General Safety Instructions; Appropriate Use; Application Regulations - schmersal SMS 3 Montage- Und Anschlussanleitung

2. General safety instructions

2.1. Appropriate use

The safety mat series SMS 3 is a
pressure sensitive safety device
used for the safeguarding of ha-
zardous areas around machines.
The tactile mat should be placed
on a flat smooth surface around
the machine. When designing ma-
chine safeguarding,
speed, safety distance and the
possibility of stepping behind or
bypassing of the safety device
must be considered.
The operator must not be able to
reach the nearest danger point
before the machine has stopped.
This is accomplished by the pro-
per calculation of the area dimen-
sions and installation of the tactile
mat(s). When choosing the safety
device, the valid regulations have
to be considered.
Safety categories in accordance
with EN 954-1 for pressure sen-
sitive mats (safety mats) on ma-
chines are stated in type C stan-
dards.
We recommend a general intro-
duction for the operator including
the features and function of the
safety mat as well as the protecti-
on zone.
For the appropriate use of the de-
vice, the following are required:
correct installation, commissio-
ning, testing and periodic in-
spection.
The safety requirements of the
machinery directive (98/37/EC)
and their appendices and amend-
ments, as well as the relevant
safety standards, must be adhe-
red to when designing a machine
or installing a safety mat.
2.2. Application
regulations
The correct positioning of the
tactile mats with regard to the
nearest danger point is mainly de-
pendent on the stopping perfor-
mance of the machine and the as-
sumed approach speed of the
approach
operator. In order to define the ap-
propriate safety distance the stan-
dard EN 999 (Safety of Machinery,
Hand/Arm-Speed) provides a for-
mula.
Safety distance:
S = K x (T1 +T2) + (1200 – 0.4 H)
S is the minimum distance in mi-
limetres, from the danger zone
to the detection point, line,
plane or zone
K is a parameter in milimetres
per second, derived from data
on approach speeds of the
body or parts of the body
H distance above the floor (i.e.
platform) in mm (for safety
mats this term is usually 0 mm)
T1 is the maximum time between
the actuation of the sensing
function (tactile mat) and the
output signal switching device
(OSSD; safety module) being in
the off state (response time see
"Technical
chapter 9)
T2 is the response time of the ma-
chine, i.e. the time required to
stop the machine or remove
the risks after receiving the
output signal from the protecti-
ve equipment
The safety distance can be calcu-
lated as follows:
S = 1600 mm/s x (T1 +T2)
+ 1200 mm
Example:
Calculate the safety distance for a
machine. The stop time is 117.5
ms, the response time of the tacti-
le mat and safety module is 70
ms. The tactile mats are at floor
level.
S = 1600 mm/s x (0,07 s + 0,1175 s)
S = 1600 mm/s x (0,1875 s)
S = 300 mm + 1200 mm
S = 1500 mm
The minimum width of the tactile
mat should be 750 mm (length of
stride).
specifications",
+ 1200 mm
+ 1200 mm
17