Controlled Products Systems Group HRG 220-A ST - Manual (Page 54)

Installation and Maintenance Manual
40
Installing Photoelectric (Non-contact) Sensors
General Information:
Follow the guidelines in the Entrapment Protection Schematic to plan the most appropriate mounting
positions for the photo-eye sensors to be installed. If there are no other secondary external entrapment
protection sensors (typically an edge sensor), at least two photoelectric sensors are required to serve to
reverse the gate in each direction of travel. The Smart Touch Controller has two photoelectric sensor
inputs (Photo eye open and Photo eye close).
There are two common types of photoelectric sensors, thru beam and retro-reflective, each has some
advantages. A thru beam sensor is generally more powerful and able to function reliably with dirty optics
and in poor weather. A retro-reflective sensor has the convenience of not requiring the installation and
electrical wiring of the remote emitter required in a thru beam system, but is generally more problematic
in poor weather. Avoid use of a retro-reflective device to span a distance greater than 24 feet in an
outdoor environment or performance will probably be unsatisfactory.
Compatibility:
A requirement of the UL 325 standard is that a photoelectric sensor be laboratory tested and
―recognized‖ under UL 325. In order to be compatible with a HySecurity operator, a photo eye must be
rated to function from 24 Volts DC source power.
Installation:
Mount the photo eyes approximately 15‖ to 30‖ above the ground and as close to the gate as possible.
Unless there are also gate edges for entrapment protection, a minimum of two photo eyes will be
required to function for both the open and closing directions of travel. Mount the receivers on the left and
right sides of the gate operator and the emitters just beyond the travel of the gate in both the full open
and full closed positions of travel. In some situations, an additional photo eye should be installed on the
public side of the gate. The installation locations described above are intended for pedestrian detection,
if photo eyes are also to be used for vehicular detection, consider, in addition to the low elevation photo
eye for cars, another photo eye at a height of about 55‖ to detect semi-trucks.
Configuration:
If the photo eye has an internal switch for setting Light Operate vs. Dark Operate, select Light Operate.
If the photo eye has a relay output and has both NO and NC terminals, some experimentation may be
required to determine the proper connection. This is because in the Light Operate mode the output relay
is normally energized and releases when the beam is blocked. Some manufacturers label an output as
NO, when it is actually an NC contact. If the photo eye has a solid-state output and provides the option
of a sinking or sourcing connection, choose the sinking connection.
Connection:
Three wires to the receiver and two wires to the emitter are all that is required.
a. The +24 Volt source power is obtained from our power supply board.
b. The
–24 Volt source power is obtained from our terminals #14 or 15, labeled (Photo Eye
Power) on the Smart Touch Controller board.
Note: The
–24 Volt Photo Eye Power also supplies the photo eye Common.
c. The photo eye NO or NC output connects to the Smart Touch Controller board at terminal
#19 if the photo eye spans the road, or at terminal #17 if the photo eye spans the gate’s
open position storage area.