result S is > 500 mm, then recalculate S as follows:
S = 1600 × T + 8 × (d – 14) [mm]
If the new value S is > 500 mm, then use the newly determined value as the minimum
safety distance.
If the new value S is ≤ 500 mm, then use 500 mm as the safety distance.
Example:
Stopping/run-down time of the machine = 290 ms
Response time after light path interruption = 30 ms
Resolution of the light curtain = 14 mm
T = 290 ms + 30 ms = 320 ms = 0.32 s
S = 2000 × 0.32 + 8 × (14 – 14) = 640 mm
S > 500 mm, therefore:
S = 1600 × 0.32 + 8 × (14 – 14) = 512 mm
Fig. 20: Safety distance from
the hazardous point
Note
Hazard-
ous
point
Distance to avoid
tanding behind the light curtain
75 mm
Safety distance S (D
s
)
Protective field height