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Contrinex Industrial Electronics
The choice of an active optoelectronic protective device (AOPD), such
as a safety light curtain, depends on:
–
The relevant safety standards to be applied
–
The definition of the safeguarding function
–
The available space around the hazardous area
–
The safety distance, as calculated by the appropriate formula and
depending on the AOPD’s resolution and position, as well as the re-
sponse times of the light curtain or access control barrier, the safety
relay and the machine stopping time
–
Ergonomic factors (e.g. how often access is necessary)
–
Commercial criteria
SAFEGUARDING FUNCTION
The AOPD resolution must be chosen according to the application and
the required safeguarding function. It is defined as the minimum size of
an object that can be reliably and safely detected at any position in the
protective field. Basically, two approaches can be considered:
–
Point of operation: detection of hands entering the defined hazard-
ous area. The protective equipment immediately stops the machine
or renders it harmless. The Safetinex YBB range is best suited for
this type of application.
In both cases, the primary function of the protective device is to stop
the machine before the hazardous point is reached and to prevent un-
intentional machine start-up or restart. This function must comply with
the category or performance level of the safety-related components of
the machine’s control system.
HAZARDOUS AREA
The hazardous area can be defined in terms of:
–
The dimensions of the zone that requires protection
–
The different access points to accessible hazards
–
The risk of an undetected presence in the hazardous zone, or risk of
bypassing the protective device
AOPD DETECTION CAPABILITY
The light curtain or barrier detection capability (or resolution) depends
on the distance between the centerlines of each beam emitted by the
sender. The choice for a specific resolution depends on the part of the
body which needs protection.
