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Notes
6.6
Installation of operation switches
Operation/command devices must be placed such as to ensure easy access from inside the
vehicle. They must be in direct visual contact with regard to barrier. Poorly placed switches and
pillars represent possible safety hazards.
6.7
Usage of Photocells
Photocells are especially suitable as an alternative to a contact loop; though even more effective
in combination with a safety loop. Especially when trailers, campers or trucks with trailers pass
through the barrier, Photocells are perfect. Ideally Photocells are positioned directly under the
barrier in order to recognize an object and delay the closing motion. They may also be installed
behind a barrier so as to send a further signal and thus prevent the barrier from closing or delay
the closing motion some more. The height of the installation depends on the situation and should
be located at a position which does not let the invisible light beam transmit underneath the
vehicles (truck, SUV).
Reflector Photocells are not suitable for operation, as vehicle finishes, sun or strong rain lead to
incorrect reflector operation.