B
: PREPARING THE SITE
7
Figure 7:
Service
Conduits
PLACING THE VEHICLE DETECTOR LOOPS
Proper placement of vehicle detector wire loops is critical if the loops
are to provide satisfactory, extended service. The most important
considerations are: 1) Proper wire type and, 2) Good, tight connections
from the loop to the loop terminating connector. When a "Stand
Alone" vehicle detector is used, the detection loop is connected to the
wire harness on the detector itself. (See WIRING VEHICLE
DETECTORS, Page 10.)
The LPX1000 provides for the use of two loop systems: 1) A
"reversing" loop that will prevent the gate from closing on a vehicle
that has stopped in the path of the gate and, 2) A "free exit" loop that
will open the gate by detecting a vehicle which is inside the gated area
and wishes to leave. If "free exit" detection is not desired, this loop
will not be needed. Note the "reversing” loop is normally made up of
two loops connected to one detector. See Figure 8 above.
Two different types of installations will usually be encountered: 1) If
the driveway material is already in place, saw cuts will be needed to
accommodate the loop wires.
2) For loops where the paving material will be installed after the loop
is positioned, it is necessary that the loop wires be placed in Schedule
40 PVC pipe to maintain uniform loop spacing with respect to the
surface of the pavement. The loop should be placed 1.5 inches below
the surface of the pavement and at least 2" above any reinforcing steel
The lead-in wires need not be in PVC, but must have at least six (6)
twists per running foot.
RISK OF ENTRAPMENT
Vehicle detector loops will not detect smaller vehicles such
as motorcycles, golf carts, bicycles, or pedestrians.
Photoelectric detectors, edge detectors and separate
pedestrian access must be installed.
W A R N I N G !
Figure 8: Loop Diagrams
GATE
WEATHERPROOF/
POWER CONDUIT
HIGH VOLTAGE
115 VAC
POWER SWITCH
LOCKABLE
POWER CONDUIT
HIGH VOLTAGE
FOR 115 VAC
ALTERNATE WIRING
LOW VOLTAGE
CONDUIT FOR
WIRING AUXILIARY
DEVICES TO
TERMINAL STRIP
BOX
CONNECTION
115 VAC LINE
BOX (OPTIONAL)
