Calculating Minimum Distances; Safety Distance For Danger Point Guarding - Siemens SIMATIC FS400 Anleitung

6.1

Calculating minimum distances

Light curtains can only perform their protective function if they are mounted with a
sufficient safety distance.
The calculation formulas for the safety distance depend on the type of protection. In the
harmonized European standard EN 999/ISO 13855, "Positioning of protective devices
with regard to approach speeds of parts of the human body", the installation situations
and calculation formulas for safety distance are described for the following protection
types:
The formula for the required distances to reflective surfaces is based on the European
standard for "Active opto-electronic protective devices" pr EN IEC 61496-2.
In accordance with ISO 13855, the machine response times given in the following must
contain at least an additional 10 %.

6.1.1 Safety distance for danger point guarding

Calculation of the safety distance for a SIMATIC FS400 3RG7845 light curtain with a
resolution of 14 mm for danger point guarding.
The safety distance "S" for guarding danger points is calculated in accordance with EN
999 with the formula:
S [mm] = K [mm/s] x T [s] + C [mm]
S = Safety distance in mm
If the result is less than 100 mm, a distance of at least 100 mm must still be
maintained.
K = Approach speed in mm/s
In the close area of 500 mm, the speed is calculated at 2000 mm/s. If the
distance is greater than 500 mm, K can be calculated as 1600 mm/s. In this
case, however, a minimum of 500 mm applies to the safety distance.
T = Total time of the delay in seconds
Total of:
the response time of the protective device t
the evaluation instrument, if any t
and the machine's stopping t
C = 8 x (d-14) in mm
Additional amount depending on the depth of penetration into the protective field
before turning on the AOPD
d = Resolution of the AOPD
a) See Chapter 12
b) See technical data of the data evaluation instrument
c) See technical data of the machine or stopping time measurement
a)
AOPD
b)
Evaluation instrument
c)
Machine
143