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GuardShield™ Safe 4 Safety Light Curtain User Manual
-> If the result S is > 500 mm (19.6 in.), then recalculate S as follows:
S = 1600 × T + 8 × (d – 14) [mm]
-> If the new value S is > 500 mm (19.6 in.), then use the newly
determined value as the minimum safety distance.
-> If the new value S is ≤ 500 mm (19.6 in.), then use 500 mm
(19.6 in.) as the safety distance.
Example:
Stopping/run-down time of the machine = 290 ms
Response time = 30 ms
Resolution of the light curtain = 14 mm (0.55 in.)
T = 290 ms + 30 ms = 320 ms = 0.32 s
S = 2000 × 0.32 + 8 × (14 – 14) = 640 mm (25.1 in.)
S > 500 mm, therefore:
S = 1600 × 0.32 + 8 × (14 – 14) = 512 mm (20.1 in.)
How to Calculate the Safety Distance S for
GuardShield Safe 4 PAC Systems
In the case of perimeter systems or light curtains with a resolution d > 40
mm, the safety distance is calculated for vertical mounting light curtains
and horizontal approach, according to the formula:
S = 1.6 mm/ms x T + 850 mm
More detailed information regarding safety distance and safety heights
can be found in standard EN 13855 (2010).
Minimum Distance from Reflecting Surfaces
The infrared light from the sender may be reflected off of shiny surfaces
and be received by the system's receiver. If this condition occurs, it can
result in an object not being detected when it enters the GuardShield
Safe 4 sensing field.
All reflecting surfaces and objects (e.g. material bins) must therefore be
located at a minimum distance a from the protective field of the system.
The minimum distance a depends on the distance D between sender and
receiver.
Distance D (meters)
Figure 4: Minimum distance from reflecting surfaces
How to Determine the Minimum Distance from the Reflecting Surfaces:
• Determine the distance D [m] sender-receiver
• Read the minimum distance a [mm] from the graph:
8
Figure 5: Graph, minimum distance from reflecting surfaces
The effective aperture angle for the GuardShield Safe 4 system is
±2.5° at a mounting distance of > 3.0 m (9.8 ft). Calculate the minimum
distance to reflecting surfaces depending on the distance between the
transmitter and the receiver, using an aperture angle of ±2.5°, or take the
appropriate value from the following table:
Formula: a = tan 2.5° x D [mm]
a = minimum distance to reflecting surfaces
D = distance between transmitter and receiver
Installation and Mounting
This section describes the preparation, selection and installation of the
GuardShield Safe 4 safety light curtain. Mount and connect both
transmitter and receiver.
IMPORTANT
Determine if the machinery, on which the GuardShield Safe 4 is to be
mounted, meets the requirements as specified in the beginning of this
manual, i.e., machinery must be able to be stopped anywhere in its stroke
or cycle, consistently and repeatedly.
Original instructions
Distance Between
Transmitter and Receiver
(Range D) [m (ft)]
0...3.0 (0...9.8)
4.0 (13.1)
5.0 (16.4)
6.0 (19.6)
7.0 (22.9)
10.0 (32.8)
16.0 (52.4)
The installation of the GuardShield Safe 4
safety light curtain must be such that access
to the hazard is only possible through the
sensing field of the GuardShield Safe 4.
Auxiliary safe guarding may be required in
conjunction with the GuardShield Safe 4 to
meet this requirement.
Minimum Distance
a [mm (in.)]
135 (5.31)
175 (6.88)
220 (8.66)
265 (10.43)
310 (12.2)
440 (17.32)
700 (27.55)
R
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