12
Operating instructions
Safety light curtain / safety light grid
SLC440 Series
SLG440 Series
EN
Example
Response time of the safety light curtain = 10 ms
Resolution of the safety light curtain = 14 mm
Stopping time of the machine = 330 ms
S = 2000 mm/s * (330 ms + 10 ms) + 8(14 mm - 14 mm)
S = 680 mm
S ≥ 500 mm, therefore new calculation with K = 1600 mm/s
S = 544 mm
Limit of the hazardous
point
Safety distance (S)
Protection field
marking
Tool - upper part
Signal to stop the
hazardous movement
Standstill of the hazardous
movement
t
n
= t
B
- t
A
Tool - lower part
t
A
S
t
B
≤ 75 mm = max. distance for protection against stepping over
To prevent persons from stepping over the protection field this dimension must be imperatively
respected and observed
Calculation of the safety distance for the multi-beam light grid
SLG440
S = (1600 mm/s * T) + 850mm
S = Safety distance [mm]
T = Total reaction time (machine run-on time, reaction time of the safety
guard, relays, etc)
K = Approach speed 1600 mm/s
C = Safety supplement 850 mm
Example
Reaction time of the SLG440 = 10 ms
Stopping time of the machine T = 170 ms
S = 1600 mm/s * (170 ms + 10 ms) + 850 mm
S = 1138 mm
The following mounting heights must be observed:
Number of
beams
Mounting height above reference floor in mm
2
400, 900
3
300, 700, 1100
4
300, 600, 900, 1200
Safety distance to the hazardous area
S
Hazardous
point
Emitter
Receiver
Command
device
Reset
Mechanical protection
Direction from which
the hazardous area is
accessed
The formulas and calculation examples are related to the vertical set-up
(refer to drawing) of the safety light grid with regard to the hazardous
point Please observe the applicable harmonised EN standards and
possible applicable national regulations
4.5 Increasing the safety distance in the event of risk of a
protection field overlap
If an overlap of the protection field is possible, take care with
the calculation of the safety distance referring to additional
C
RO
according to the table A1 as per norm ISO 13855
The norm ISO 13855 defines two types of safety distances,
- Access
through
the protection area with an additional distance C,
according to the resolution of the AOPD
- Access
over
the protection area with an additional distance C
RO
according to table 1
If it is possible to reach through the hazardous area (vertical alignment)
then both values C and C
RO
have to be determined The higher value
of both is to be used for calculating the safety distance Calculating the
safety distance with C
RO
:
S
C
RO
= K x T + C
RO
K
= Approach speed
T
= Total response time (machine run-on time, response time of the
safety guard, relays, etc)
C
RO
= Additional distance due to protection field overlap to the
hazardous area with part(s) of body
1
2
3
KxT
S
RO
C
RO
a
b
1 Safety sensor
2 Hazardous point
3 Floor
a Height of the hazardous point
b Height of the upper edge of the protection area of the AOPD
