11
SLC 420
SLG 420
Operating instructions
Safety light curtain/safety light grid
EN
Example: Calculation of the safety distance, vertical installation
Total response time T = 220 ms, resolving capability d = 30 mm, height
of the hazardous area 1400 mm, height of the protection area above
the floor 1600 mm
S = K * T + C = 2000 mm/s * 220 ms + 8 (30 -14) = 568 mm
(S > 500 mm, following K = 1600 mm/s)
S = K * T + C = 1600 mm/s * 220 ms + 8 (30 -14) =
480 mm
(S < 500 mm, following S = 500 mm)
S = 500 mm
Safety distance C
RO
S
CRO
= K x T + C
RO
= 1600 mm/s x 220 ms + 650 mm =
1002 mm
S
CRO
> S
ie
Safety distance
S = 1002 mm
If the safety distance of 1002 mm is too large for the application, the
protection field height can be increased from 1600 mm to 1800 mm, this
makes the value C
RO
= 0 mm (table 1)
Result:
By adjusting the protection field height to the value
1800 mm above the floor results in a safety distance:
S = 500 mm
3.5.1 Minimum distance to reflecting surfaces
During the installation, the effects of reflecting surfaces must be taken
into account In case of an incorrect installation, interruptions of the
protection field could possibly not be detected, which could lead to
serious injuries The hereafter-specified minimum distances with regard
to reflecting surfaces (metal walls, floors, ceilings or parts) must be
imperatively observed
8°
8°
a= 262 mm
Access direction
Receiver
Obstacle
Optical axis
Transmitter
Reflecting body
(eg Material container)
Limit of the
hazardous point
a=130mm
5°
5°
Safety distance a
a [mm]
D [m]
0
3 5
10
100
200
300
400
500
600
700
800
900
1000
15
20
Calculate the minimum distance to reflecting surfaces as a function of
the distance with an aperture angles of ± 2.5° degrees or use the value
from the table below:
Distance between transmitter and receiver
[m]
Minimum distance a
[mm]
02 … 30
130
4
175
5
220
7
310
10
440
15
660
Formula: a = tan 2.5° x L [mm]
a = Minimum distance to reflecting surfaces
L = Distance between transmitter and receiver