Safe2+ / Safe4
Operation Manual
8 www.cedes.com
©
CEDES
Safety & Automation AG / June 2008
5. Installation
5.1. Regulations and standards
The compliance with the fundamental health & safety
requirements as detailed in the EU Machinery Direc-
tive EC/98/37 and control reliability according to
OSHA 29 CFR 1910.212, ANSI B11.19 and ANSI
B11.20 has to be achieved with the correct imple-
mentation of safety components. With the help of a
hazard analysis as laid out in EN 292 and EN 1050,
a comprehensive safety evaluation has to be made
when designing and planning machinery and ma-
chinery control equipment. If Active Optoelectronic
Protective Devices (AOPD) are used, the required
safety distances, sufficient protective height and all
application conditions must be considered during the
planning phase.
5.1.1. Safety distance to danger point
According to the standards, the Safe2+ or Safe4 light
curtain and the point of danger must be separated by
a defined safety distance. This minimum distance
safeguards that the danger point may only be
reached after the hazardous motion has stopped.
The safety distance (see also standards EN 294, EN
775, EN 811, EN 999) depends on
•
Machine stop time
•
Response time of the protective device (light
c safety relays)
•
Resolution of the protective device
•
Approaching speed to the danger point
•
Position of the AOPD
The approaching speed is dependent on safety dis-
tance
S
as follows
S
≤
500 mm, speed = 2 mm / ms
S > 500 mm, speed = 1.6 mm / ms
In cases of 'vertical' installation of the light curtains
within an industrial environment and a resolution of
the light curtain system
d
, (where 14 mm
≤
d
≤
40
mm), the safety distance
S
to the point of danger is
calculated according to the formula:
For 100 mm
≤
S
≤
500 mm:
S = 2 mm / ms x T + 8 x (d - 14)
For S > 500 mm
S = 1.6 mm / ms x T + 8 x (d - 14)
S = Safety distance in mm
T = Total response time in ms
(machine stop time + Safe2+ / Safe4 response
time + safety relay response time)
d = Resolution of Safe2+ or Safe4 in mm
In the case of perimeter systems (chapter 4.5) or
light curtains with a resolution
d
> 40 mm the safety
distance is calculated for vertical mounted light cur-
tains and horizontal approach, according to the for-
mula:
S = 1.6 mm / ms x T + 850 [mm]
More detailed information regarding safety distance
and safety height can be found in EN 999 or EN 294,
depending on mounting type of application.
5.1.2. Height of protective field
The protective field is clearly visible as the black
area with the optical lenses on the emitter and re-
ceiver.
In addition the height of the protective field
A
is
found on the label of each system and in the selec-
tion tables, described in chapter 8.2 (resolution 14
and 30 mm).
Warning:
The laser beams of the ILAS are
not
part of to the
protective field.
Use only the protective field as mentioned on the
product label. Otherwise serious injury or death may
occur.
5.1.3. Response time – light curtain
The response time t
R
is found on the product label,
Configuration Tool or from the selection tables 8.2.
5.1.4. Distance to reflective surfaces
Reflective surfaces may cause specular reflections
within the emitter and receiver aperture angle, i.e. an
interruption of the protective field would not be recog-
nized (Figure 10).
dangerous point
reflective surface
E
R
optical axis
S
2
#
R
Figure 10: Distance to reflective surfaces
Should reflective surfaces arise, i.e. aluminium con-
tainer passing near the light curtain or if the danger
point itself is reflective, i.e. a steel blade, the safety
distance S
2
must be increased, such that no reflec-
tive surface lies within the distance S
2
.
The increase of the safety distance is dependant of
the actual operation range R according to IEC 61496
and may be calculated as follows:
Safe4
S
2
= 72 mm
für R < 3 m
S
2
= R x 0.0219
für R
≥
3 m
Safe2+:
S
2
= 131 mm
für R < 3 m
S
2
= R x 0.0437
für R
≥
3 m
The safety distance may also be calculated with the
Configuration Tool.
