Installation
28
SOLID-4
Leuze electronic
DEUTSCH
E
NGLISH
FRANÇAIS
IT
A
LIANO
ESPAÑOL
N
EDERLANDS
Calculation example for point of operation guarding:
A Safety Light Curtain with a resolution of 20 mm, protective field height 1500 mm is used
on a machine with a stopping time of 150 ms. The response time of the safety interface is
20 ms.
Warning!
Make certain during assembly that it is not possible to reach over, around or under or to
walk behind the protective device.
6.1.2
Safety distance for danger zone guarding
Calculation of the safety distance and required resolution for a Safety Light Curtain for
danger zone guarding.
*)
If this value cannot be achieved because of the safety distance, other measures, e.g. mechanical
barriers, must guarantee the required maximum distance of 50 mm. From 375 mm height above the
floor 75 mm are permissible.
Stopping time of the machine t
Machine
=
150 ms
Response time t
AOPD
=
25 ms
Response time t
Safety interface
=
20 ms
Resolution d of the AOPD
=
20 mm
T = 0.150 s + 0.025 s + 0.020 s
=
0.195 s
S = 2000 x 0.195 + 8 x (20 -14)
=
438 mm
a = Safety distance (S)
b = Measures to prevent access from the sides
c = Height above floor
d = 50 mm – Maximum distance to avoid walking behind*
Fig. 6.1-2:
Safety distance (a) and height (c) for danger zone guarding
a
c
d
