Allen-Bradley 442L-SFZNMN, User Manual

Page: 42 / 108

42 Rockwell Automation Publication 442L-UM005B-EN-P - April 2017
Chapter 4 Mounting
Calculate Minimum Distance S
See EN ISO 13855. Calculate S with the following formula:
S = (K × (T
M
+ T
S
)) + Z
G
+ Z
R
+ C
Response Time T
S
of the SafeZone Mini Device
The response time T
S
of the SafeZone Mini device depends on the following:
• The basic response time of the SafeZone Mini device.
• The multiple sampling set.
See OSSD Response Times on page 84 .
Supplement Z
R
for Measurement Errors Caused by Reflection
Supplement C for Protection Against Reaching Over
With a protective field installed horizontally, there is a risk that people may
reach over the protective field and in this way reach the hazardous area before
the SafeZone Mini device shuts down the dangerous state. For this reason, the
calculation of the minimum distance must take into account a supplement to
help prevent persons from finding themselves in a hazardous situation by
reaching over (see EN ISO 13857) before the SafeZone Mini device triggers.
The necessary supplement for the minimum distance is dependent on the
height of the scan plane for the protective field. In Figure 16 , At low heights (1)
the supplement is larger than at greater heights (2 and 3).
Variable Description
K Approach speed (1600 mm/s (63 in./s), defined in EN ISO 13855)
T
M
Stopping/run-down time of the machine or system
T
S
Response time of the SafeZone Mini device and the downstream controller
Z
G
General safety supplement of the SafeZone Mini device = 100 mm (3.94 in.)
Z
R
Supplement for measurement error that is related to reflection
C Supplement for prevention of reaching over
ATTENTION:
Avoid mounting retroreflectors at a distance of less than one
meter from the boundary of the protective field.
With retroreflectors that are positioned at a distance of less than 1 m (3.28 ft)
from the boundary of the protective field a supplement Z
R
of 200 mm
(7.87 in.) must be added to the protective field.