Rockwell Tools GUARDSHIELD SAFE 4 - Manual (Page 8)

GuardShield Safe 4 Operation Manual
5. Installation
5.1. Regulations and standards
The compliance with the fundamental health & safety
requirements as detailed in the EU Machinery Directive
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 implementation 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 machinery 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. IEC Safety distance to danger point
According to the standards, the GuardShield Safe 4
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
curtain + safety relays)
• Resolution of the protective device
• Approaching speed to the danger point
• Position of the AOPD
The approaching speed is dependent on safety
distance 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 GuardShield Safe 4 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 curtains and
horizontal approach, according to the formula:
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 North American Safety Distance Formulas
US Safety Distance Formula
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AT T EN T IO N : The G uardShield safety light
curtains m ust be mounted at a sufficient
distance from the pinch point or point of
operation hazard to help ensure that the machine
stops before a person’s finger, hand, arm(s),
or body reaches the hazard.
Figure 6: Perimeter Systems
(2 and 3 beams), accord. to EN999 (1998)