Calculating the minimum distance according to ISO 13855
The calculation of the minimum distance is based on international or national stan‐
dards and statutory requirements applicable at the place of installation of the machine.
If the minimum distance is calculated according to ISO 13855, then it depends on the
following points:
•
Machine stopping time (time interval between triggering the sensor function and
the end of the machine’s dangerous state)
•
Response time of the protective device
•
Approach speed of personnel
•
Type of approach: orthogonal (at right angles)
•
Parameters specified based on the application
For the USA (scope of OSHA and ANSI), different regulations may apply, e.g.:
a) Laws: Code of Federal Regulations, Title 29 (CFR29) Part 1910.217
b) Standards: ANSI B11.19
Complementary information
Additional information is available in the ISO 13855 standard and in the Guidelines
Safe Machinery.
SICK offers a stopping/run-down time measurement service in many countries.
Further topics
•
4.3.2.1
Calculating minimum distance from the hazardous point
Important information
DANGER
Minimum distance from the hazardous point is too small
The dangerous state of the machine may not be stopped or not be stopped in a timely
manner due to a minimum distance that is too small.
b
Calculate the minimum distances for the machine in which the multiple light beam
safety device is integrated.
b
When mounting the multiple light beam safety device, observe the minimum dis‐
tance.
Approach
The example shows the calculation of the minimum distance for an orthogonal (at right
angles) approach to the multiple light beam safety device. Depending on the applica‐
tion and the ambient conditions, a different calculation may be required (e.g., at a dif‐
ferent angle to the direction of approach or an indirect approach).
1.
Calculate S using the following formula:
S = 1,600 mm/s × T + C
where:
°
S = minimum distance in millimeters (mm)
°
T = machine stopping time + response time of the protective device after
interruption in the light path in seconds (s)
4
PROJECT PLANNING
20
O P E R A T I N G I N S T R U C T I O N S | deTem4 LT Muting A/P
8024802/2020-07-17 | SICK
Subject to change without notice